I was shooting some new Underwood 200 XTP's through my chronograph this weekend and just seeing how they shot since they just came in the mail. I go to pick up my brass and I have a case blown out. I am trying to attach a picture below. I will also be posting pictures of the box and lot number as soon as I figure out how if this doesn't work. What does every one here think could have caused this its not in the normal location and it seems almost like the brass was a bit long and the bullet wedged it against the barrell and then the slide unlocked and pulled it back causing it to tear with pressure inside but that corner of the brass wedged maybe. Not sure at all it was somewhere in the middle of about 19 shots. Average was 1269 fps has two weird high numbers not sure if I shot way high in the chrono or not. One was somewhere in the 1300+ range and the other was 1400 something. I don't have the numbers in front of me now.
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Lot Number followed by box with load information from underwood.
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Box
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There is a small smile in each piece of brass. Total out of 19 rounds 4 pieces of brass had smiles. The rest just had a pretty good sized bulge.
doverpack12, while it is not a good thing to have brass crack or split, it does happen. The treatment process may have left the brass harder/brittle, this can be further aggravated by the loading process. I have seen many Federal 10mm factory brass split upon the initial firing. The Underwood numbers do indicate some higher pressures at those velocities.
That brass may have been damaged in the loading process and turned loose upon firing. If it did not happen to a whole bunch of the casings I'd say the ammo is good to go!
About your higher numbers, try backing away from the Chronograph at least 10' to 15' will help attain better results. And eliminate blast issues.
Be sure to clean the chamber well
doverpack, what gun are you firing these out of? How long is the barrel? What is the headstamp on the brass?
I would not fire any more of those rounds in that gun!
Is this the new ammo that is actually nickel and not brass? I have heard that nickel is more brittle than brass.
Why does the right side look taller. Top view picture please.
It looks to me like the torn material has shifted upwards, but without more pictures it's difficult to say what for sure happened. It does look like brittle brass. This type of case failure isn't too dangerous (not like a web blowout) but if the brass is that brittle it could increase the likelihood of other failures. I want to know if this is Starline brass.
I will trade or purchase the remainder when/if you decide. ;D
Quote from: doverpack12 on May 15 2013 11:26:12 AM MDT
I was shooting some new Underwood 200 XTP's through my chronograph this weekend and just seeing how they shot since they just came in the mail. I go to pick up my brass and I have a case blown out. I am trying to attach a picture below. I will also be posting pictures of the box and lot number as soon as I figure out how if this doesn't work. What does every one here think could have caused this its not in the normal location and it seems almost like the brass was a bit long and the bullet wedged it against the barrell and then the slide unlocked and pulled it back causing it to tear with pressure inside but that corner of the brass wedged maybe. Not sure at all it was somewhere in the middle of about 19 shots. Average was 1269 fps has two weird high numbers not sure if I shot way high in the chrono or not. One was somewhere in the 1300+ range and the other was 1400 something. I don't have the numbers in front of me now.
For a 200 grain bullet? :o
No wonder you had a case blow out.
I doubt the readings were correct. If you chronograph enough you get grossly false readings every so often. That's why it is better to do long strings and write it down after every shot.
Yes, I would be interested to see how the rest of the lot chrono's.
Hard to tell from the photo...But do those case heads look swollen to anyone else? Dover, do you have calipers you could measure the case head with?
They do show some case expansion in the pictures...I tend to thing the case may have be trimmed poorly or damaged prior to or during the loading process. Looking at the section that looked like it was inside the chamber at firing! Machines can cause damage if somethings are out of tolerance... ???
BTW DT did have some brass that was less than desirable as people did experience splits...His brass may not be made by Star Line from what I read awhile back. I think he found an overseas supplier if I recall. :'(
Yep...And I have had some split before too on first firing. Usually Federal, as you mentioned.
I was looking over the DT ammo that came with my new G-20SF purchase, the primers are concaved slightly. Not sure what's up with that... ??? Seater punch must be wrong or worn to a rounded over shape! ::)
I also would like to know what gun they were fired in and what if any mods were done to the gun.
Quote from: doverpack12 on May 15 2013 11:26:12 AM MDTAverage was 1269 fps has two weird high numbers not sure if I shot way high in the chrono or not. One was somewhere in the 1300+ range and the other was 1400 something.
WOW!!! Houston, we have a problem. ;D
Did the ammo really manage it? Did the Chrono have a brain fart? Either way, no doubt two nickel plated brass cases ended up in a way they shouldn't have.
Quote from: 4949shooter on May 16 2013 06:42:31 AM MDTYes, I would be interested to see how the rest of the lot chrono's.
I second the motion. But with the next go around each round should be chronoed and the spent brass casing checked on an individual basis. BTW, video of said testing would be awesome. Or at least it could be. :-\
Sorry I had a very busy end of the week. This was a stock G20 SF only modification was a 22 lb ISMI recoil spring was installed on a SS guide rod. The right side
of the left case is sticking up past where the rest of the neck is. This was due to the tear in the brass. I was almost thinking it got caught in the barrel with the
bullet then the pressure started to push the slide back and it tore it until the bullet made it past the brass edge in the barrel. The brass head stamp is Underwood
and it is nickel. This is the most recent run of 200 XTP that he had up near the end of the week April 22-26. I typically kneel about 20 feet back from the chrono
otherwise mine is pretty picky and doesn't even read sometimes. I do believe those two high velocities the first time were due to either bad shots by me or
chrono errors. I can chrono some more memorial weekend and inspect each brass piece individually and compare it with its velocity. I will measure the head of
these brass cases next weekend as well. These two smiled and there are two more with slightly less severe smiles, this was out of 19 shots. If I missed replying
to any questions ask again. Please feel free to suggest anything that you feel may have happened.
Quote from: doverpack12 on May 18 2013 07:39:13 AM MDT
Sorry I had a very busy end of the week. This was a stock G20 SF only modification was a 22 lb ISMI recoil spring was installed on a SS guide rod. The right side
of the left case is sticking up past where the rest of the neck is. This was due to the tear in the brass. I was almost thinking it got caught in the barrel with the
bullet then the pressure started to push the slide back and it tore it until the bullet made it past the brass edge in the barrel. The brass head stamp is Underwood
and it is nickel. This is the most recent run of 200 XTP that he had up near the end of the week April 22-26. I typically kneel about 20 feet back from the chrono
otherwise mine is pretty picky and doesn't even read sometimes. I do believe those two high velocities the first time were due to either bad shots by me or
chrono errors. I can chrono some more memorial weekend and inspect each brass piece individually and compare it with its velocity. I will measure the head of
these brass cases next weekend as well. These two smiled and there are two more with slightly less severe smiles, this was out of 19 shots. If I missed replying
to any questions ask again. Please feel free to suggest anything that you feel may have happened.
This can't happen, unless there something seriously wrong with your pistol. The breach doesn't move from the barrel until after the bullet is long gone, from the muzzle. It's the gas exiting the muzzle, NOT the detonation, that begins the action cycle. Either something else caused the brass to "stick" to the chamber, or the brass was defective or damaged during assembly. Even if your chrono velocities were accurate, I don't see anything alarming about it. I've gone significantly greater than that, and the typical pressure signs were very evident. Ramp smile, case web expansion and primer extrusion, but nothing catastrophic. If you were using an OEM Glock barrel, the results you see are at the wrong end of the case to be a pressure issue. Case smiles aren't uncommon with Underwood 10mm, in any barrel.
As far as the brass source goes, you'll have to confirm that with Underwood. I suspect it isn't Starline, as they don't stock nickel, and the unique head stamp requires a custom run. Starline only does nickel brass in drum-lots, with a long lead time. There's almost no way Underwood got custom Starline nickel brass on short notice because they were out of regular bulk. They're backlogged for months on custom orders. A drum quantity is about 8,000 pieces, and 3 drums are required for bulk discount. The custom head stamp is not significant, as Starline is already tooled for Underwood's (initial expense already paid). I think he got the brass somewhere else, perhaps Armscor Intl (probably offshore mfg). If it were a contract fulfillment production, surely it wouldn't have been nickel, as this adds to delivery time and cost. I dunno. Ask him.
Quote from: doverpack12 on May 18 2013 07:39:13 AM MDT
Sorry I had a very busy end of the week. This was a stock G20 SF only modification was a 22 lb ISMI recoil spring was installed on a SS guide rod. The right side
of the left case is sticking up past where the rest of the neck is. This was due to the tear in the brass. I was almost thinking it got caught in the barrel with the
bullet then the pressure started to push the slide back and it tore it until the bullet made it past the brass edge in the barrel. The brass head stamp is Underwood
and it is nickel. This is the most recent run of 200 XTP that he had up near the end of the week April 22-26. I typically kneel about 20 feet back from the chrono
otherwise mine is pretty picky and doesn't even read sometimes. I do believe those two high velocities the first time were due to either bad shots by me or
chrono errors. I can chrono some more memorial weekend and inspect each brass piece individually and compare it with its velocity. I will measure the head of
these brass cases next weekend as well. These two smiled and there are two more with slightly less severe smiles, this was out of 19 shots. If I missed replying
to any questions ask again. Please feel free to suggest anything that you feel may have happened.
Thanks for the info. Helps put things into a more definitive perspective. At the end of the day it's hard for me to come to any other conclusion than Underwood loading those 10mm rounds beyond what Kevin originally intended. Not good. Supposedly he's correcting the issue. My question now is; When did Kevin adjust his 10mm loads? Before or after your lot?
After.I have the same lot.. However, this ammo insanity is causing issues.
Well, at least initiative has actually been taken to correct these issues. Hopfully nothing catastrophic happens as a result of other older overpowered lots still floating around out there.
Another explanation for one of the high readings you got on the chrono is that one or more of the bullets in that box was the wrong weight. I bought some 200 grain xtp's on 4/27 and the first one I pulled out of the box was a 155 grain xtp in the nickel case. Someone must have picked up some from a drum and then droped them in the wrong drum not paying attention to what they were doing? Also are you guys using the date of puchase or date listed as the lot# or is there an actual lot number I'm missing somewhere.
Nobody has Gas Ammo beat. I thought I had 180 XTP's and when The Shadow did the tear-down they were all 200 XTP. Sadly, they don't even carry 200 XTP :o
Quote from: REDLINE on May 18 2013 04:36:15 PM MDT
Well, at least initiative has actually been taken to correct these issues. Hopfully nothing catastrophic happens as a result of other older overpowered lots still floating around out there.
Amen.
We will have to chrono the new and corrected lots to see what they are doing, quality control, deviation, etc.
I was using the numbers on the end flap of the box as the lot number. They have to be his most recent run because there haven't been any available since then.
I put a picture of this number at the top of the first page of the thread.
I was going to mention it earlier, but that number (UA45) refers to the packing box model. The 45 ammo box works for 10mm.
The boxes get printed with the label for the company like Underwood. His info should be on the sticker on the outside of the end flap. Maybe he is using the Item number to reference his lot. However that doesn't really provide enough data. :-\
Also a Lot number should be clearly marked, I don't know what he is doing to keep track of different lots! That could be a potential problem... ???
I have the same #'s on my batch in Nickel.
Quote from: Von on May 18 2013 05:51:26 PM MDT
Another explanation for one of the high readings you got on the chrono is that one or more of the bullets in that box was the wrong weight. I bought some 200 grain xtp's on 4/27 and the first one I pulled out of the box was a 155 grain xtp in the nickel case.
That is simply unacceptable. This is reason #2 I reload. Reason #1 being manufactured ammo rarely performs at advertised specifications.
All visible markings I can find on the box are shown in the pictures
No lot/batch numbers on any of my Underwood ammo. Maybe the delivery guy dropped that box.... more reason for me to start reloading.
Changed to a ISMI 24 lb recoil spring today from the 22 lb I had in and shot some more Underwood 200 XTP from the same box I had the blowout I first posted on the thread. Well HAD ANOTHER today not the same though. Picture below shows it. These shoot great other than the brass no being up to par or the loads being too hot for it.
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That brass has to be brittle, not annealed properly or alloy mixture issue ???
Bad brass! It looks like it's too brittle. Looks like the new batch/supplier didn't work out too well
I only shot 3 times. One had a small smile then there was this piece that split and the third looks fine. Two were almost touching right where i was aiming and the third was about 6" right could have been me but i felt good about the shot until i saw the impact location.
Wow. Wish we knew the make of brass.
It's going to be Starline. Kevin has never used anything but Starline.
Quote from: Intercooler on May 25 2013 03:29:35 AM MDT
It's going to be Starline. Kevin has never used anything but Starline.
I don't think so. He couldn't get his "regular" Starline order, so he had to get "something else". Starline is backordered on 10mm, months away, the reason he can't get enough. Starline didn't "just happen" to have a supply of nickel brass (with his headstamp) laying around to get him by until the regular order shipped. Nickel order lead times are further out than plain brass (3-6 months, by recent reports, no exceptions). He went to another bulk supplier, that somehow was able to fill a large custom order in a short period. This means it's a "less popular" supplier, which usually indicates "less desirable", or a supplier not used by any other major ammunition manufacturer. Probably Armscor or one of their subs (possibly overseas, indicated by the short lead period), which could explain the quality issue. The failures you've seen here are not common of Starline brass, plain or nickel. If Starline were, somehow, able to fill an order of nickel brass, they surely would have been able to fill a plain brass order in the same or less time. Kevin apologized for having nickel brass, but I think he was apologizing for more than just that.
Quote from: DM1906 on May 25 2013 08:18:49 AM MDTKevin apologized for having nickel brass, but I think he was apologizing for more than just that.
this begs a Noob Question... is nickel plated brass less desirable from a reloading perspective?
Quote from: s0nspark on May 25 2013 08:40:17 AM MDT
Quote from: DM1906 on May 25 2013 08:18:49 AM MDTKevin apologized for having nickel brass, but I think he was apologizing for more than just that.
this begs a Noob Question... is nickel plated brass less desirable from a reloading perspective?
No. I prefer nickel. Some don't. Why he did, I dunno. It couldn't be just the cost, as the difference is a few pennies per box.
Picture of the headstamp on the brass so we can solve the puzzle.
Quote from: DM1906 on May 25 2013 08:18:49 AM MDTQuote from: Intercooler on May 25 2013 03:29:35 AM MDTIt's going to be Starline. Kevin has never used anything but Starline.
I don't think so. He couldn't get his "regular" Starline order, so he had to get "something else". Starline is backordered on 10mm, months away, the reason he can't get enough. Starline didn't "just happen" to have a supply of nickel brass (with his headstamp) laying around to get him by until the regular order shipped. Nickel order lead times are further out than plain brass (3-6 months, by recent reports, no exceptions). He went to another bulk supplier, that somehow was able to fill a large custom order in a short period. This means it's a "less popular" supplier, which usually indicates "less desirable", or a supplier not used by any other major ammunition manufacturer. Probably Armscor or one of their subs (possibly overseas, indicated by the short lead period), which could explain the quality issue. The failures you've seen here are not common of Starline brass, plain or nickel. If Starline were, somehow, able to fill an order of nickel brass, they surely would have been able to fill a plain brass order in the same or less time. Kevin apologized for having nickel brass, but I think he was apologizing for more than just that.
DM1906; I was thinking the same thing.
Either way it is irresponsible for any manufacturer compromise shooter safety by using low quality brass. The new nickel brass obviously wasn't tested with the higher pressure loads.
Tim Sundles may be using different bullets in his #21b load, but the brass is obviously of quality as we have not heard of KB's or split casings with his ammo up to this point.
Let's not condone lack of quality or testing where shooter safety is a concern.
Rather than speculate I just called ;)
Starline Starline Starline.... with Underwood headstamp just like I thought. For whatever reason with the Nickel plated Kevin said their has been a few split cases and he will exchange them for those concerned. OP you can phone him up if you haven't done so already and he will swap you out. He is about as easy of a person to talk with as anyone I know and will do whatever is needed. Even answers on the weekend!
I'm fine with the ones I have. I did take a picture of the brass headstamp as requested.
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Quote from: Intercooler on May 25 2013 01:33:32 PM MDT
Rather than speculate I just called ;)
Starline Starline Starline.... with Underwood headstamp just like I thought. For whatever reason with the Nickel plated Kevin said their has been a few split cases and he will exchange them for those concerned. OP you can phone him up if you haven't done so already and he will swap you out. He is about as easy of a person to talk with as anyone I know and will do whatever is needed. Even answers on the weekend!
IC, did you asked him if he tested the new cases? What did he say about the splits?
Since I just spoke with him 10 minutes ago now would be fine to call for an exchange if you want. I relayed to him about the 180 test the other day and being in the #3 spot now :o He's good with it and confirmed the downloading. 8)
Well at least they are taking some responsibility. Now we just have to ensure quality components are being used and we will be good to go!
I might even order from them again. ;)
He said a few case splits have been reported with one swapped out. I'm a little shocked that anyone with a case split or three doesn't take advantage of the offer. Could be something in the plating process where the loads have to be backed down a ton more. I'm no Nickel plated brass expert but the only split I ever had too. Maybe that is why it isn't really used in 10mm? Beats me.
I don't know, but the only other ten mil loads with nickel cases I can think of are the low powered Federal Hydrashok and the Remington 180 grain fmj.
Where did DM1906 go? He had all the answers and might know something about Nickel plated brass as it relates to 10mm ;D
Quote from: doverpack12 on May 24 2013 08:28:12 PM MDTChanged to a ISMI 24 lb recoil spring today from the 22 lb I had in and shot some more Underwood 200 XTP from the same box I had the blowout I first posted on the thread. Well HAD ANOTHER today not the same though. Picture below shows it. These shoot great other than the brass no being up to par or the loads being too hot for it.
Did you happen to chrono these 3?
The rounds in the first batch you shot seemed to be clearly over pressure if your chrono was giving correct readings.
If they were, and in conjunction with a stock glock barrel that has a very generously sized chamber, I don't think it's much of a leap to see how case splitting in this instance would be greatly enhanced no matter what brand of brass was used. On top of that I wonder if nickel plated brass makes it worse yet.
At the same time I would think the primers in the cases should be at least just about falling out too though, and they don't seem to be. So I just don't know.
Quote from: Intercooler on May 25 2013 03:01:27 PM MDT
Where did DM1906 go? He had all the answers and might know something about Nickel plated brass as it relates to 10mm ;D
Sorry. Been out of town most of the day. Back just now.
I still don't buy it. Unless he had a pending order (why would he apologize for something he planned?... that still doesn't make sense....), either he isn't being truthful (to his knowledge or not), or Starline isn't. 3-6 months is 3-6 months, and Starline's policy is first-come-first-serve, no matter how much you order. Midway had Starline nickel for a couple hours, and plain brass for over a week.
I dunno. I've used a lot of Starline nickel brass, in 10mm and a dozen other calibers, and have NEVER experienced that level of failure, or ANY failure above what may be expected from a similar quality level brass. I've split some, and had other failures, but NONE on the first firing, or not due to my actions. I can't believe Starline made a bad batch of brass, just for Kevin. I have a current lot of Starline nickel (with various headstamps) that I beat the snot out of. No splits. Not even full-nuclear 9x25D I sized from the same 10mm.
Maybe they got a bad batch. But, it's so rare with Starline, I'll have to convene a Congressional committee to believe it (unless they plea the 5th).
Feel free to phone him up to pick his brain. Maybe you can ask the right questions to get the information about the Nickel. I remember when I spoke to him a while back when getting the Underwood headstamp it was a considerable commitment. Possibly it was part of that which included some Nickel. I knew he has only used Starline since inception ;D
Quote from: Intercooler on May 25 2013 06:06:56 PM MDT
Feel free to phone him up to pick his brain. Maybe you can ask the right questions to get the information about the Nickel. I remember when I spoke to him a while back when getting the Underwood headstamp it was a considerable commitment. Possibly it was part of that which included some Nickel. I knew he has only used Starline since inception ;D
I'm not disagreeing with you, or disbelieve you. Just saying the story doesn't add up without more detail. I don't use his products, but know a lot of people who do, the reason for my concern. He told you. You told me (us). A commitment for a headstamp is not considerable, in any way other than cost of tooling. His volume justifies it, I'm sure, but I seriously doubt a "nickel" requirement was part of it. If there were a nickel commitment, we're back where we started. It was planned, but he apologized for it when it happened. The message I saw about the "new" use of nickel brass sounded like it was a last-resort option he hadn't planned, and had no choice, if production was to continue.
I did chrono those three but I'm pretty sure the sun was messing with my chrono because I also shot factory silvertips and double tap nosler 200 grainers and they were all quite high. I normally get around 1175 with silvertips and 200 noslers and instead I was 1350 plus. Same with the Underwood rounds except one a cloud came over and I got 1262 fps. I was shooting one shot recovering the brass and then recovering the bullet so I had some time between shots. I don't believe for a second any one of the three was going 1350 so I'm almost convinced it was the lighting on my chrono. I was using the sky screens but the sun was early in the moring and at an angle. I may try again this weekend.
What model chronograph are you using?
Regardless, no doubt it was off.
I'll be interested in seeing your further results if you make it out this weekend to give it another go in the hopes of good chrono data and more brass to inspect.
Did you notice loose primers in the cases that split?
Things to remember for best chrony use...
You need to have 10-12 feet of distance between the muzzle and the first sensor screen to eliminate blast effects and powder particles from yielding false readings. Yes, lighting is important but usually that yields no readings error. Battery voltage is also need for most accurate readings.
The sensor sees the bullet as a shadow to trip the timers, some actually blacken the projectile with a marker, as the shiny may be missed.
Since changing my Sky Cloud (hoops) and using them every testing session my readings are very good with no odd readings. You can shoot without them and get readings but with them in place I think it's better.
I did not notice loose primers in the cases that split and the ones that passed inspection were actually harder to re-prime than most other starline brass. I have an alpha chrony model. I will try a new battery. I always use the sky screens and I had problems when I was 10-12 feet away so I moved back to 20 and seem to get good consistent readings there. I will try to blacken the bullet with a marker as well. Any other suggestions are appreciated.
For chrono (Chrony) use during low light (dawn/dusk, no direct sunlight), or on overcast days, I don't use the screens. The screens block too much light. A cloudy day is almost always the best, with no screens. I also use a silver colored Easy-Up canopy over it on occasion during mid-summer. Blackening the bullet does help during low-angle direct sunlight, but shading the chronograph (bullet path) works best.
Just to be correct with the terms...
Sky Screens are the sensors (black boxes housing sensors) looking up through a window for a bullet shadow on the white/sky background.
Diffusers (simulated clouds) are the white plastic pieces positioned over the Chronograph in an Arc fashion to give a contrast of the bullets shadow as it passes through the Sky Screens at their set distance of 12".
You could actually take the Sky Screens out and put them in a table, etc... and it will function the same as in the box if you make the distance between them exactly 1'.
Diffusers and skyscreens are the same thing. Shooting Chrony calls them diffusers. Competitive Edge Dynamics (CED) calls them skyscreens.
Different chronographs do not all have a 1' spacing for the skyscreens. My CED M2 chronograph sensors are set exactly 2' apart.
The sensors are simply the sensors but always built inside of a general housing that varies among manufacturers of chronographs.
Some chronographs are better worse at reading velocities in low light and at being capable of reading a greater or lesser range of velocity depending on chips/circuitry/microcontrollers used.
Oh, a different unit than most use. I use the Chrony terminology because most people use it.
My chrony likes NO diffusers on a cloudy day. Here in Houston once the sun gets at a certain angle (. about 10 am in summer) I get high velocity readings- ALWAYS.
Sean
And that makes the point on why the CED M2 chronograph is so awesome but also costs the wopping $200 it does. Doesn't matter if it's 8am or just a bit before the sun rests on the horizon to the west, it has no problem giving accurate readings the whole time. Whether it's cloudy or not it doesn't care if you leave the skyscreens on all the time. Its sensitivity is awesome.
That's part of the reason it costs the $200 most don't want to spend on it in favor of $100 or less for lesser units. You get what you pay for in this instance. Plus replacement parts for the CED M2 are fairly inexpensive and readily available if you do shoot it, and you never have to worry about hitting the display/control buttons since they aren't part of the sensor/screen assembly.
I'm not saying the above to talk anyone into buying one for the reasons I listed above if they simply don't care about my above reasoning. But I also think some people pass on the CED M2 because they can't imagine it could be much better than lower cost units. In reality it is.
Kevin buddy just keep banging them out and working the ammo! Thanks for all you do!
Doubletap was the first to load full power 10mm like Underwood does and Swampfox did. Of course we know what doubletap did to their customers with the power levels and is now trying to get their customer base back from Underwood with hotter loads these days. The point I'm trying to make is Doubletap has always used Nickel plated cases and I've read opinions of reloaders on this forum that DT's caseings are the best quality for reloading with plated caseings. So nickel is not so unusual for 10mm.
I pick up a Double Tap Nickel case every 2-3 months at the range. Oddly, none have ever contained a primer :o
I always use the diffusers then to use Intercoolers terminology. Didn't have time between elk scouting trips today. Maybe tomorrow.
IIRC the Double Tap 10mm ammo seems to be loaded to an awefully high pressure for the low(er) velocity they put out, as verified by pressure signs after firing. Or maybe it's that they aren't always loaded consistently and it's a hit or miss kinda thing. How often, if I even have a clue what I'm talking about I don't know.
I had disected the DT 10mm 135gr load and it contained what was guessed by Taterhead and The_Shadow to be Hodgdon Longshot powder. It certainly resembles it. The charge weight(s) seem to be in the ballpark to me, but I'm not 100% on that.
The thread is here - http://10mm-firearms.com/reloading-10mm-ammo/disected-hornady-155gr-180gr-win-silvertip-175gr-blazer-200gr-and-dt-135gr/ (http://10mm-firearms.com/reloading-10mm-ammo/disected-hornady-155gr-180gr-win-silvertip-175gr-blazer-200gr-and-dt-135gr/)
The powder charge in the DT 10mm 135gr load was 11.2gr and 11.4gr between the two I disected. Those powder charge weights, if Longshot, seem quite reasonable to me if Longshot is the powder I found. COL was 1.241" for both.
Here's the pic of the powder;
(http://i1293.photobucket.com/albums/b600/REDLINE10mm/10mmDT135Nosler_zpsf706773d.jpg)
475/480 had worked up some Longshot 10mm loads with the 135gr Nosler, both loaded to a COL of 1.245", and chronographed them from both his G20SF (4.6" barrel) and his STI (6" barrel). The velocity results were as follows:
G20SF + 11.0gr = 1470 FPS
G20SF + 12.0gr = 1497 FPS
STI 6" + 11.0gr = 1613 FPS
STI 6" + 12.0gr = 1698 FPS
Double Tap claims theirs at 1600 FPS from the 4.6" barrel of a G20.
475/480's thread (showing many more load comparisons) can be seen here -
http://10mm-firearms.com/reloading-10mm-ammo/10mm-longshot-loads-sti-6'-and-g20sf-4-6'/ (http://10mm-firearms.com/reloading-10mm-ammo/10mm-longshot-loads-sti-6'-and-g20sf-4-6'/)
The comparison of Underwoods 135gr 10mm loads using IMR 800-X powder (before this load has very recently been backed down) is as follows;
From Me http://10mm-firearms.com/factory-10mm-ammo/finally-5-underwood-10mm-ammo-disections/ (http://10mm-firearms.com/factory-10mm-ammo/finally-5-underwood-10mm-ammo-disections/) -
The 4 rounds I disected ranged from 11.4-11.7 grains of 800-X and a COL ranging from 1.249"-1.252".
From The_Shadow http://10mm-firearms.com/factory-10mm-ammo/underwood's-lineup-135155165180220/ (http://10mm-firearms.com/factory-10mm-ammo/underwood's-lineup-135155165180220/) ;
1 round pulled had 11.8 grains of 800-X and a COL of 1.252". After reassembly the velocity through his S&W 1006 5" with the 22lb recoil spring was 1738 FPS in which a light smile showed on the brass and the primer fell out.
Chronographed more of the Underwood 200 XTP today. First I changed my chrono battery and adjusted so I was shooting a little more level through it. Seemed to fix the problem. Anyway they averaged the exact same 1263 fps shot from about 20 feet from chrono. Previously I got 1264 fps. No split brass this time and no smiles. Velocities were not near as extreme had on 1288 on the first shot and then everything else was 1250-1265. This was from the next box since my partial of the other one is gone. Seems maybe the powder measure got away on a few rounds which ended up in the last box or something to cause some low 1300 fps readings which I believe were correct.
Sounds good!
Ditto for Sounds Good!
....Or it could be climate/weather related. Some powders are more sensitive to it than others. 800X being one of them, in my experience.
I sure hope those 200 grain xtp's are good to go because I got 300 rounds of those loads around the first of may. I haven't gotten out to shoot any of them yet though. It sounds like they are from the same run as the Op's. I just wish they had lot numbers on the box like most manufacturers of ammo.
All days I shot were roughly the same weather conditions. Partly cloudy and around 60 degrees F.
Quote from: doverpack12 on May 28 2013 08:12:31 AM MDT
All days I shot were roughly the same weather conditions. Partly cloudy and around 60 degrees F.
There's more to it than just that. A box of bullets in direct sunlight, even for a short period, can increase the cartridge temp considerably, and a hot pistol will develop different pressures than when cold. Barometric pressure and humidity have a great affect, as well. When the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.
Quote from: DM1906 on May 28 2013 09:59:46 AM MDT
Quote from: doverpack12 on May 28 2013 08:12:31 AM MDT
All days I shot were roughly the same weather conditions. Partly cloudy and around 60 degrees F.
There's more to it than just that. A box of bullets in direct sunlight, even for a short period, can increase the cartridge temp considerably, and a hot pistol will develop different pressures than when cold. Barometric pressure and humidity have a great affect, as well. When the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.
+1
Quote from: DM1906 on May 28 2013 09:59:46 AM MDTWhen the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.
Excellent point. On top of that, any variation is exponentially exaggerated when rounds are on the ragged edge to begin with. All of a sudden chamber dimensions become more relevant between different platforms. A little difference in powder charge bocomes the difference between a light pressure sign and a major pressure sign. The odd occurance of bullet setback becomes a much greater issue. On and on.
Not to mention that there are deviances in loading. I know that at Lake City and other big mfg's rounds are weighed before and after charging with powder, and then random samples are still QC'd. If more than a certain number are outside qc the whole lot is scrapped.
I appreciate what Underwood does for 10mm, but in reality I doubt he can afford to pull down an entire run if there is a large QC issue, and I doubt each round is weighed before and after charging.
It creates windows that when loading in mass ensure that will eventually let an overcharge slip through.
Most of us here get that and accept the risk. Not sure everyone that buys does understand that.
I ran 100 rds of these nickel plated Underwood 200 gr. xtp's through my DW-Cbob and NH-Falcon today with no issues. The cases all looked great. I just don't get what all the hype is over recoil and the 10mm's, it was nice. I guess after shooting 3 and 4" barreled 44 mags with full power ammo though the 10's no big deal. ;D
Good report. Thanks!
Quote from: Intercooler on May 26 2013 08:54:27 PM MDT
I pick up a Double Tap Nickel case every 2-3 months at the range. Oddly, none have ever contained a primer :o
DoubleTaps (alternating 150gr and 180gr in all mags) are my carry rounds, and are also mostly what I shoot lately at the range. I've never seen a missing primer in those casings. I haven't ever shot any DT 135gr, though. I HAVE seen missing primers (multiple times) in Underwood (either 155gr and/or 180gr ... I don't know which, because I alternate them in all mags, and the casings look the same).
Next time I find a few I will throw up a picture with the measurements.