Thinking about ordering this:
http://www.rmwxtreme.com/#top
Should I do the 16" barrel or a pistol length? He offers 8 to 16 inch barrels. I probably would do the Sig brace if shorter than 16"
Opinions desired, but I am not real interested in MechTech or Just right carbine as I am not a Glock Guy. Glock Magazines are not an advantage over the 30 round grease gun mags Ron offers.
All my rifles are 20" barrels. (one AR .223, one .308 Remington 700)
I think you receive diminishing return for anything more than 10"-11".
I would either do a 10.5" pistol or 10.5" barrel with a permanent 6" muzzle attachment for a carbine.
Wrong!!You have to start thinking carbine or rifle powders when loading instead of pistol powders. I found 2400 to be a great powder for my 16" M-T and I'm looking at some other slower powders to compliment the longer barrel of my M-T.
Doug
Quote from: ShadeTreeVTX on January 05 2015 03:27:29 PM MST
Wrong!!You have to start thinking carbine or rifle powders when loading instead of pistol powders. I found 2400 to be a great powder for my 16" M-T and I'm looking at some other slower powders to compliment the longer barrel of my M-T.
Doug
Yes, if you reload.
If your a shooter not a collector - for 10mm - its almost a must - start adding up the price of commercial amo and if your a serious 10mm shooter - you'll have at least a single stage on your bench.
Doug
Quote from: ShadeTreeVTX on January 05 2015 03:27:29 PM MST
Wrong!!You have to start thinking carbine or rifle powders when loading instead of pistol powders. I found 2400 to be a great powder for my 16" M-T and I'm looking at some other slower powders to compliment the longer barrel of my M-T.
Doug
Ummm....
Several studies have shown that with rare exception, the best powder for a given cartridge/bullet weight at a given barrel length will be the best powder for that cartridge for all barrel lengths, speaking to velocity.
Accuracy may be a different story.
There was an article in, I think, Precision Shooting many years ago where the author empirically tested this across a bunch of calibers. He went the other way, starting with long barrels, developing a max velocity load, then shortening the barrel and working up a new max velocity load.
In every case he found the same thing. The best velocity load in long barrels was also the best load in short barrels for a given bullet weight.
OP...
You may want to review the Ballistics by the Inch data:
http://www.ballisticsbytheinch.com/10mm.html
For 170 grain bullets and up, 14-15" is the sweet spot for 10mm. Lighter bullets appear to benefit a bit more from an extra few inches beyond that. Since you plan to use it like a rifle, I would get the 16" barrel, rather than mess with the admittedly cool sig brace. The velocity they show lost to 'coast' with heavy bullets in these barrels really amounts to little more than statistical error.
Thanks now I want an ar pistol in a 10mm.
Quote from: sqlbullet on January 06 2015 01:49:52 PM MST
Quote from: ShadeTreeVTX on January 05 2015 03:27:29 PM MST
Wrong!!You have to start thinking carbine or rifle powders when loading instead of pistol powders. I found 2400 to be a great powder for my 16" M-T and I'm looking at some other slower powders to compliment the longer barrel of my M-T.
Doug
Ummm....
Several studies have shown that with rare exception, the best powder for a given cartridge/bullet weight at a given barrel length will be the best powder for that cartridge for all barrel lengths, speaking to velocity.
Accuracy may be a different story.
There was an article in, I think, Precision Shooting many years ago where the author empirically tested this across a bunch of calibers. He went the other way, starting with long barrels, developing a max velocity load, then shortening the barrel and working up a new max velocity load.
In every case he found the same thing. The best velocity load in long barrels was also the best load in short barrels for a given bullet weight.
OP...
You may want to review the Ballistics by the Inch data:
http://www.ballisticsbytheinch.com/10mm.html
For 170 grain bullets and up, 14-15" is the sweet spot for 10mm. Lighter bullets appear to benefit a bit more from an extra few inches beyond that. Since you plan to use it like a rifle, I would get the 16" barrel, rather than mess with the admittedly cool sig brace. The velocity they show lost to 'coast' with heavy bullets in these barrels really amounts to little more than statistical error.
I read this post when you posted it a while ago. And I agree with the article completely. But I think the context is rifle. Like the difference between 20 inches and 26 inch barrels.
I do think that this will breakdown at some point, like is that 3.6 inch compact pistol as accurate as a .26 inch rifle.
I guess I was thinking of another article about the myth that longer barrels are more accurate. Not the velocity one referenced above.
There are some other factors. Like 16" barrel is classified as a rifle.
Less is a pistol. And I don't pretend to understand the process of licensing a short barrel rifle. (Sounds complicated and long cause the ATF is involved)
Depending on where you live, it can be easy or hard. Where I live, it is pretty trivial. The process is long though, as at present it is taking about 18 months for the ATF to approve suppressor and SBR requests.
Most guys that are set on having a true SBR build the gun up as a pistol, submit the paperwork and then put a stock on it when the paperwork finally clears. The advent of the sig arm brace and ATF ruling that it doesn't constitute a stock even when used as one largely subverts the whole process in my mind. Why pay 200 and wait 18 months just for a different piece of nylon that functions the same as the sig brace?
As far as barrel length and either accuracy or powder burn rate/velocity, there is no point at which, in testing, shorter barrels have been at any disadvantage other than velocity drop due to less time under the accelerating pressure. Pick the shortest barrel that will meet your velocity objectives.
Taken from page 169 "The Complete Reloading Manual for the T/C Contender"
PLEASE NOTE: "The following loads are for the Contender pistol only."
Use the below information at your own risk. This information is provided for informational purposes only. This is Published Load data circa 1991.
Test Specifications:
Firearm:T/C Contender
Bbl. Length / Twist: 14" / 1-16"Cases: Norma
Trim-to Length: .987
Primers: Federal 150
Sierra Bullets Used
150gr JHP
Powder 1300 1400 1450 1500 1550 1600
No.7 11.6 12.2 12.5 12.8 13.1
Blue Dot 10.9 11.5 11.8 12.1 12.3
HS7 11.7 12.5 12.9 13.2
No.9 14.5 14.9 15.3 15.7 16.0
180gr JHP
Powder 1100 1200 1250 1300 1350 1400
No.7 9.8 10.6 11.0 11.3
Blue Dot 9.0 9.4 9.6 9.8 10.0 10.3
HS7 9.8 10.6 11.0
No.9 12.5 12.9 13.2 13.5
2400 12.3 13.1 13.5 13.9 190gr FPJ
Powder 1000 1100 1200 1250 1300 1350
No.7 9.2 9.8 10.5
Blue Dot 8.6 9.2 9.8 10.1 10.4
HS7 9.5 10.1 10.7
No.9 12.5 13.0 13.4 13.7
2400 12.0 12.7 13.3 13.6 14.0 --Tables cleaned up a bit
150 gr JHP
| Powder | 1300 | 1400 | 1450 | 1500 | 1550 | 1600 |
| No.7 | 11.6 | 12.2 | 12.5 | 12.8 | 13.1 | |
| Blue Dot | 10.9 | 11.5 | 11.8 | 12.1 | 12.3 | |
| HS7 | 11.7 | 12.5 | 12.9 | 13.2 | | |
| No.9 | 14.5 | 14.9 | 15.3 | 15.7 | 16 | |
180 gr JHP
| Powder | 1100 | 1200 | 1250 | 1300 | 1350 | 1400 |
| No.7 | 9.8 | 10.6 | 11 | 11.3 | | |
| Blue Dot | 9 | 9.4 | 9.6 | 9.8 | 10 | 10.3 |
| HS7 | 9.8 | 10.6 | 11 | | | |
| No.9 | 12.5 | 12.9 | 13.2 | 13.5 | | |
| 2400 | | 12.3 | 13.1 | 13.5 | 13.9 | 13.9 |
190 gr JHP
| Powder | 1000 | 1100 | 1200 | 1250 | 1300 | 1350 |
| No.7 | 9.2 | 9.8 | 10.5 | | | |
| Blue Dot | 8.6 | 9.2 | 9.8 | 10.1 | 10.4 | |
| HS7 | 9.5 | 10.1 | 10.7 | | | |
| No.9 | 12.5 | 13 | 13.4 | 13.7 | | |
| 2400 | | 12 | 12.7 | 13.3 | 13.6 | 14 |
Please Note: the Data as noted is from 1991 and some of the powders have changed formulary in that time. please Cross Reference to other published data, and always work up to those max loadings. It has been pointed out that some of the data has changed.
Quote from: sstewart on January 04 2015 06:57:56 PM MST
Thinking about ordering this:
http://www.rmwxtreme.com/#top
Should I do the 16" barrel or a pistol length? He offers 8 to 16 inch barrels. I probably would do the Sig brace if shorter than 16"
Opinions desired, but I am not real interested in MechTech or Just right carbine as I am not a Glock Guy. Glock Magazines are not an advantage over the 30 round grease gun mags Ron offers.
All my rifles are 20" barrels. (one AR .223, one .308 Remington 700)
That site seems rather sparse. What mags does that 10mm upper use? I assume it comes with a bolt, but what else? Does it even come with a 10mm magazine? Block for mag well.
How to order - email him?
Price is high, but may be worth it depending on extras.
Thanks!
P
Thanks for posting up this data Pinscrews.
I have a couple of comments about the data though.
First, anyone thinking of using this data should be warned that the data for 2400 is well over the Alliant published max loads for 10mm in those weights. Alliant lists 12.9 grains as max in 180 grain, and 12.5 grains as max in 190 grain.
Second, when looking at the data, it also stopped well short of max book loads for AA #9 with 190 gr. Accurate lists 14.2 grains as a max load for that bullet weight. I don't know if that means that is just where the authors stopped testing, or if they encountered pressure signs or velocity irregularities, or other issues that gave them pause. Extrapolation would put the AA #9 a little ahead of 2400 if they had loaded to 14.2 grains.
Third, the velocities listed with AA#9 in 180 grain are low compared to other sources. In fact, these velocities are more in line with a 8" test barrel than a 14" barrel. Again, this could be evidence that they were experiencing velocity irregularities in testing #9 in their test gun.
Doug, you have the gun. It would be great if you could test some loads and post up the raw data of the results in both your M/T 16" and a standard length barrel.
Quote from: Pablo on January 13 2015 05:43:10 AM MST
Quote from: sstewart on January 04 2015 06:57:56 PM MST
Thinking about ordering this:
http://www.rmwxtreme.com/#top
Should I do the 16" barrel or a pistol length? He offers 8 to 16 inch barrels. I probably would do the Sig brace if shorter than 16"
Opinions desired, but I am not real interested in MechTech or Just right carbine as I am not a Glock Guy. Glock Magazines are not an advantage over the 30 round grease gun mags Ron offers.
All my rifles are 20" barrels. (one AR .223, one .308 Remington 700)
That site seems rather sparse. What mags does that 10mm upper use? I assume it comes with a bolt, but what else? Does it even come with a 10mm magazine? Block for mag well.
How to order - email him?
Price is high, but may be worth it depending on extras.
Thanks!
P
Yes every thing is by email. Definitely not a pushy sales type. His reputation seems good.
I am looking at an assemble it your self deal between 1,110 to 1,250. Upper is complete. lower has to be put together.
He uses grease gun mags - 30 round capacity (this actually is a good thing) most pistol caliber ARs use this type of magazine
YHM hand-guard is a $100 upgrade (in above amount)
The beauty of RMW's gun is that it is mostly standard AR parts, triggers, pins, etc and that it is gas impingement instead of blow back
Thanks - duh on my part, you did say grease gun mags in your OP. I agree that's a good thing. Slight adjustment and they hold 10mm just fine - over 30 rounds!!
And bonus you answered my next question - gas impingement. 10mm does fine with a gas system from what I've seen.
I agree that 14-15" is a sweet spot with most powders and 16" will be great.
I have emailed him. I see he sells GG lowers. SweeT!!!
Thanks man!
Quote from: sqlbullet on January 13 2015 08:41:59 AM MST
Thanks for posting up this data Pinscrews.
I have a couple of comments about the data though.
First, anyone thinking of using this data should be warned that the data for 2400 is well over the Alliant published max loads for 10mm in those weights. Alliant lists 12.9 grains as max in 180 grain, and 12.5 grains as max in 190 grain.
Second, when looking at the data, it also stopped well short of max book loads for AA #9 with 190 gr. Accurate lists 14.2 grains as a max load for that bullet weight. I don't know if that means that is just where the authors stopped testing, or if they encountered pressure signs or velocity irregularities, or other issues that gave them pause. Extrapolation would put the AA #9 a little ahead of 2400 if they had loaded to 14.2 grains.
Third, the velocities listed with AA#9 in 180 grain are low compared to other sources. In fact, these velocities are more in line with a 8" test barrel than a 14" barrel. Again, this could be evidence that they were experiencing velocity irregularities in testing #9 in their test gun.
Doug, you have the gun. It would be great if you could test some loads and post up the raw data of the results in both your M/T 16" and a standard length barrel.
Yes, I read an old article about the TC Contender barrels in 10 mm. Certain powders reached Peak Pressure within 5-6 inches of ignition, thereafter losing velocity. You are correct also regarding the load data, and I will add an addendum to the post. That Data is from the early 90's and some of those powders have changed formulary, in other cases, manufacturers have cut back on powder weights due, it is beleived, to unsupported chambers and the brass not being able to live up to its true SAAMI pressure ratings.
Btw, having problems getting the data to line up correctly, 2400 should line up to include the fastest velocity with a blank being at the beginning of the velocity rows.
Quote from: Pinsnscrews on January 14 2015 12:17:47 AM MST
Btw, having problems getting the data to line up correctly, 2400 should line up to include the fastest velocity with a blank being at the beginning of the velocity rows.
I edited the tables.
I don't have a chrono - and the 30 yard indoor range I shoot at won't let me set one up there - so I haven't bought one. The outdoor range I would like to go to - is 40+ miles away and the owner is a royal prick! - at least he was 3 years ago - word has it things have changed - I'll make a trip out in the spring to check it out, if so than a chrono will be a part of my inventory.
Set up right For the M-T - since it's a blow back set up - I have to find the that fine edge on the slower powers to get maximum fps and accuracy.
Shooting Georgia Arms 180 +p - the brass barley makes it 8-10" when ejected - tells me I have a ways to go - I also have some designs to spring load up the bolt longer before it moves to eject giving the slower powders a better change to work in the 16" barrel, it might end up limiting me to what the brass and primers can handle.
I know the 13.2gr of 2400 out of the G20 6.6" barrel left some of the powder unburned but with a real healthy recoil - the M-T none and with a healthy recoil also, the brass and primer where fine ( I ended up putting a rubber recoil pad on the M-T from shooting those rounds ) would love to be able to chrono those rounds. Thats why I looking at ##9 and Steel powders for it.
Doug
There is a chrono that attaches to the end of the barrel. It is a tad pricey, and they do claim a higher accuracy over other styles of chronos.
MagnetoSpeed V3 Ballistic Chrono
http://www.midwayusa.com/product/628777/magnetospeed-v3-ballistic-chronograph
My 10mm 11" barrel SBR is under construction. He cashed my check last week. All rail up top (only) with the midlength guard just short of the end of the barrel. Similar to the .45ACP shown in his Complete DI 45 ACP package photo, only a rifle, 10mm, in black and 11",
I have not decided which sights I will mount on it, or just an optic.
The whole shooting match is $1100. I tend to think that's a good deal as there isn't much to compare to. I guess it's cool the lower could be used with other calibers.
Very cool. I'll be tuned in for your range report.
My 11" RMW 10mm upper showed up yesterday. It's very, very nice.
Nice. Do you have lower also ?
Quote from: sstewart on February 16 2015 02:00:20 PM MST
Nice. Do you have lower also ?
Lower should be delivered to the FFL tomorrow.
I got the upper, bolt carrier, bolt, lower kit, stock, and a grease gun mag.
Wow.
I've learned a LOT in the last month+. Not only do I love RMW Xtreme even more, I started my own build thread:
http://10mm-firearms.com/10mm-rifles/rmw-extreme-build-it-has-begun/
OK consider me weird. I do not like 16 inch barrels, I prefer a 20", or even better, a 24". I just seem to shoot a lot better with longer barrels. One of the reasons I spent the big bucks on a Fusion Firearms Long slide.
So then what do I do. Order a MechTech conversion with a puny 16" barrel. Well, it still beats my 6" longslide.
I have little use for a long barrel in a pistol caliber, even 10mm. but a 16" with a 6" can would give a good balanced feel like a longer barrel and make it pleasant to shoot indoors.
Sent from my Nexus 5 using Forum Fiend v1.2.5.
Quote from: gandog56 on February 25 2015 08:50:11 AM MST
OK consider me weird. I do not like 16 inch barrels, I porefer a 20", or even better, a 24". I just seem to shoot a lot better with lnger barrels. One of the reasons I spent the big bucks on a Fusion Firearms Long slide.
He does offer up to 18.3 I think.
Quote from: sstewart on February 25 2015 02:51:14 PM MST
Quote from: gandog56 on February 25 2015 08:50:11 AM MST
OK consider me weird. I do not like 16 inch barrels, I porefer a 20", or even better, a 24". I just seem to shoot a lot better with lnger barrels. One of the reasons I spent the big bucks on a Fusion Firearms Long slide.
He does offer up to 18.3 I think.
QuoteAll CCU's have a 16" barrel. The basic unit is NOT a firearm and needs no special licensing to purchase! What do you need? You need a Glock or 1911 pistol. What do you need to do? Field strip your pistol.
Nope. This is an AR. With special grease gun magazines with an AR type lower because it is a pistol caliber. Normal gas impingement AR stuff.
How do the 10mm offerings from RMW and Thureon compare?
No experience with Thureon. RMW is an AR platform. It is gas not blow back.
Therefore the parts are more standard to AR like the lower parts kit. Triggers, stocks etc.
Quote from: sstewart on April 02 2015 02:51:59 PM MDT
No experience with Thureon. RMW is an AR platform. It is gas not blow back.
Therefore the parts are more standard to AR like the lower parts kit. Triggers, stocks etc.
I see, that makes sense. I just briefly looked at the Thureon online earlier today. I emailed them to check on pricing but havent heard anything yet.
Hopefully Pablo will report his shooting experiences soon. He had some magazine issues which RMW resolved.
RMWextreme work is superb. But you assemble the lower. Pretty easy. The upper is very nice. The drawback? GG magazine adaptation. I've had issues. ....
These issues seem fixed when I dry feed the gun........dry cycle.........I will be firing it this Saturday.
The magazines are not uniform to start, but you can improve them, it just takes a little work. When I am complete and have time I will post details. Maybe in a separate thread.
(http://pws.cablespeed.com/~pablomail//ARPistol1.JPG)
Ron Williams of RMW built me a DDLES AR/Glock mag lower and a 10mm 16" upper in December, 2013. It has ran great. For Christmas of 2014 I had him build me a .45acp 16" upper for the same lower. It too runs great.
With the Glock lower I can use any G20 or 21 magazines. I also have several of the KCI Korean 26 round .45acp mags. I slightly modified 2 of these by bending the feed lips in slightly and use them with 10mm.
Here is the 10mm;
(http://i3.photobucket.com/albums/y95/mtpys/Guns/imagejpg2.jpg) (http://s3.photobucket.com/user/mtpys/media/Guns/imagejpg2.jpg.html)
I have to say, if you don't want to battle magazine issues, stick with Glock. BUT if you want more than 30 rounds, you will do mighty battles with grease gun magazines......blasting 33 HOT 10mm rounds...it will take awhile to wipe that smile off.
Quote from: Pablo on May 22 2015 10:54:24 PM MDT
I have to say, if you don't want to battle magazine issues, stick with Glock. BUT if you want more than 30 rounds, you will do mighty battles with grease gun magazines......blasting 33 HOT 10mm rounds...it will take awhile to wipe that smile off.
Today I was prepping 307 10mm cases before I dunk them in the wet rotary tumbler. It's just too easy running up big ammo amounts with a 10 mm carbine!