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.