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Columbia Falls, Montana – With the release of its new patent-pending Caliber Matched Gas System (CAMGAS) barrels, PROOF Research has eliminated the issues traditionally associated with building 6.5mm and .260 rifles on 308AR/AR-10 platforms. Until now, AR-variant shooters looking for ballistic advantages from either of these calibers were faced with excessive bore pressures that necessitated makeshift solutions such as clipping buffer springs, adjusting buffer weights, and/or relying on adjustable gas blocks, to keep their rifles functioning properly.
PROOF’s R&D team has solved the overpressure issue with gas systems tuned specifically to the cartridge/barrel-length combination. “By moving the gas port, the pressure in the bore is given time to reduce to that comparable of a .308 Winchester with a rifle-length gas system, which is what the 308AR/AR-10 system was designed around,” said Greg Hamilton, PROOF’s research-and-development weapons specialist who’s also a 3-Gun and PRS competitive shooter. “The recoil impulse is noticeably smoother, which helps keep you on target while taking advantage of a more efficient projectile. Case extraction is also easier, with less case-head smearing, so the brass is in much better condition for reloading.”
In recent years, 6.5mm Creedmoor and .260 Remington have become increasingly popular in long-range shooting competitions. The .260, in particular, represents an outstanding caliber for a military counter-sniper role—out to roughly 1,000 meters—in smaller- to mid-sized weapon systems. It offers exceptional accuracy and superior ballistics over the ubiquitous .308 while dishing out substantially less recoil and enough energy to make it a legitimate contender for military and law enforcement applications.
“I’ve been using prototype CAMGAS barrels, in both .260 and 6.5 Creedmoor, in competition for almost a year with excellent results,” Hamilton explained. “Both rifles ran flawlessly through high-round, fast-cadence stages, firing hundreds of rounds with 100 percent reliability and zero maintenance or cleaning. From recoil to reliability, every aspect of performance was improved compared to the typical un-tuned barrel.”
PROOF Research currently offers Caliber Matched Gas System barrels chambered for 6.5mm Creedmoor and .260 Remington in three separate lengths: 20, 22, and 24 inches. Every CAMGAS barrel comes standard with an easy to install custom-length gas tube. To learn more about customizing your larger-frame AR with a smoother-shooting PROOF Caliber Matched Gas System barrel, visit proofresearch.com or contact PROOF Research at [email protected] or (406) 756-9290.
I have 10-15 different AR10 rifles in the past 15 years.
My most accurate Ar10 platform is a Larue PradatOBR rifle with a 20" Proof 6.5 CM with the +2 barrel installed. (I'm not a fan of Larue for accuracy!)
I'm running the 140 Amax bullets at 2750 fps and I'm getting 1/2 MOA out to 600m. Most guys will cherry pick a 1/2 MOA group but this barrel just does it!
It also balances much better than the 18": factory barrel.
My most accurate Ar10 platform is a Larue PradatOBR rifle with a 20" Proof 6.5 CM with the +2 barrel installed. (I'm not a fan of Larue for accuracy!)
I'm running the 140 Amax bullets at 2750 fps and I'm getting 1/2 MOA out to 600m. Most guys will cherry pick a 1/2 MOA group but this barrel just does it!
It also balances much better than the 18": factory barrel.
Wow, i dont know mucb about gas guns but 2750 seems fast for 140s! Thats awesome
Ok....So I had to go check my data book.
I'm at 2700 fps running the 140 amax and H4350 in a Hornady case.
Its a bit hard on the cases but I have over 1000 once fired to cycle from and a few sets of new gas rings.
I have aprox 150 rounds down the barrel so it will be interesting how it holds up.
The other day I shot a 5 shot group at 650y that I could cover with a dollar bill. (the wind was from 9-12 mph and switching from 2-7 o'clock)
I'm at 2700 fps running the 140 amax and H4350 in a Hornady case.
Its a bit hard on the cases but I have over 1000 once fired to cycle from and a few sets of new gas rings.
I have aprox 150 rounds down the barrel so it will be interesting how it holds up.
The other day I shot a 5 shot group at 650y that I could cover with a dollar bill. (the wind was from 9-12 mph and switching from 2-7 o'clock)
I've seen reports of at least one that short strokes.
My 24" Criterion runs just fine with standard rifle gas. If I went 26" I might consider +2" gas but I don't think I would want to try it on a barrel less than 24".
A good adjustable gas block probably does a lot more for you.
My 24" Criterion runs just fine with standard rifle gas. If I went 26" I might consider +2" gas but I don't think I would want to try it on a barrel less than 24".
A good adjustable gas block probably does a lot more for you.
Well that press release is years old. Proof was in the first group of companies to really push the extended length gas.
A gas block can help but the timing difference is what a lot of people were searching for. I have a proof CF with the extended gas, an adjustable block, JP adjustable carrier and buffer and even tuned to the edge the system STILL beats the living shit out of brass. 6.5 is a pain in the ass in a semi auto for reloaders and every little bit, like 2" added to gaslength, can help.
I have been interested in a Proof barrel for my PredatOBR for quite a while. What did you have to do to the Proof to make it work?
Nothing.
I now have a 18" .308 or 20' 6.5 CM switch barrel.
I now have a 18" .308 or 20' 6.5 CM switch barrel.
Running fine and running optimally are 2 different things. In the 10+ 6.5cm semis I've built over the past few years the first 2 had rifle gas. All custom cut rifled barrels from Bartlein, Rock and Kreiger. They ALL were tack drivers. The rifle gas, no matter what buffer or gas setting would beat the shit out of case heads and blow primers on occasion. All barrels were 22".
Since switching to +2 gas and using a properly configured JP SCS heavy and AGB my brass looks like it was fired in a bolt gun. Not a mark on the case heads.
So sure you can throw any barrel, buffer combo together and it will run..doesnt mean it's optimal
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