BRT OPTIMUM Barrels

[Clint]

Sure,


The ballistics were touched on previously.


The prototype 9" made 2580 fps on M193 and M855 with standard rifling.

The velocity should be higher with the hybrid poly rifling.

The 6.75" should be above 2300 fps.

These are both quite useful with Federal Fusion ammo, which performs nicely above 1700 fps.

As part of our normal first article inspection, we'll be chronographing the production barrels and adding the results to the product descriptions.

The 9" PDW is light recoiling and easily stomps any 9mm or 300 BLK for flat trajectory within 200 yards.


We haven't done statistical reliability testing, per se.

However, using our mathematical gas drive model that was also the basis of the EXT gas system, we calculated the proper relationship between the 9" barrel and PDW gas system, as well as the required port size.

We nailed the port size on the first try and it operates exactly as expected with nice 3:30-4:00 ejection with all tested ammo.

When the timing ratios and gas drive are properly setup, maximum reliability is the natural result.

This is the essence of OPTIMUM gas drive.

Clint, can you comment on the ballistics and reliability of the 9” and 6.75” offerings?

[BufordTJustice]

I've only shot one rifle like that. It was a 3gunner's rifle set up around a specific load on the ragged edge of function. And in accordance with Murphy, it malfunctioned during a big match he was doing well in. I'm actually about to throw a SF muzzle brake on my BRT Optimum build for the incoming SOCOM suppressor, looking forward to it.

Well this one worked with a limp wrist and no shoulder purchase.


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[BufordTJustice]

This is a good example of the synergy between a very effective brake and the OPTIMUM gas system.

Unlike many over tuned 3 gun setups, OPTIMUM barrels maintain full reliability margin, while being extremely smooth.

Good things happen when the AR system operates at optimal timing, rather than fighting itself.

Yeah, it was actually nearly identical to my buddy's 3-gun rig the uses a much heavier Stretch-16 barrel that also uses a longer-than-mid gas barrel.


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[AndyLate]

I just got home from zeroing and shooting the 16" Light Optimum upper I assembled last night. Details are in an earlier post to this thread, but it has an A2 flash hider and A5 system with standard/A5H2 buffer.

It ran perfectly with my mild 55 gr handloads and Hornady Frontier M193 and 75 gr HP 5.56 loads. The reliability and soft shooting were anticipated when I picked that barrel.

What I was not expecting is how "flat" it shoots. I was zeroing the 1-4 accupower with a very light hold and the gun seemed to move less than my 20" Faxon Gunner on the same lower, didn't "bounce" on the rest at all.

I was also suprised at how well it shot, given the modest magnification even at 50 m.

I'm definitely looking forward to shooting this upper some more.

Andy

P.S. Neither my shooting or camera skills resemble Stickman's, but here is a quick snap.

[everready73]

I just got home from zeroing and shooting the 16" Light Optimum upper I assembled last night. Details are in an earlier post to this thread, but it has an A2 flash hider and A5 system with standard/A5H2 buffer.

It ran perfectly with my mild 55 gr handloads and Hornady Frontier M193 and 75 gr HP 5.56 loads. The reliability and soft shooting were anticipated when I picked that barrel.

What I was not expecting is how "flat" it shoots. I was zeroing the 1-4 accupower with a very light hold and the gun seemed to move less than my 20" Faxon Gunner on the same lower, didn't "bounce" on the rest at all.

I was also suprised at how well it shot, given the modest magnification even at 50 m.

I'm definitely looking forward to shooting this upper some more.

Andy

P.S. Neither my shooting or camera skills resemble Stickman's, but here is a quick snap.

Looks like a nice setup. Would be interested in some accuracy results if you have time once you shoot some more.

Out of curiosity what spring are you running with the A5 system. Sprinco green, tubbs, Colt rifle ? I have been doing a lot of reading on the right spring and still can't figure out what I want to run

[opngrnd]

Looks like a nice setup. Would be interested in some accuracy results if you have time once you shoot some more.

Out of curiosity what spring are you running with the A5 system. Sprinco green, tubbs, Colt rifle ? I have been doing a lot of reading on the right spring and still can't figure out what I want to run

Perhaps start with the Colt spring/A5H2 and make adjustments as needed from there.

[AndyLate]

Looks like a nice setup. Would be interested in some accuracy results if you have time once you shoot some more.

Out of curiosity what spring are you running with the A5 system. Sprinco green, tubbs, Colt rifle ? I have been doing a lot of reading on the right spring and still can't figure out what I want to run

Thanks!

I am intererested too. Whenever I get time, I will borrow the 4-12 VXII that's mounted on my 20" rifle and do some serious shooting. The accupower is a nice optic, but I need more scope to shoot groups at 100 yards/meters or farther.

I'm running a standard BCM rifle spring in the A5.

It's probably heresy, but I don't plan on trying to tune it.

I'm building it as a second upper for my 20" rifle and envision it as a general purpose carbine. Perfection can be the enemy of good, and it's pretty good now.

Andy

[opngrnd]

Clint-Do you think the 5.56 SPR barrel gives up anything to the 223 Wylde barrel in terms of accuracy? My buddy's 5.56 barrel arrived and it looks AWESOME. Intended ammo is BH 5.56 TMK or TMK reloads. I'm looking forward to running it against the MPR barrel.

[Clint]

No, the 556 MOD0 chamber is similar to the Wylde.

It should love the heavy projectiles, especially when reloaded.

Clint-Do you think the 5.56 SPR barrel gives up anything to the 223 Wylde barrel in terms of accuracy? My buddy's 5.56 barrel arrived and it looks AWESOME. Intended ammo is BH 5.56 TMK or TMK reloads. I'm looking forward to running it against the MPR barrel.

[Clint]

The green is a good spring, but requires a little more gas drive to fully compress and increases bolt closing speed too.

The A5H2 with standard rifle spring is the baseline that all our barrels are setup for.

We also verify function with a straight up CAR system just to cover all the bases.

Everyone is certainly free to play around with combinations other than the A5H2/rifle, but in general there's no need and no real gains to be had with an OPTIMUM barrel.

Out of curiosity what spring are you running with the A5 system. Sprinco green, tubbs, Colt rifle ? I have been doing a lot of reading on the right spring and still can't figure out what I want to run

Perhaps start with the Colt spring/A5H2 and make adjustments as needed from there.