BRT OPTIMUM Barrels

**CoryCop25** · 08-20-20, 11:30

Originally Posted by Ironman8

Clint is there anything you can comment on regarding the report that Sniperfrog made on your 11.5” on the last page?

I really want to try your barrel mainly due to the profile and potential better accuracy, but if it’s on the ragged edge of reliability (when unsuppressed) then I’m not sure that’s something I can accept. Any thoughts?

I’m curious to know if Sniperfrog has the CQB-s barrel. I have the CQB-s barrel and it runs fine unsuppressed with an A-5 -2 buffer but doesn’t lock back. Which is what it’s supposed to do given it’s a suppressor only barrel.

**Clint** · 08-20-20, 11:50

Sure.

Most likely SniperFrog's barrel is a CQB-S with the 50/50 porting option. Those had a slightly smaller port than current.

With the new CQB light barrels, the default gas port has been bumped up a half size for mixed use with just a buffer swap.

Our testing results mirror TJ's with full lock back on PMC Bronze with the A5H0 or CAR-H.

Buy with confidence.

One other note: Lock back testing results aren't indicative with a brand new barrel.

Gas drive increases slightly after a little break in when the sharp edges of the gas port smooth out a little and the rest of the gas system seals up.

We like to run the first range session with mostly 5.56 ammo and a lighter buffer, then proceed with any testing / tuning / reliability checks on the second outing.

Originally Posted by Ironman8

Clint is there anything you can comment on regarding the report that Sniperfrog made on your 11.5” on the last page?

I really want to try your barrel mainly due to the profile and potential better accuracy, but if it’s on the ragged edge of reliability (when unsuppressed) then I’m not sure that’s something I can accept. Any thoughts?

Originally Posted by taekwondopreacher

I went out and shot 20 more rounds through mine. The last five rounds were PMC Bronze. I shot a mag of three rapid fire with a solid hold and a mag of two with a loose hold, everything locked back. Next time I go out, I'll take an H2 buffer, brand new spring, and a few types of ammo and do a little more playing with it, but I am not able to replicate sniperfrog's results. I do know different setups behave differently.

Originally Posted by sniperfrog

I didn’t put a lot of rounds with the suppressor and H0 buffer. It cycled fine but I can feel it cycling harder.

Without the suppressor I did have the gun fail to lock back on an empty mag a few times with the lighter A5H0 buffer. The only thing that concerned me is that it was 90+ degrees that day so in colder weather I don’t know how well it will function unsuppressed.

Originally Posted by sniperfrog

I have the 11.5” cqb barrel that I bought for 50/50 suppressed use. With an A5H2 buffer, unsuppressed, it would short stroke about every 3-4 rounds using 556 ammo (M193 and Black Hills RRLP). This was in 90 degree weather. I dropped down to an A5H0 and it runs good unsuppressed. I Have a Sandman S on it now and it runs very good suppressed.
I kinda wish the gas port was slightly larger so I could just run one buffer. The Sandman doesn’t add too much back pressure so I think I would have been fine with a standard port.

**sniperfrog** · 08-20-20, 13:05

Yes, my barrel is the cqb-s which I ordered with the 50/50 porting option. That’s what Clint recommended when I told him I was going to run it unsuppressed some of the time.

I think bumping up a half size in the gas port would be perfect. I may have mine opened up slightly.

**opngrnd** · 08-20-20, 13:37

Originally Posted by Clint

Sure.

Most likely SniperFrog's barrel is a CQB-S with the 50/50 porting option. Those had a slightly smaller port than current.

With the new CQB light barrels, the default gas port has been bumped up a half size for mixed use with just a buffer swap.

Our testing results mirror TJ's with full lock back on PMC Bronze with the A5H0 or CAR-H.

Buy with confidence.

One other note: Lock back testing results aren't indicative with a brand new barrel.

Gas drive increases slightly after a little break in when the sharp edges of the gas port smooth out a little and the rest of the gas system seals up.

We like to run the first range session with mostly 5.56 ammo and a lighter buffer, then proceed with any testing / tuning / reliability checks on the second outing.

Originally Posted by sniperfrog

Yes, my barrel is the cqb-s which I ordered with the 50/50 porting option. That’s what Clint recommended when I told him I was going to run it unsuppressed some of the time.

I think bumping up a half size in the gas port would be perfect. I may have mine opened up slightly.

Now I get it. Lol. I know individual builds differ, that we are using different barrels makes it all make sense. I'm pretty happy with mine, and it's going to be a go to (along with the arriving 14" bbl) for range trips until I start practicing for service matches again.

**Clint** · 08-20-20, 14:41

We can certainly take care of that for you.

Originally Posted by sniperfrog

Yes, my barrel is the cqb-s which I ordered with the 50/50 porting option. That’s what Clint recommended when I told him I was going to run it unsuppressed some of the time.

I think bumping up a half size in the gas port would be perfect. I may have mine opened up slightly.

**sniperfrog** · 08-20-20, 14:49

Originally Posted by CoryCop25

I’m curious to know if Sniperfrog has the CQB-s barrel. I have the CQB-s barrel and it runs fine unsuppressed with an A-5 -2 buffer but doesn’t lock back. Which is what it’s supposed to do given it’s a suppressor only barrel.

Does yours have the 50/50 port option or was it ported for suppressed only?
Mine is 50/50 so the port is supposed to be about half way between full suppressed and standard. If yours is for suppressed only use than I don’t know why yours runs with an A5H2 and mine doesn’t.

Side note,
I am not blaming BRT or saying this is a bad barrel. I’m happy with the accuracy and it runs great suppressed.

**MistWolf** · 08-20-20, 16:08

Originally Posted by sniperfrog

It’s not really a home defense gun so I’m not that concerned about it. I’ll probably run it suppressed 90% of the time anyway.

You'll never shoot it unsuppressed.

**scooter22** · 08-20-20, 20:19

Originally Posted by Disciple

If you want to try a A5H4 I think you'll need to purchase that one specifically, as I think it is the only one with a drilled tungsten weight for the bias spring. When I eventually convert to A5 that's what I'll do, then use steel weights from old CAR buffers to downgrade as needed.

Can someone confirm this? I added a weight to my A5H3 to bring it to -H4. Do I need the bias spring?

**CoryCop25** · 08-20-20, 20:24

Originally Posted by sniperfrog

Does yours have the 50/50 port option or was it ported for suppressed only?
Mine is 50/50 so the port is supposed to be about half way between full suppressed and standard. If yours is for suppressed only use than I don’t know why yours runs with an A5H2 and mine doesn’t.

Side note,
I am not blaming BRT or saying this is a bad barrel. I’m happy with the accuracy and it runs great suppressed.

No, mine is full suppressed version. Runs but does not lock back. I never shoot it unsuppressed. I just tried it out for the heck of it.