BRT OPTIMUM Barrels

[AKDoug]

Thanks. Not sure if I'm going with that rail, but it's very inexpensive and a good way to test out whether I want to go this route.

[Clint]

Which suppressor are you looking to pair this with?

I'm really interested in building an SBR with a suppressor that ends up being about the same length as my 16" carbines...

[AKDoug]

Which suppressor are you looking to pair this with?

I'm new to the whole suppressor world, but right now I'm looking at the Sandman S or Sandman Ti.

The rifle I am building with your 16" MPR and covert comp comes in at roughly 18" long and 34 ounces or so, plus about 4 ounces of rail, for a total of 38 ounces. .

The 9" PDW barrel, plus Keymount + Sandman Ti equals right at 17.5" and 38 ounces. Front sight will be further back as well.. so I think it will balance great.

[1168]

I'm new to the whole suppressor world, but right now I'm looking at the Sandman S or Sandman Ti.

The rifle I am building with your 16" MPR and covert comp comes in at roughly 18" long and 34 ounces or so, plus about 4 ounces of rail, for a total of 38 ounces. .

The 9" PDW barrel, plus Keymount + Sandman Ti equals right at 17.5" and 38 ounces. Front sight will be further back as well.. so I think it will balance great.

Sandman Ti is direct thread. If your looking to use the Keymount, you want the Sandman S.

[AKDoug]

Sandman Ti is direct thread. If your looking to use the Keymount, you want the Sandman S.

Thanks. I missed that. An S is likely where I'll go. I want ease of moving from one rifle to the next quickly.

[1168]

Shot my 16” BRT light barrel today. 86 rounds Precision One 62gr 5.56, 100 rounds P One 55gr .223, 10 rounds Fusion MSR for lock back testing. Zero stoppages with H2 and Sprinco Blue. 100% lock back on empties. 75F, rainy. Recoil was noticeably more than my 14” midweight BRT, but the muzzle stayed tight to the targets hammering triples. It currently wears a FCD 1815 flash hider. Swings between targets like a light barrel should. I’m using a URX4. Very fast transitions, and very fast splits. I bet it’ll be a total pussycat on one of my A1 rifle style lowers.

This rifle is going to see a lot of use, but the 14” midweight is my favorite of the two. Might be my favorite rifle, overall. The 16” light is probably my favorite 16” rifle, so far. We’ll see if thats still true in a few thousand. I just need a flashlight for it now.

[opngrnd]

The 14" barrel made me a believer in the P&W. If I didn't already have the 16" LW, I'd build a second 14.5" P&W if there was a LW 14.5". I never thought it'd matter, but I really notice and appreciate the shorter overall length. I do wonder if a LW 14.5" would feel like a pogo stick, though. I still need to get my pistol build done.

[1168]

The 14" barrel made me a believer in the P&W. If I didn't already have the 16" LW, I'd build a second 14.5" P&W if there was a LW 14.5". I never thought it'd matter, but I really notice and appreciate the shorter overall length. I do wonder if a LW 14.5" would feel like a pogo stick, though. I still need to get my pistol build done.

I feel like the14” MPR is really at home on a registered SBR with an A2 length flash suppressor, like the 6315. Its pretty much the shortest barrel that is safe on a 13” URX4.

[Clint]

Curious whether or not there's anything you can share that quantifies your claim that the gas system lengths and port sizes are "optimized" for each barrel length? Very interesting product line that I feel may address what I think is the root of of all evil on the M4 platform (gas drive). Maybe something worth fiddle ****ing around with if they were so inclined.

We start with very specific relationships for the gas system and barrel length to set the overall timing.

The gas system length also determines the available Gas Drive for that barrel length.

The initial gas port size is calculated from the numerical models to produce the total Gas Drive, both suppressed and un-suppressed.

By the way, the proper Gas Drive for all possible configurations varies by only +/- 10%.

The final gas port size is verified through extensive testing using a range of buffer weights and ammo in a variety of conditions and situations.


Post #7 hits the highlights of the results.

Barrel and Gas System Lengths Explained
16" EXT - The obvious general purpose length that needs no further explanation.
The EXT gas system certainly deserves some attention.
The Mid length gas system replicates the same "Power Time" as a 20" Rifle when used on a 16" barrel.
At first glance, this seems to be the correct approach, but duplicating one parameter at the expense of others leaves much to be desired.

A better approach is to scale the relevant timing parameters to keep everything in proportion.
Using this methodology, we developed the EXT gas system to be an OPTIMUM match for 16" barrels.
The EXT length is longer than Mid length but shorter than Rifle length.
This results in the widest operational envelope and the highest reliability possible.

9.0" PDW - A BRT exclusive that smashes the conventional wisdom of a 10.5" minimum length for "serious use".
That conventional wisdom is true, but based on a Carbine length gas system.
We created the PDW length gas system to handle a range of very short barrels and alternative calibers by splitting the difference between existing Carbine and Pistol lengths.
A 9" barrel and the PDW gas system are a perfect match in 5.56/.223.

One can see the results of these proportions when viewing the whole family together.

[WEK207]

Well,

I finally took the plunge. I ordered the SPR barrel with a pinned gas block. I also ordered a Sons of Liberty NOX to pair with the barrel.

I'm very excited to get this build underway.

Still waiting on my barrel to ship.

In the meantime, the SOLGW NOX arrived. I didn't realize the ports weren't neutral and are timed for a righty so it will be going back. Instead, I ordered a Forward Controls 6310. I've been very happy with Roger's parts and flash hiders and I have no doubt this will be just as good. I ordered at 6:00 this morning and had tracking a bit over 3 hours later.