BRT OPTIMUM Barrels

**Clint** · 10-24-19, 21:06

Here's a mini range report with the prototype OPTIMUM SB suppressor barrel.

The SB 11.5" uses the longer EXC gas system designed to play well with a dedicated suppressor.

The upper was tested with a Cherry Bomb and Q Thunder Chicken suppressor.

In short, it works beautifully.

It's noticeably better than the already excellent very small port carbine.

The start of cycling feels like a quick puff or pop, rather than the slower restricted gas release from a small port carbine or the massive gas attack from a standard port carbine.

There's only a hint of gas, and it never really seems to leave the ejection port.

The smoke just swirls inside the receiver when the bolt locks back.

There just a remarkable lack of drama and it works like a nicely tuned unsuppressed 16".

With an H buffer, M855 ejects to 3:00 and everything else down to steel case Wolf ejects strongly around 4:00.

Bumping up two/three steps to an A5H2 and Green spring combo, only M855 locks back while most everything else still cycles.

This is really too much spring and buffer for the low pressure 7.62 suppressor, but allows easy tuning for gassier suppressors with just a little additional buffer weight.

Fired brass is noticeably cleaner than usual when suppressed and only slightly dirtier than standard unsuppressed brass.

We're extremely pleased with these initial results.

This concept delivers everything we intended it to do.

**opngrnd** · 10-24-19, 21:45

Very nice.

**Magsz** · 10-25-19, 02:54

When can we expect em? Any new ETA based off of this testing? Excited to build mine up!

**turnburglar** · 10-25-19, 15:12

Hey Clint,

I see you offer both a light and medium taper on some of your barrel lengths (16"). Can you comment at all to the precision that each profile is achieving? Has anyone done a side by side shoot out?

I recently tested a competitors barrel (20oz / 14.5") and while it would only shoot about 1.25" groups, for a lightweight barrel it didn't have any of the myths of a wondering zero, or the groups noticeably opening like a message board would tell you. This has me wondering if thicker barrels really are better for shooting groups? I think manufacture matters a lot more.

**turnburglar** · 10-25-19, 15:12

Hey Clint,

I see you offer both a light and medium taper on some of your barrel lengths (16"). Can you comment at all to the precision that each profile is achieving? Has anyone done a side by side shoot out?

I recently tested a competitors barrel (20oz / 14.5") and while it would only shoot about 1.25" groups, for a lightweight barrel it didn't have any of the myths of a wondering zero, or the groups noticeably opening like a message board would tell you. This has me wondering if thicker barrels really are better for shooting groups? I think manufacture matters a lot more.

**Magsz** · 10-25-19, 22:06

Originally Posted by turnburglar

Hey Clint,

I see you offer both a light and medium taper on some of your barrel lengths (16"). Can you comment at all to the precision that each profile is achieving? Has anyone done a side by side shoot out?

I recently tested a competitors barrel (20oz / 14.5") and while it would only shoot about 1.25" groups, for a lightweight barrel it didn't have any of the myths of a wondering zero, or the groups noticeably opening like a message board would tell you. This has me wondering if thicker barrels really are better for shooting groups? I think manufacture matters a lot more.

Firing rate has a lot to do with that "mystery" or "myth".

Light weight barrels can produce amazing groups depending on the factors involved in how the gun is shot while its being grouped.

**1168** · 10-27-19, 10:11

You can find my results with the 16” Light in previous pages in the thread. I’m no Molon, though. It likes some factory loads better than others, with some 5rnd groups right at or under MOA, so I know the barrel itself is capable.

I did a match this weekend out to 500yds with it. With Hornady Frontier 68gr 5.56, my 5rnd groups zeroing at 300 with a front bag and 4x scope were 4-6”. Steel at 500 was easily hit, regardless of barrel temp or shooting position. Same with the smaller targets at closer range.

I‘m very happy with the practical performance. The 4x scope and my skill level is probably the limiting factor here. I’d probably get the Medium contour if my primary goal was shooting tight groups with a bipod and rear bag and a more powerful optic, but I wanted a light, handy, general purpose rifle. And its working out great for that.

4165
+200 11/10
~4365

11/12 cleaned rifle due to corrosion

11/18 +20 mixed, old duty ammo, culled from circulation
~4385

12/03 + 105 193 clone
~4490

12/07 +90 M855
~4580

12/18 + 40 mixed, old duty ammo
~4620

Cleaned, lubed

1/12 +100 55gr .223 P1
~4720

2/10 +150 55gr .223 P1
~4870

2/12 lightly lubed weapon, installed H3, Blue spring. I’m gonna use it with a can for awhile.
2/12 +40 mixed old duty ammo
~4910

2/15 +130 reloads, M855a1, Brown Tip, , M855, Frontier 68/556
~5040

2/19/20 cleaned it, relubricated. Did not scrape anything or use any solvents. There was an extravagant amount of soot from the high blowback suppressor.

2/20/20 installed PWS H4
+70rnds
~5110

2/24 installed old type CS Tubbs spring
+90rnds
~5200

03/01
Played with a variety of buffers, ammo, and a SLR Sentry 6 with a Colt spring.
+250rnds
~5450

Did a quick clean, light lube

03-13/14
+300 Winchester Ranger 55gr and Winchester 5.56 FMJ H2 Colt spring
~5750

I’m missing 300rnds of reloads marked for this rifle. So...
+300 26gr CFE 223/Hornady 62 FMJ
~6050

**turnburglar** · 10-27-19, 15:08

Yea, I use this gun for general purpose and my local black rifle competition. It has targets out to 4-500m max. Usually they opt to use smaller targets in the 250-350m range.

When I was at the range with my 14.5 LW I did the following test:

(starting with an already warm gun)

Shoot 3 rounds to verify POA/POI

Shoot a full mag (30rnds) at a rate of 1 round every 1-2 seconds

Shoot 3 more rounds to re verify POA/POI

The barrel was surprisingly consistent even after a full mag and then what ever shooting I already did during the 20 minute firing string. I was also shooting with a 4x optic though and wonder if the barrel can do better with a lot more magnification. This test that I performed may not be the most abusive, but it is very representative of how this gun actually gets used. In a stage its often to start with a full mag of hosing close targets, and then have to engage smaller targets at extended distances after a mag change. Knowing my POI has shifted dramatically is all I need I guess.