BRT EZTUNE Gas Tubes

AR/M4 AR Technical Discussion
1

We’ve got a few updates to our highly popular BRT EZTUNE Gas Tubes to share.

But first, a quick review of what these are.

The EZTUNE Gas Tubes are the quickest, easiest way to reduce the gas drive of any barrel.

They are especially handy when the muzzle device and or gas block is pinned to the barrel and removal of those items is not possible.

The tube has the restricted gas port formed in the tube itself and is very effective as controlling gas, whether the existing barrel has an overly large gas port or is being setup for dedicated suppressed use.

These have been out for over a year and are proven in a variety of applications.

To further simplify selection of our EZTUNE Gas Tubes for retail sales, we’ve added application specific sizes that should cover most common uses.

  1. Standard MID 14" - 16" Barrel
  2. Standard CAR 14" - 16" Barrel
  3. Standard CAR 10" - 12.5" Barrel
  4. SUPPRESSED CAR 10" - 14.5" Barrel

We’ve also added solutions for LMT monolithic small frame and large frame applications.

These barrel cartridges are particularly troublesome to address with conventional solutions, as the high rise gas block is both pressed and pinned onto the barrel.

In addition, many users run suppressors, compounding the problem.

EZTUNE Gas Tubes solve this with a fast, effective fix for this particular application.

2

Stupid question: Could this system also be a viable tool for extending the useful life of a high-mileage barrel with port erosion? For example, ten-inchers are widely reputed to need rebarreling at half the life of a 14.5 M4 IIRC, so I’m wondering if replacement tubes might be a viable crutch until it’s opened up far enough to tap and mount a new port in the barrel.

3

I installed a custom tune gas port on a 16" carbine with excellent results. The tubes and also having pre-configured tubes sure simplifies the process.

Has the 14.5 -16" carbine market fallen off enough that offering an application specific tube for them isn’t viable?

I’m thinking a bunch of PSA and Ruger pistol owners should be knocking on your door…

Andy

P.S. I’m not dissing PSA owners - the 16" carbine upper I installed the gas port on is from PSA and being overgassed was my only beef with it.

4

Im using one on my PSA 10.5 for the last 6 months; and its eating everything I have offered it!

Thanks Clint!

5

A barrel’s throat will be gone WAY before any port erosion would be an issue. I’m really interested in these tubes though. I just haven’t wrenched on any guns for a while…

6

For sure.

They can drop the gas drive back down to factory.

7

We’ll probably add that application too.

Lots of those out there and many are badly overgassed.

8

I own two of these and they are outstanding!

9

That’s good. One of these are headed your way.

10

Recently ordered one of these to tame a hard bucking overgassed carbine with pinned FH. Looking forward to not running a ridiculously heavy H3 buffer anymore. If I recall the manufacturer stated they spec’ed their ports at .073 or something equally huge. I’m sure with some port erosion it is even larger than that now. Thanks for coming up with such a simple and easy solution!

11

.073 for a carbine gas 16’'? That is pretty huge

What size did you end up ordering? I believe you order a size or 2 smaller than what you would want at the port due to the way gas drive works. I would think .060-.062 would be around where you want to be. Betting h2 or even h will run smooth.

Let us know how it works out. I love the inserts, might be ordering a tube for my uncle’s gun

12

It is a 14.7" with pinned A2 FH. BRT recommended the .0635 gas tube. On the tubes they indicate to go up one size from the targeted barrel port size for equivalent function. I’m pretty interested to see what buffer I can run with the springco blue I have currently. I have all the different weight combos I can try. Whatever nets the best ejection and consistent lockback.

13

Yes, this is actually fairly common.

Across dozens of barrel mfgs, gas port sizes average ~15% larger (by area) than needed.

14

Clint, I’m thinking of using your has tube for a my 18" midlength Blackhole Weaponry barrel 308. The port is .081 on a .750 gas block journal, and the barrel feels very over gassed. I’ve been using an SLR adjustable gas block almost all the way locked down to tame it.

What port size gas tube would you recommend, please?

15

We don’t have quite as good data for 308 applications, but most info points towards very similar sizes to 223.

An 076 size would be a good starting point.

16

I’m thinking of using your gas tube for a my 13.7" midlength Noveske 5.56 barrel. The port is .086 on a .750 gas block journal, and the barrel is very over gassed. I’ve been using an SLR adjustable gas block almost all the way locked down to tame it. This Barrel is shooting suppressed 95% of the time.

What port size gas tube would you recommend, please?

17

Could I start smaller and then drill it larger if necessary like your gas block inserts?

18

Here’s a slightly more exotic one… Could EZTune adjust a milspec 20" rifle’s gas drive to reliably cycle with an H or H2 buffer rather than H3 or H6? Idea here is a build with M16 and M4 uppers sharing a common lower assembly, hoping to not have to remember to swap buffers as part of the switch.

19

Nah, that one’s pretty easy and our general goal is to get all uppers gassed about the same.

For a rifle length, we’d have to modify a standard tube. Just order the midlength and add a note to make it rifle.

20

What this guy said.

My question is what is the expected round count life of one of these gas tubes?

After seeing guns burn holes in the topside of the gas tube between 10k and 15k rounds with proper sized gas ports, how long will the thin wall of these gas tubes last?