BRT custom tune gas port vs heavier buffer

[LMT/556]

Installed a BRT port in a Centurion gas block with an oversized gas block port hole. Worked fine at first until pressure pushed the insert up into the gas tube creating a short stroke situation. Be sure you don't induce a point of failure, including cold temp operation.

[Clint]

Installed a BRT port in a Centurion gas block with an oversized gas block port hole. Worked fine at first until pressure pushed the insert up into the gas tube creating a short stroke situation. Be sure you don't induce a point of failure, including cold temp operation.

Let's get to the bottom of this. PM sent.

[LMT/556]

Centurion gas block port hole is larger than normal I believe, as in the supplied drill bit went right in but wasn't loose per se so I thought it would be ok. It wasn't. After a few dozen rounds the insert inserted itself into the gas tube creating a nearly shut off gas system with resulting short strokes. The account was [redacted], so look for our correspondence. I elected to just go with the Centurion setup unmodified, and now that rifle with a dragon brake and H buffer is the flattest shooting rifle we have. Rings are almost gone, but it functions great.



You offered to explore corrective options at that time, I elected to stay stock Centurion for reliability and hassle reasons and it's worked out fine.

[Bolverk93]

Clint,

What is the expected service life of your new gas tubes? Should they last the life of the barrel?

[vicious_cb]

I thought I'd post an update for the gun that inspired me to make this thread.

I got her put together on Friday and ran a few hundred rounds through it today. I've concluded that I was likely over thinking the Noveske being over gassed internet talk. I measured the gas port at .080" compared to my 14.5 BCM upper that measures .077". I'm not an engineer, and have no idea how significant that is, but it feels good shooting it with an A5H2.

Also, I'm now in love with the Precision Armament EFAB.

That is overgassed. Just because a large portion of the industry uses ≥.080" gas ports on midlengths does not make them right.

Its just like 15 years ago when the only guys doing mil-spec gas ports on their carbine barrels were Colt and LMT.

[MudPhud]

Just ordered several BRT EZTUNE gas tubes (carbine) to try out on some legacy 10.5" and 11.5" non-adjustable uppers with suppressors.

Threadjack...

Clint, what size EZTUNE gas tube (midlength) port sizes would you recommend for 14.5" midlength barrels with 50/50 suppressor use and only brass ammo?

[LMT/556]

Tube arrived and installed today. Rifle is noticeably less gassy, ejection 3/4(usually 2 o'clock before). I noticed the tube/order was switched from .073 to .076, but it functions fine, locks back last round, easier to keep on target, less impulse to dot my eye with my acog, overall a win.
Thanks for working it out...

[Clint]

Always glad to help.