Help me save some weight on a 11.5" Ballisitc advantage barrel
Saved 3oz by switching from a MI gen 2 to a geissele MK4
Saved 4ish ounces switching from a specwar 556 to a Gemtech trek
Next up is the barrel. "Get both" is not an option

As per Geissele's website, the 9.5" MK4 weighs 11.2oz w/barrel nut. The MI G3 9.25" M-Lok rail weighs 7.2oz w/barrel nut.  That's a quarter pound right there.

Maybe switch to a lightened gas block or a Ti gas block.  That should be good for another ounce or two I guesstimate.

Other than changing out the stock, grip(s) and maybe the upper to a "slickside", the only options I see after that are going with Ti takedown pins, castle nut, etc.

eta- created post before the edit

I say new barrel or cut and thread.

Thanks for the reply. Gas block will be a govnah, gas to the face sucks!

Even better: If you're going to dedicate that Trek to this one gun, get a Baby Govnah. Way lighter, way smaller, no moving parts.

As far as the best way to save weight on that barrel, I'm not sure which would be lighter. But I bet it's very close either way; choose which length you would rather have.

So everyone dotes on the 11.5" for dwell time. Is that still a concern?
ETA: recommend me a gas port size. My issue is is shoot Tula all the way up to 75g TAP which is why I wanted a govnah

I've yet to have a malfunction with my 10.5" using USGI magazines. For me, it's just personal preference with the suppressor to have it as close in as possible to reduce the necessary leverage.

I should've taken pictures, but just a couple weeks ago I *finally* had a failure. After a couple thousand rounds suppressed without cleaning (just blasting some RemOil through the ejection port as needed), the BCG finally had so much stuff built up in it that the firing pin was stuck inside the firing pin channel, the cam pin wasn't rotating, and I had to pull the charging handle twice to overcome the friction from the baked on carbon.

After double-charging, it fired fine. I decided to go ahead and clean it for convenience, and that's when I discovered the firing pin virtually welded in place. That actually scared me because it could cause a slamfire. So when it comes to unreliability of a 10.5"...don't worry. They've worked the bugs out.

On the plus side, WOW my rifle is smooth now. You should really clean these things sometimes.

For the gas port size, I did 0.049", and I shoot 100% XM193 and reloads that mimic XM193 and it cycled fine with an H2 weight buffer. I swapped to a carbine weight buffer just to save overall weight and reciprocating mass since the rifle was no longer horribly overgassed. So a 0.042" would have probably been fine with XM193, but this is my home defense gun so I erred on the side of caution. Since you're not using Tula for home defense, I would say just go with 0.042" or 0.049" unless Amphibian says otherwise.

.049" and a carbine buffer?
Currently using an H2 and that could help me on weight too

Yep, carbine buffer. Between that, the Baby Govnah, and cutting/reprofiling the barrel, you could probably shave almost half a pound.

I'm kinda leaning towards cutting the barrel. Not sure how a 9.5" rail would look with the 11.5" barrel