u/Detailed_Firearms

Work in progress, obviously.

I'm setting up a new Aero M5 .308. Using Aero factory upper like this: https://ar15discounts.com/products/aero-precision-m5-complete-upper-20-308-ss-rifle-barrel-atlas-r-one-15-m-lok-hg-anodized-black/

Using an Aero M5 lower with Aero M5 lower kit. .308 buffer, tried AR15 spring and an AR-10 +15% spring, I think it is a Griffin.

With the AR15 spring, fire first shot, bolt would grab the next round about 3/4" up from the rim and the cartridge jams at an angle.

I should have read that as undergassed, but didn't and went the other extreme with buffer spring and tried the +15% spring. Fire first shot and cartridge does not eject on its own and is hella tight. I can extract it with the charging handle, but barely. Don't have to mortar it, but close.

So I pulled the handguard and the gas system off the barrel. Gas tube and block are clear and free-flowing. Barrel shows a little gas escape at the port, but not much. Gas port on the barrel pins out at .084". That's way too small, isn't it?