Problem with gas...

[meatsauce]

Ok, I decided to build an AR. First trip out was yesterday morning to dial in scope and adjust gas block. Once I found the sweet spot with the gas block it would run through a magazine with no issues. Then I took a break, 4-5 minutes, when I go to shoot again there's not enough gas (ejecting but not stripping off the next round). Off with the handguard and go through the process again - shoots great until I set it down for a few minutes. When I go back to it - the same damn thing, not enough gas. I turned the gas up, down, every which way and it always did the same thing. What am I doing wrong?

[BitchinCamaro]

Try to recreate the same scenario, but this time when your bolt won't strip a round, shoot 5-10 after you cycle the bolt manually. See if heating up the chamber is enough to get it running again.

If it is, turn up your gas a click or 4.

You're probably not going to notice the difference in impulse, and even if you did at least your gun would still run when cold.

Do you reload? What powder are you using?

[CJW]

Beano.

(Don't know if that answers your question; I just read the subject line...)

Edited August 11, 2015 by CJW

[Brian04rs]

Got a good chuckle out of that??

[meatsauce]

Try to recreate the same scenario, but this time when your bolt won't strip a round, shoot 5-10 after you cycle the bolt manually. See if heating up the chamber is enough to get it running again.

If it is, turn up your gas a click or 4.

You're probably not going to notice the difference in impulse, and even if you did at least your gun would still run when cold.

Do you reload? What powder are you using?

I tried this but it would not run again until I fiddled with the gas adjustment. Then it would run as long as I wanted. As soon as it cooled down....nada. I did try turning the gas up quite a bit with the same results. No reloads, was shooting 55gr. Geco target ammo.

[BitchinCamaro]

If you're trying to avoid clicking up your gas, then try switching ammo.

I've not tried Geco rifle ammo, but my experience with their pistol loads is piss-poor; from the same box there were rounds that were super soft shooting and some rounds felt like they were going to send my slide back into my skull. Squib or Kaboom? No fun.

I would (and do) click up the gas a bit above the minimum.

What gas block are you using?

[BitchinCamaro]

[OPENB]

I would guess when your gun is warm, you're getting a good gas seal at the block or key from expanding metal. When it cools, just enough tolerance loss to lose the seal. How tight is your gas block to barrel fit? Same with carrier key to gas tube fit.

[ccoker]

I would try some different ammo too

[wgj3]

Maybe also clean chamber and lube BCG liberally...?

[meatsauce]

If you're trying to avoid clicking up your gas, then try switching ammo.

I've not tried Geco rifle ammo, but my experience with their pistol loads is piss-poor; from the same box there were rounds that were super soft shooting and some rounds felt like they were going to send my slide back into my skull. Squib or Kaboom? No fun.

I would (and do) click up the gas a bit above the minimum.

What gas block are you using?

Sorry guys, was out of town for a few days. I'm using a Seekins gas block

[meatsauce]

I would guess when your gun is warm, you're getting a good gas seal at the block or key from expanding metal. When it cools, just enough tolerance loss to lose the seal. How tight is your gas block to barrel fit? Same with carrier key to gas tube fit.

This is exactly what it's like. It's not the tightest fitting block. I'll shoot it one evening this week and pull the gas block to see if it looks like it's leaking.