New build won't cycle......help

[tmsand338]

I just finished my first complete build, all the function tests checked out and I am able to cycle rounds in and out of the chamber by hand. However, when I fire the rifle it ejects the spent case but does not feed a new round in or cock the hammer. I guess it's obvious that the bolt carrier isn't going back far enough.

This project has a rifle-length gas system and a colapsable stock with a David Tubbs buffer spring.

Can someone suggest possible causes for this problem and how I might check for said causes?

Thanks!

[ChunkyMonkey]

Try carbine length spring instead of all in one spring like David Tubbs.

[kwando]

Might have to enlarge (haha) the gas ports.

[mutt]

Try a standard carbine spring and carbine buffer. Is the gas block a pinned on FSB or a set-screw lowpro? If It's a set-screw type I'd check to make sure you don't have a gas leak.

[colorider]

Are you using Tula or wolf ammo ?

[MarkCO]

Could be weak ammo against an XP buffer spring...

Could be not enough gas due to a misaligned gas block, leaking gas from gas tube and or gas block interfaces...

Are you using a Geiselle trigger by chance?

[C Ward]

If the buffer or spring were bottoming out the recoil impulse would feel funny and the issues would show on a function check without firing .

I run the Tubb flat wire springs in all my guns with no issue's . My money is on a gas leak some where .

[BPTactical]

Come see me.

[Delfuego]

Come see me.

+1

[ray1970]

Barrel length? Ammo used?