Ar wont pick up next round

[Marty McFly]

Update, didn't have much time because I was concentrating on getting a prs gun dialed, but.... the new bolt is now cycling, but catching short on the last shot. When the magazine is empty the bcg is catching on the carrier instead the bolt face. I'll go back switch buffer springs.

Did you check the gas system?

 

[pastera]

Disassemble the BCG, clean, deburr heavily lube and reassemble.

Pull the gas block and check for blockage/burrs

Reassemble everything and run the BCG very wet until broken in.

Also lube the buffer and spring - doesn't need a lot because if you run the BCG wet it will transfer some lube.

Swapping a new, stiff BCG into gun that's well broken in can mask some excess stiffness.
If flicking your wrist quickly with a closed BCG doesn't extend it, then it likely is too dry, not broken in or dirty.

 

[akdov823]

Did you check the gas system?

The gas block isn't loose or showing any signs of gas being released around it, the tube is tight and has a good overlap mark on the key way, and the key on the bcg is staked and straight

 

[akdov823]

Going to figure this out tonight, and that's it!

 

[Uzi2]

Going to figure this out tonight, and that's it!

First thing I'd get rid of is that AR cut bolt carrier and put in a standard M16 cut carrier. It will have a little more weight/inertia.

Of all the ARs I have, only one ever had an AR cut carrier and that was replaced the moment I opened the rifle the first time. It sits in a tube as a last resort spare.

 

[Gasgunner]

I’m siding with the short stroking opinion. Either the BCG is just light enough to not travel fully rearward, or it’s catching on something, slowing it down.

 

[SgtHal75]

I’ve had this problem before with steel case and a high end bcg. Used a beat up milspec bcg and it ran fine.

 

[50wt]

I have a 14.5 midlength barrel with an m16 cut bcg and it cycles reloads that are 2450fps reloads.

 

[chris_1001]

Going to figure this out tonight, and that's it!

Gonna need a bigger hammer…

 

[mcshooter]

Did you feed it brisket and beer?
Otherwise it will not cooperate.



But for real sounds like the buffer is short stroking.


Commercial buffer and tube on a milspec lower?