Ar wont lock open on last shot.

[djkivley]

I recently purchased a dpms oracle( so please forgive me if i dont use the correct terms) and im having trouble getting the bolt to stay locked back. The first time i took it the range it fired off 150 trouble free rounds and the bolt locked back after the last round of a magazine was fired( i used federal .223 rem 55 gr. fmj) i took it out yesterday and put 300 rounds through the rifle and after the third magazine the bolt would no longer stay back after the magazine was empty( used federal 5.56 bulk ammo) any help with this problem would be great.

 

[JCR]

Do you have another mag? Have you tried another mag? If you don't have another mag, I'd get one and see if the bolt will lock with the new mag.

 

[live4the1]

I would suspect the mag. Does it only happen with one mag? Check to make sure that your bolt catch is functioning correctly.

 

[djkivley]

Ive used two different mags( stock mag and bushmaster mag) and the bolt catch i believe is working because i can lock the bolt back manually.

 

[Warbirds]

With an empty mag in the gun pull the charging handle all the way to the rear and release. Does it lock back? Please clarify what you are doing to lock it manually.

Sent from my SPH-L720 using Tapatalk

 

[djkivley]

Yes it locks back when i pull the charging handle with an empty magazine in. It locked back with both the dpms and bushmaster magazines. I was able to fire another magazine from the rifle and it still didnt lock back after the last round was fired but it locked back immediatly afterwards when i pulled the charging handle.

 

[Mobuck]

Could be the bolt catch plunger is still a little sticky making it function too slow to catch the bolt when in normal cycling. Put a couple drops of CLP behind the bolt catch (plunger/spring recess) and move the catch manually several times while watching it for proper function. Another drop or two on the pivot point might help. Next possibility is the bolt is not fully cycling even though it ejects and picks up another round. A very slight short stroking can cause the bolt to not retract quite enough for the bolt catch to rise and stop forward movement.