FrankenGun Problem

Barrel : Bushmaster 14.5 + Y- Comp MB
Upper  : Unknown Manufactuer A2
Lower  : Olympic Arms....out of spec(tight magwell)
Lower P: DMPS
Bolt   : DPMS
Stock  : Unknown manufactuer 4 position stock


The Problem:

On random occasions, when the charging handle is pulled back, the bolt will only go back 1\4 of an inch and ride firmly on the bolt catch.

I then have to push the forward assist and re-cycle the bolt and then 90% of the time it works as designed.

I have tested 5 mags.

3 USGI all new

2 Brit steel all new.

The gun is not picky as to any mag. as it is completely random. However the lower is a tight fit with a majority of the mags.

Is it possible that i used the wrong spring for the bolt catch? Or just a shitty lower?


any info would be great.

Is the bolt catch/release "sticky" when just depressing it with no mag?  In other words, I am thinking that maybe the bolt catch is sticking in the "Hold open" position, causing it to ride.  

I hope that the above statement makes sense....it is 1 am afterall.

Sometimes the receiver end plate of a telestock located at the back of the lower can stick up to high and stop the charging handle from going backwards unless you are pulling up on the handle so it go go over the high part of the plate. Also once i saw a sp1 style carrier that the milled ramp portion on the bottom of the carrier was so wide when an empty mag rasied the bolt catch and the carrier was pulled back the bolt catch would wedge in the milled portion of the carrier.

Quoted: Sometimes the receiver end plate of a telestock located at the back of the lower can stick up to high and stop the charging handle from going backwards unless you are pulling up on the handle so it go go over the high part of the plate. Also once i saw a sp1 style carrier that the milled ramp portion on the bottom of the carrier was so wide when an empty mag rasied the bolt catch and the carrier was pulled back the bolt catch would wedge in the milled portion of the carrier.

+1...That one had me scratching my head for a while once...LL

Quoted: Sometimes the receiver end plate of a telestock located at the back of the lower can stick up to high and stop the charging handle from going backwards unless you are pulling up on the handle so it go go over the high part of the plate. Also once i saw a sp1 style carrier that the milled ramp portion on the bottom of the carrier was so wide when an empty mag rasied the bolt catch and the carrier was pulled back the bolt catch would wedge in the milled portion of the carrier.

This was the problem.

Thanks