Hey all.    Not too long ago I installed a 4 pos. collapsable stock on my bushy.  Since then I've been experiencing frequent FTFeeds.  Im using the same upper, the same mags, and the same ammo as before.   Never had any functionality problems until I installed the 4pos.

My best theory on the subject is the new buffer/spring is allowing the bolt to retract far enough to extract and eject, but not enough to strip a new round off the mag.  (manually charging the rifle loads a round just fine).  thats just my thought, and Im hardly an expert on the subject.


So hopefully the experts might have some suggestions/thoughts/ideas for me?

Carbine buffer (read not the long A-1 or 2 type)?

Buffer spring 10.5" free lenght, and 11.75" free lenght of the A-1 or 2 style, and the end of spring coils free of burs that could be scrapping down the tube/buffer and slowing down the actual cycle of the action?

Buffer bumper roll pin flush with the sides of the buffer, and not hanging out and catching on the inside of the buffer spring?

manufacture unknown. was a funshow pickup.  No markings of any kind anywhere on it.

The factory original spring is 12.75 inches and the original buffer is 6 inches long.

The new spring is  11.25 " and the new buffer is 3.25" long.

Spring looks good. no damage or burrs that I can feel.  Roll pin on the buffer is flush.

Had that occur with a low end tube. There were burrs and bits of aluminum remaining in the bottom from the machining process that bouced up and got between the the carrier and tube wall.  This slowed the carrier group enough to cause it to fail to lock just enough sometimes that it was visible but enough ...Try flushing it with brake cleaner to kock out the loose stuff.  The right size brake hone (after removing tube from receiver) can be used to polish the interior of the tube.  Had no more problems.  Learned my lesson bying cheaper parts when trying to build the kid's gun on a budget!  But it has worked fine since.