The quick solution is to polish the adpadter slots and raisl so the bolt moves more cleanly on them, and install a reduced tension hammer spring so the bolt can cycle a touch easy as well.  Also to point out, first few hundred rounds down the pipe, use CCI min mags since they have a touch more ass to cycle the adapter correctly until it mates in.

Next, would help to know which mags you are using, but on these, give them a quick clean, and if you are using a mag block, make sure that the bolt is set correctly, and if they are the mags that fit a standard mag well without an adapter block, make sure that the mag catch threaded section is flush with the face of the release button so the mags are correctly retained i the mag well.


Also, take a photo of the chamber adapter piece pulled form the unit,  since I need to see up the feed ramp to the chamber to make sure that there is not sharp chamber entry edges that may be causing the Jam.   And for the love of god, do not take anything to the inside of chamber to enlarge its entry diameter thinking that this will allow the rifle to feed better.  It may help the rifle feed better, but the over size chamber entry is just going to cause all kinds of short stroking issues with the increased blow by at fire forming, blow back cycling.  At most, you only want to radius the entry lip edge to the chamber if round to be sharp and snagging the brass instead.  Up the feed ramp, if it rough as hell, it can be polished, but do not change the angle of attack to the chamber, or touch any part inside the chamber.

Feed ramp does not look too bad, and the chamber will polish out through live fire and bit of cleaning with a brass brush. Again, do not enlarge the chamber with anything other the normal cleaning, since it will cause blow by problems at ignition and lead to short stroking issues.


Now need a photo of the bolt face, and just want to check the bottom edge of the bolt face where the rim of the round has to climb up it as it being release from the mag lips and angles up the bolt face as the round is being feed into the chamber.


Also, need to see the claw of the extractor, since as the round is being angled up the bolt face, need to make sure that the claw of the extractor is not cutting into the side of the rim and slowing down the load as well.

And again, might need to go to a lighter tension hammer spring until this unit mates in so its full cycling (why you want to break the unit in with mini mag ammo since it has a tad more power than standard ammo to make sure that the unit it full stroking all the way back).

Can't tell if that is lead, or just the face of the bolt not milled correctly, but straight down from the ejector the rail, the side of the bolt face on that side should be rounded like the other side so the rim of the round can sit flush.

So on that note, remove the bolt from the rail, clean the bolt, and if needed, might have to clean up the right hand side of the recesses if not milled correctly.


As for the round staying in the chamber on a manual extract, it's due to the round not seating fully flush in the  bolt recess so the extractor claw can slip onto the rim (again, could be what every the hell is the build up on the face of the bolt recess just below the extractor on the rail).

Three areas I see as a problem child.



First is the extractor, being that as the rim is loading past it for the claw to lock on to the rim, the  case rim needs to be able to push it outwards, and the outer taper from face should be a lot smoother.  I can't tell if the extract tip is broken off, or just a bad edge milling and the tip of the claw bent outwards instead.  Either wall, the extractor should be replaced, and before you install it, make sure that the outer round is smooth so the rim can glide down that edge and push the extractor out to allow the round to lock in place in the bolt recess channel.  


Next is the recesses channel at the FP channel, and it looks like when the FP channel was drilled, it distorted the recess of the bolt so it no longer matches what would be the roundness of the an ammo rim.  Myself, I would lathe the bolt up, and make a light pass on the recess walls to clean up the FP channel bur to remove it/make the face recess channel round again.


On the bottom of the bolt face recess (bottom numb), Although the very bottom of the edge is bevel'd, I would still use a stone and radius the sharp edge from bevel to bolt recess face surface that still exists.  As stated, as the round is being pushed out of the mag, it that edge that the rim has to glide against for the rim to be able to slip up the recess channel and into place (with the extractor slipping over the rim as well.

Short of that, and the other few areas that I have already pointed out to polish, the only other thing that comes to mind would be reduced tension hammer spring if you are using ammo less than mini mag ammo strength, which will insure that the ammo will full cycle the bolt each and every time.

Could be build up at the last of the chamber cut, but with the 22lr insert type kits, it so easy to just clean the chamber insert out side of the rifle, he would have had to really let cleaning go to allow it to build up to the point (way to easy to just clean the chamber insert out of the barrel with a good Lead cleaner and Brass brush to get the chamber section clean and gleaming).