Thread: Jw15 modifications

So the plans with this have changed slightly, was in at Guncity the other day and they had a very beat up JW15 on the rack for $100 which was too much but picked it up on sale for $75 yesterday. Other than the buggered stock the firing pin didnt engage on the sear all the time and the base plate slid off the bottom of the 10rnd magazine, the barrel looks ok and has been cut down and threaded. So basically I took a gamble that looks like it should shoot ok and is cheaper than cutting down the one I had.

Anyway I pulled it apart and the sear has either been ground down or worn down from rubbing on the file like surface of the underside of the firing pin so it didnt have enough engagement. It was also quite rounded so it got attacked with a fine stone. This does change the angle and remove even more engagement, however the trigger blade I made can adjust the engagement so this isnt a problem anymore, alternatively you could file down the original trigger just in front of the 2nd stage screw to restore engagement.


The bolt got dismantled and deburred, especially the protrusion that picks up the round, all three sides of this were smoothed out with a diamond lap, the sharp edges were taken off the extractor pin grooves and the extractors were deburred and the edges broken (except the hooks). The firing pin was smoothed on the bottom surface that runs on the sear and the back end that is broached or shaped was cleaned up. The magazine guide/ejector was also cleaned up with a diamond lap and the burr in the action from the locking lugs was taken off.


It engages the sear 100% now and wont disengage with vigorous banging on the floor. Im not keen to chamber live rounds at home but surprisingly it will feed 10 fired shells perfectly so Im going to assume it will work.

What other bits are people cleaning up on these? NZrimfire seems to be pretty dead now days