u/Far-Sorbet456

The BALR does fire fine, the three rounds I got through…. The bolt retainer is the week link - it broke on cycling out the third and in with the forth round, and the bolt carrier partially popped out the back. No big deal but I couldn’t fix at range. I saw someone else complaining about this part - it’s very small and fragile. I had dry cycled it and with snap caps a hundred times or more with no issues. I might be more aggressive with the bolt at the range I guess, but either way, it’s going to happen. Easy to reprint, but I’ll have to take off the optic and pic rail to reinstall, assuming when it got pulled out from the wrong side, that there was no damage to the upper receiver that will require a reprint. I going to try to make this part from a block of aluminum. It’s a tiny 3d part so can’t SCS it. Nothing to do with operation, but I regret doing the integral rear bipod. They are flimsy and don’t really lock in place well. If I had known, I would have just printed the medium sized hand guard. They look cool, but that’s about it. I’ll be shooting with the handguard on a pile of range bags

Finished up my UMP and operation is a bit on and off. Having a few problems - trigger isn’t resetting sometimes/ bolt doesn’t go fully into battery. Sometimes it works sometimes it doesn’t but I haven’t got through a whole mag without a few issues. I load it, slap the charging handle, and then click, nothing. So then I’ll drop the mag and just slightly pull back the charging handle and let go and it feels like it seated a little better - pull the trigger and I get a fire. Occasional failure to eject. Specs - PLA Pro/ Velocity barrel and trunnion. KAK bolt assembly. Just a mil spec trigger group. Using both the curved printed mag and metal Sten mags with the adapter. It’s the full sized model, not the mini. The final thing is I did put in the short stroke buffer from the start. I’m partially suspecting this might be the issue with the bolt going into battery and maybe the trigger reset issue. I couldn’t take apart at the range, but will remove the short stroke buffer and try again. I wasn’t really sure why I needed it, other than it was in the video and some folks said it would slow wear on mags and receiver. I’d rather reprint a few parts than deal with cycling bs. The extraction issue might be the extractor - I’ll remove and file a bit. Also I was wondering, with these AR/MAC11 combos, should I round over the hammer a little to improve cycling?