dawg180
Ar-15 Guru, Uzi Novice
I have a post sample Mini Uzi I built, used one of the new old stock bolts from McKay, and although it initially worked in testing, the bolt is now running away.
About half the vertical surface of the feet on the bolt have the angled cut on them, so what appears to be happening is in dry cycling the sear feet will catch *just barely* and lock it open properly, but in actual firing the vibration and cycling of the gun will overrun the sear pads as it is hitting the angled ramps on the front of the feet, not the flat surface.
There doesn't seem to be any slop/room with the top cover, although I could try tapping/bending it down a little bit to press the bolt down and make sure it isn't over-riding the sear pads.
I figure my options are:
1. weld up the front of the feet, recut the bottom chamfer angle closer to that on the BarrelXchange bolts (my concern here is heat treating them- I could hit it with a MAPP torch and then dip in water or oil to harden, but don't want the feet to crack/shatter and end up with a runaway gun)
or
2. Shave a bit off the front of the feet, maybe 1/16" which would still keep the bolt behind the magazine and cartridge and locked open, and move back the face of the foot so the start of the angle cut ends up being lower.
Any advice is appreciated!
Dawg180
About half the vertical surface of the feet on the bolt have the angled cut on them, so what appears to be happening is in dry cycling the sear feet will catch *just barely* and lock it open properly, but in actual firing the vibration and cycling of the gun will overrun the sear pads as it is hitting the angled ramps on the front of the feet, not the flat surface.
There doesn't seem to be any slop/room with the top cover, although I could try tapping/bending it down a little bit to press the bolt down and make sure it isn't over-riding the sear pads.
I figure my options are:
1. weld up the front of the feet, recut the bottom chamfer angle closer to that on the BarrelXchange bolts (my concern here is heat treating them- I could hit it with a MAPP torch and then dip in water or oil to harden, but don't want the feet to crack/shatter and end up with a runaway gun)
or
2. Shave a bit off the front of the feet, maybe 1/16" which would still keep the bolt behind the magazine and cartridge and locked open, and move back the face of the foot so the start of the angle cut ends up being lower.
Any advice is appreciated!
Dawg180