http://filebox.vt.edu/users/vitran/lower%20half.jpgI've had my Bushmaster lower, Bushmaster lower parts kit, and LMT SOPMOD kit for some time now. I ordered a punch set from Bushmaster, and it was taking a while to come in. So, I went to Home Depot and picked up a Stanley nail set with three punches covering the range from 1/32" to 3/32". The sizes didn't match up with those specified in the lower assembly guide, but I decided I'd give it a try anyways.
Everything was easy except for the trigger guard roll pin and bolt catch roll pin. The trigger guard pin required a surprising amount of force. I protected the pin with a few cleaning patches and started it with a hammer. About midway through, I noticed that the hammer was beginning to deform the pin, so I used a punch the rest of the way. Since the punch wasn't really big enough, the deformation continued, but I was able to "tuck" it in.
Trigger guard roll pin (55KB)As for the bolt catch pin, I protected the receiver with a cleaning patch and got to work. I started the pin with a hammer, then used a punch the rest of the way. I was nearly done and feeling pretty good, but then I lost my concentration for just a second.
Bolt catch (56KB)Overall, the build was easy, just like everyone said it would be. I think next time, when I have the correct punches, I'll be able to minimize damage. The exposed, dinged metal sure screams amateur!
have1) The safety action is very gritty. Quick transition is hindered. Is this normal or should I just lube it up really good?
2) The trigger does not always reset by itself. The disconnector kind of binds to the hammer I guess. Will lubricant fix this? The parts aren't totally dry, I just wiped off the excess oil it came with.
3) The back of the Tango Down Battle Grip is not flush with the receiver. Is this normal? I know Tango Down parts have the reputation of requiring exacting tolerances. Which part is the wrong size here, the lower or the grip?
Receiver/grip transition (55KB)