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Barrel trunnion

5K views 10 replies 9 participants last post by  OldSoldier 
#1 ·
New to the forum! Just figured I'd start off with some questions about a 1919 kit I picked up a couple of days ago. Namely, the barrel trunnion. The screw securing the barrel jacket in place was destroyed at some point, leaving the remains stuck in the trunnion. What type of screw is this, and what size is it? Furthermore, what (if anything) can be done for the threads in the surrounding area?

 
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#2 ·
BCLX1.1AB Which in English is flat head machine screw #10 (32NF thread) X1/4 inch long. It is Parkerized. You might be able to chase the threads with a #10-32 tap, if that doesn't work, drill and tap fro the next larger size and grind the diameter of the head down to the same size as the original.
 
#3 ·
And, if you can get that remnant carefully centerpunched and drilled out, that 10-32 tap should do fine. Also, since your trunnion/jacket threads are a little messed up there, a thread file might come in handy to clean that up. It's 22 threads per inch on that.
 
#5 ·
I have one with a similar problem. The hole was trashed so they put a new tapped hole on the other side and since the shroud they sent me was junk I got a new one from Jeff at iron creations with no screw hole. Getting the broken screw out if the the break is uneven can be done best on a mill with a small two flute end mill to flatten the surface. Then drill but saving it is going to be iffy.J.R.
 
#7 ·
McMaster Carr has them, but you have to buy a box of 100 and they are zinc plated. Easy sandblast and park. Biggest challenge I find is that the jacket hole/countersink is often larger than the heads of the available commercial screws. Anyone else here see a need for some large head screws that can be fitted well to jackets with oversize holes?
 
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