Recoil Plate - How many screws are enough?

I\'m having a hard time getting the 2-56 holes in the box cam without breaking either a drill bit or a tap.  I have made two box cams (not cut yet) and one has 4 good holes and two partially threaded holes ( I broke out the inside slightly), the other one has a broken tap in one hole and two other that broke through. I was trying to transfer the holes from the recoil plate to the box cam. I guess I could try and relocate the bad holes to another location and re-drill them or weld some metal in the area of the break through. I guess the question is will 4 holes be enough?

manatee, are the good holes near the bottom area where the cocking rings are located? Those are the main screws that would absorb the recoil forces upon firing.
bruski

Yes the bad holes are on both sides of the slot. I just managed to correct two of them by drilling deeper so I now have one box cam with 5 good holes and 1 with 4 good and 2 partially threaded holes so am I ok with this? Is it worth trying to extract a broken tap from such tiny holes or just move over a bit and try again? Well tomorrow I\'m going to try and cut the slot in the box cams, I will use the best one.  I haven\'t been working on the gun the past 2 week as I got a new Tig welder and have been practicing.

Five good holes will work ok. If your tap broke while it was cutting the threads, it is probably tight. If it is above the surface any, you could try to work it out with some needle nose pliars that you can put a small piece of duct tape on each end to cushen the grip on the tap without breaking off pieces of it.
 I have removed many taps that were broke while tapping aluminum with nitric acid. The acid eats away at the steel tap without harming the aluminum any and the tap just falls out. This won\'t help you any in this case, but maybe in the future.
bruski

The tap broke off inside the hole so it would be almost impossible to remove it from such a small hole. The tap is HSS so even a carbide bit would probably break off. Thanks for your support! How is yours coming?
Bob

I test fired 10 rounds through it, they all fired but upon extraction 2 of the rounds extracted only half way out. I have some slight drill marks that didn\'t clean up on reaming so a little polishing on the carrier block is needed. I think that is what caught the rims while dragging them on the way out. I still have to finish the seat and handles on the carraige. I tried to cut the seat pieces from one piece of brass 6 inches long. The saw cuts made a gap plus cleaning up the saw cuts equaled a seat with large gaps. I need another piece of brass to do it over again. There must be over 500 dollars worth of brass in these guns.
bruski

Congratulations! At least yours fires. I have a ways to go yet. As soon as I finish the breech and box cam I will start on the bolts. Your right about the brass I know I have that much or more in mine. I\'m thinking of building the D&E tripod for mine since I have left over material from the carriage.
Bob