View Full Version : Drilled barrel pin, new problem.
12-15-2006, 08:49 AM
Well I drilled the barrel pin with a 6.7mm .2638 carbide drill bit smaller than recommended, next time I will use a 5mm and then press out the shell. The drilling was very easy to do, I stopped a lot and cleaned the chips and inspected as I went.
I did a fairly nice job I thought, pressed out the remaining piece of pin.
My problem, I can slide the 7mm rod through the hole and it's lose, I don't want to drill an even bigger hole. I haven't pressed out the barrel yet.
Can I use something like JB weld along side the new pin when I reinstall or should I look for a grade 8 bolt and make a larger pin to fit this hole? Do I even need a grade 8 would a grade 5 be hard enough? The grade 8 cost pennies so it's not a cost issue, I was thinking maybe a grade 5 pressed in might hold tighter than the hardened grade 8.
12-15-2006, 11:19 AM
If there was a piece of the pin left after you drilled it out and that you had to press out, I would try and see if another barrel pin will just slide thru. The barrel pin is an interference fit and would be bigger than the hole. Chances are your fine and a new barrel pin will press in ok.
12-15-2006, 12:30 PM
Center punch the pin in a couple of locations, that should provide enough for an interference fit.
Kinda like Knurling a piston or valve guide like we used to do in the old days
12-15-2006, 12:49 PM
sometimes you can do a shade tree knurl job with the jaws of a vise.
12-15-2006, 01:19 PM
I'm not sure what the knurl job is, I'm guessing expanding the pin by compressing it some?
I only got one side of the old pin out, I think I made the hole slightly bigger and maybe not completely round anymore. It looks fine and I did go slow and stop many times I thought I was dead center but there was only pin left on one side of the hole.
That's why if I have to drill out another one I will use a 5mm bit to be sure I have old pin left and don't enlarge the hole any.
I will check another barrel pin to see if it also slides right in by hand, if so I guess it's make one out of a bolt.
PS As a side note what happened to our post count and trader rating they dropped big time?
12-15-2006, 06:02 PM
If you egg shaped the hole during the drilling process and a standard bbl pin easily pushes through, I would drill it out slightly oversize to get the hole perfectly round again. Since you would be making a custom pin the size would not be an issue, but the pin or bbl possibly shifting due to an oblong hole might be.
12-16-2006, 08:36 PM
If you can get the barrel pin hole round with a .280 reamer, i have extra oversize pins, .281. Just tell me how long you want the pin. The ones i have are 6 in. long. PM if i can help. Paul
12-19-2006, 01:49 AM
no JB weld! if the stuff breaks up and the barrel moves forward causing a head space issue you can blow your dam head off! drill it out to a larger size aprox .002 smaller than the new pin. dont use some soft hunk of unknown bolt get a proper pin. I recomend you check head space when yoyu get this thing straightend out.
12-26-2006, 12:53 AM
If you ever have to drill out anouther one, use a softer bit, that way if you hit the trunion, the bit will follow it instead of cutting into it.
12-31-2006, 05:29 PM
get some drill rod in a size a couple thou. bigger than your hole. Harden a peice of it and replace. Victor machine has metric and numbered sizes of drill rod.