Originally Posted by rep1954
I'm going to be doing a pin and weld job on a 11 1/2" barrel and a 5 1/2" flash hider for the first time and need to know what diameter I should use for the pin and how deep must it enter the barrel? Is a high speed or cobalt pin okay for this or should I use something else? Should a crush ring be used?
I do pin and weld jobs almost every day.
I use 3/32" dowel pins in 3/16" and 1/4" long depending on the diameter of the muzzle device and the bore size.
I like to see 0.050" to 0.060" of the pin below the top of 28 pitch threads.
Depending on the muzzle brake diameter, sometimes I have to shorten a pin a little bit to get to this dimension without drilling so close to the bore.
Hi speed steel bits are fine unless you have a hardened muzzle device.
Then you might need carbide.
There are some really hard muzzle devices out there!