Want to mount a Lyman 48 on a US Krag, gunsmith says receiver is just too hard to drill. Now I have seen innumerable Krags with 48s on them so there must have been a solution to this problem, hopefully without putting a torch to the receiver and softening the whole thing. Vaguely recollect reading about putting a drop of solder on the spot you want to drill and leaving the tip of the iron in it for a while. Any suggestions would be helpful.