Large chambers

[Mr.doug]

Update: ok did a real good chamber cast today, chamber length 2.105, not bad, than an approximately a 30 degree lead that is .075 long to riffling. Here’s the kicker riffling is lands .4495 and grooves .4555. Case mouth is .483 in dia. Minus
Case wall thickness leaves a .461 dia. Bullet, so when bullet obstrates to chamber it has to size down to grooves
The math tells me .0055 that bullet is sizing down. That sounds like way to much. Correct me if I’m wrong , but I think no matter what bullet I use it’s going to lead the boar. What do you all think.
Thanks

Doug

[Don McDowell]

Most of the excess lead shaving down to the barrel measurements should be absorbed by the lube grooves.wide lube grooves will help keep lube pumping on the barrel.
It might well be worth getting ahold of some 461 bullets to try, as with smaller bullets are still liable to give gas cutting blowby