OK, we've had some good discussions about esoteric casting topics, so here's another...
How is it that a Gas Check really works?
I've heard -
1. That it scrapes the lead away that is laid down in the barrel by the front portion of the bullet's passing. (A second similar argument is that it scrapes away lead left in the bore from previous shots...)
2. That it prevents the super-hot sand-blasting effect of the powder gasses from melting the lead base of the bullet, which in turn leaves lead in the bore...
And, while this isn't a theory - I've also heard that it is permissable to use lead bullets with gas checks in firearms that otherwise aren't supposed to see bare lead, such as the M-1 Carbine or Old-Model Ruger 44 Carbine. Any input on that?
(And, if you do, and say that it does allow this, please explain why/how?)