DaveKing,

It would appear from your pix that you chamber is normal for the 38-55. There is little or no leade in these rifles so the OAL must be controlled. Any over lenght loads will not chamber. I have several rifles in both calibers and all are critical on loaded length.

Is it safe to shoot 375 Win. in a 38-55? Yes it is! But it will not be accurate so why do it? Doing so will offer no advantage or benefits.

Jim