I've got a 270 WSM and the inside diameter at the end of the brake is about 0.415 in. A 300 RUM and the inside diameter at the end of the brake is about 0.335-0.340in. A 338 WM and the inside diameter at the end of the brake is about 0.375 in. How and/or why does the brake on the 270 WSM have a larger diameter? Could a break off a 300 RUM be used on a 270 WSM? At first is would seem that a 30 cal brake would be way over bore fore a 270 cal, but it would actually be a step down in this case? I am asking because I am attempting to build another 270 WSM and I have a barrel and now an extra 300 RUM brake.

Thanks,

JBS