Mag brass

[Visionz45]

Ive been using 7mm rem mag brass to mess around with my friends 264 while I wait on mine. I was lucky enough to grab a bag of 264 proper brass of gunbroker(new). Both bags are winchester. Should I re-work up my loads using the new brass or am I fine? Secondly, with the 7mm brass I read that alot of folks turn the neck b/c re-sizing makes it to thick. I this necessary as well?

 

[rcmodel]

The only way to even guess would be to weigh fired, sized, and trimmed cases from both the re-formed 7mm Mag and the new 264 Win cases.
If they are fire formed, sized, trimmed, and identical length, and both weigh the same, for all practical purposes, they are the same.

If there is a noticable differance in weight, that can only come from thicker brass and less internal case capacity.



Neck reaming or turning is only necessary if the re-formed case necks are too thick to release the bullets in your chamber.
The way to check is try to fit a bullet in a fired case.
If it is a loose slip fit, no reduction in case neck thickness is needed.
If they won't slip fit in a fired case without effort, the necks will need thinning by one or the other method.

rc