Home Forums Hunting & Shooting Ask The Gunwriters 300 H&H from 375 H&H

I am having a Rem Model 700 300 H&H barrel delivered to replace the barrel on a Model 700 in 7mm Mag. Finding 300 H&H brass is a little difficult but I have several hundred once fired cases in 375 H&H. Since both rounds are based on the same case I am considering necking down some 375 H&H brass to 300 H&H brass. I plan on doing it in 3 stages: Full length size and deprime the 375 cases. Run the cases through a 300 H&H die without the decapping pin and then running the cases through a 300 H&H die with the decapping pin in place. Then check neck thickness and length and trim accordingly and fire form the cases.

In my mind this should work. What are Y'All's thoughts? Doable with normal dies? Or should I have RCBS make me a sizing die from 375-300? Not sure that would be needed. I am curious if anyone has done this and if they ran into any issues.

What I've done:

Anneal
FL size in 300 H&H die
Square neck
Chamfer

No issues

I would think annealing would be a good idea too.

When i neck down, i typically neck turn first . I made a lot of stuff from Fed gold medal match 308 once fired. I had to neck turn on several rifles as the necks were too thick.