450Bushmaster.net

I had a chance to shoot my 284 brass. Using LG and Rem 9 1/2 primers I got:

36.9 gr LG averaged 2163. SD was acceptable so I did not record that.
37.4 gr LG averaged 2190. SD was acceptable so I did not record that.

On brass shrinkage:

I started at 1.70. I had new brass and once fired brass cut/trim into 450 BM. I got the once fired brass as such, but I am sure it was fired more than just once.

The once fired brass did not shrink at all.

The new brass shrank ~ 0.003 when fired at 2163 fps.
The new brass shrank ~ 0.005 when fired at 2190 fps.

Accuracy was good for me. I will shoot a deer or zombie any day with this. I shot 35 rounds total and I did have a couple of the new brass rounds fail to fully chamber after a fired round, but they chambered fine after that. They did have a slight bulge to one side, so it was probably a canted bullet seating issue. Fun project and I learned alot.

paulmark3010 wrote:I got the RCBS cutter sized for a Forster pilot today. The Forster reamer works great on my RCBS trimmer. My 284 brass is 1.70 long. I will be using Rem 9 1/2 primers. How much do I need to reduce my load compared to the small primers? I will be starting with 250 FTX and LG. In my 16" I was getting about 2150 fps with 250 FTX and 37.9 gr of LG using WSR primers. Any help would be appreciated. I also have some 240 XTP mags, 200 FTX and 225 FTX. Thanks!

After your tip, I ordered one also, along with a Forster reamer for another project (.429) and they arrived yesterday. Great solution to the different stud size issue and a pretty nice cutter head to boot.

Thanks for running that to ground Paul.

Hoot