.350 RM Case Forming

[hpluseleven]

I have a Remington 673 Guide Gun in .350 Remington Mag that I really like and I'd really like to shoot more. But I need brass to load! I have looked at: Midway, Natchez, Graf's, Cabelas, Basspro, Cheaperthandirt, Midsouth, Academy, Gander Mountain and several local gunshops and I can't find .350 RM ammo or brass anywhere.

I've read that I can make .350 RM brass from 7mm RM (which I also shoot, but I have more brass than I need) or .300 Win Mag/.300 RUM/several other belted mag cartridges which I don't shoot yet have picked up range brass for.

I have .350 RM dies. Can anyone talk me through this process? Based on what I've read, I think all I have to do is run my 7mm brass into the .350 die and then trim to correct length. But we're talking a LOT of trimming - will the 7mm brass fit all the way into the .350 die? Or will there have to be intermediate steps of resizing/trimming/resizing/trimming/etc?

I don't mind the time/labor involved in the process (as I understand it) but I could use some more help figuring out exactly what I need to do.

Anyone else shoot .350 Remington Mag?

Thanks for your help.

 

[Curator]

Remove the de-capping pin from your .350RM full length sizing die. Stand the 7mmRM cases in a pan with 1 inch of water and heat the shoulder area with a propane torch until you get a uniform discoloration (around 600 degrees) Annealing the shoulder area is necessary to be able to form your cases correctly. Use a good case lube but not too much or you will get dents in your new cases. Go slow, stopping a couple of times and turning the case being formed 90 to 180 degrees. Once your press ram touches the bottom of your sizing die your done with this step. Next trim to length and chamfer the case mouth inside and out. Some fired belted magnum cases have a bulge in front of the belt and may requre the use of a special die to remove this before they can be used. I belive Lee Precision sells such a die.