375 Rimless Nitro Express 2 1/4 Paper Patched

Attachment 291171

A while back I had a 375 Rimless Nitro Express (375 RNE) built. My rifle is built on a (BSA Monarch) Herter's U9. It has a 25" barrel. I make my cases from 30-06 brass.

I have been developing loads for primarily jacketed bullet. But my intent is to use cast boolits. I contacted Accurate Molds and we designed the 37-270M bullet. While I have had this molds for more than a year I finally got around to casting some boolits.

My goal was to work up a load using this bullet that would match factory ammo. Sometime I get lucky and on my first attempt I got pretty close.

While I was working up loads for jackets bullets I found that 42 grs of Rel 10X with a 270 gr FBSP clock-in at 2203 fps. So I used the same load with my paper patched boolit and it came in at 2229 fps. So far my group sizes are matching those for the jacketed loads I have used;1 to 1 1/2 Inch groups a 100 yards. I think it would produce smaller groups if I my scope had fine crosshairs instead of crosshair and a post.

Please remember this loads is safe in my rifle and it isn't published in any reloading manuals I could find. In fact, I could only find reloading data in The Cartridge of the World book. Nothing for cast boolits.

I have recently purchase a 375, 270 gr boolit mold from NOE but I have not used it yet.

A lot of people have provided me with data and I found some in a Mannlicher Schoenauer Collectors Association Newsletter.

I love Wildcat Cartridges and old oddballs like the 375 RNE. They are a lot of fun.

CA Dude

Nice.
You may find as I do and others that you will be getting less pressure with paper patched bullets.
I think it’s to do with the bearing length but mainly the paper and lead will compress down a lot easier than brass/copper full length gas checks.

That kind of accuracy to me is about what I have achieved as well. But not for large strings like other people but enough for practical hunting duties.

my rimmed .375 is a .375 JDJ, i get 2400 fps with a 220 gr bullet and 2100 fps with a 270 gr bullet.Attachment 291224

I have used 375 JDJ loading data for my 375 RNE with good results from jacketed bullets. The 220 grs have achieved 2496 fps and with the 270 grs, 2351 fps.

The neck of the JDJ is longer than the 375 RNE.

The case capacity for my cases is 67 grains of water filled to the mouth of the case.

I think I will firer up the lead pot tomorrow and cast some 270 grainers from my NOE mold.

CA Dude

I like it , I have a 375-06 that jes rebored , and they would seem to be very close cousins . Have not cast for it yet as I bought a large amount of jacketed that were on sale cheap as seconds .