Making 404Jeffery Brass

Capt_Oscar

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In these trying times where brass has become scarce. I want to keep my 404Jeffery headstamped brass for Africa. So I wanted to make my own. While there is a thread on these forums about forming 404J from 375H&H; the smarter choice is forming from cases that use 404J as the parent case. I'm referring to Remington's Ultra Mag lineup. The differences in case dimensions is completely negligible to the point your can simply run 375 RUM through your 404J full length sizing die (assuming you have a tapered expander button). Load and shoot. You'll see in my loaded cases where the neck/shoulder joint was on the 375RUM, in the pics showing the loaded rounds.
The only, very minor issue, is the formed case comes in at 2.840" which won't allow for crimping the bullet. However, the neck on the 404 is so long it really doesn't need a crimp (in my opinion). If you still wanted it crimped, send 3 fired cases to Hornady explaining you want a custom factory crimp die - not the standard 404J die and they can make it for you (at a nominal cost).
Next question: how is performance compared to actual 404J brass. Well, keeping the same overall load length I experienced no velocity difference and accuracy was quite good.
Isn't 375RUM just as hard to find as 404J brass?? No, actually ADG makes 375RUM brass at a really decent price. Significantly cheaper then 404J brass.
 
Loaded rounds
 

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Had some virgin RP brass to experiment with. I did lose 3 cases out of 26 due to miscalculations on my part.
 

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Rattler1 wrote on trperk1's profile.
trperk1, I bought the Kimber Caprivi 375 back in an earlier post. You attached a target with an impressive three rounds touching 100 yards. I took the 2x10 VX5 off and put a VX6 HD Gen 2 1x6x24 Duplex Firedot on the rifle. It's definitely a shooter curious what loads you used for the group. Loving this rifle so fun to shoot. Africa 2026 Mozambique. Buff and PG. Any info appreciated.
Ready for the hunt with HTK Safaris
Treemantwo wrote on Jager Waffen74's profile.
Hello:
I’ll take the .375 Whitworth for $1,150 if the deal falls through.
Thanks .
Derek
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