I'm building a 375 Whelen AI. I've got dies and brass. I've shot it a couple of times after chambering to ensure that my fired cases, dies etc were compatible. Good news is the 35 Whelen cases necked up to 416 and then down thru the CH4D dies and the fired cases seem to have worked out fine. I've sent the chambering reamer back. (chambering by hand is a longer process than I remembered) Reamer was rented from 4D reamer rental, A case full of IMR4064 and 270 gr RN blems from Midway seems to be a mild load with rounded primers.
The action is a Mouser - 98 from Checksolvokia (sp?) made between the wars. The barrel is a 2 1/2 contour 22" from ER Shaw. The stock I bought here on 24. I'll put a 1/2" decelerator pad on it. And will hire someone with the proper jigs to attach the Lyman steel aperture site and the front post sight.
I bought "a bunch" of these 270 gr RN bullets a while back when Midway was dumping them.
I've freefloated the barrel and am about to glass bed the action. Still need to put a finish on the barrel led action and the stock.
I've searched the internet and bought a book - "Big bore rifles and cartridges" but am still looking for loads. I have molds and gas checks, Linotype and wheel weights.
If anyone has experience with this cartridge I would appreciate hearing about your experience.
It seems that most shooters use IMR 4064 in this cartridge. I'm thinking maybe TAC, IMR4166 or one of the 4895's might work well.
What would curl my toes would be shooting 235 - 270 grain cast bullets at ~ 2,300 fps. Finally I have a pre-64 375 H&H AI so I don't need > 65,000 psi loads.
Last edited by Bugger; 05/18/17.
