375 Ackley Improved Loading Data

09 May 2002, 15:12

<mikeh416Rigby>

I've recently aquired a Winchester Model 70 in the 375 Ackley Improved, and I'm having a dreadful time locating reloading information for it. Can anyone help me out to get started?

09 May 2002, 15:29

<Don Martin29>

I have loaded 85 gr of imr 4350 with the 270 Hornady and 215's. This chamber is from Douglas.

I see loads in the Wolfe book "Wildcat Cartridges" and they look really hot so I am not posting them. The loads are "absolute maximum" in two test rifles and the suggestion is to drop them 10% for a start which would mean close to the load I used.

For the 300 gr bullet a suggested load interpolated from that book would be 82 gr of imr 4350.

Good luck.

I would get a program that at least uses the Powley formula for internal ballistics, a micrometer and a chorograph.

09 May 2002, 16:52

tsturm

quote:
Originally posted by mikeh375:
I've recently aquired a Winchester Model 70 in the 375 Ackley Improved, and I'm having a dreadful time locating reloading information for it. Can anyone help me out to get started?

Do a search in Big bores & reloading. I had asked this same question last Nov.
Good luck!! You will love your 375AI

09 May 2002, 17:39

<mikeh416Rigby>

Thanks for your quick responses. I found the postings you mentioned, and I've printed them out. I'm hoping to load it with the 250 grain Swift A-Frame for a plains game hunt that starts the 1st of June.

10 May 2002, 03:03

dan belisle

Hi mike. My 375 is the Weatherby version, so the freebore lets me load a little heavier, but the info about the Wildcat books is correct. The max load they use there is 90 gr of 4350, which is very, very hot. 2900 fps with 300 gr bullets puts you into 378 Wby territory, so the pressures must be extremely high. In my 375 Wby I find 85 gr of 4350 works the best (with 300 gr Noslers & Sierras). You should be able to use any 375 Wby data, just drop 5% and load up. Hope this helps. - Dan

10 May 2002, 16:49

<ol crip>

Mike, there are some loads in Ackley's Volume 1 page 487 for his .375 Magnum Improved (Ackley).

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KEEP YOUR POWDER DRY...OL CRIP
NUCLEAR GRADE UBC RETIRED

10 May 2002, 19:28

<.>

quote:
Originally posted by ol crip:
Mike, there are some loads in Ackley's Volume 1 page 487 for his .375 Magnum Improved (Ackley).

PO Ackley's data is from 1966. I'd be hesitant to load straight from that book. BUT, there's some significant discussion about loading generally in Ackley's books which is worth reading.

When you go to an "improved" caliber, you're pretty much on your own for working up a load. Be wary of ALL the pressure indicators.

Primers seem to indicate pressure before anything else -- usually as a cratering. But bolt lift, sticky extraction, extractor marks, shiny areas around the web . . .

You really need a chrono, a micrometer, and a good magnifying glass is nice to have too.

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.223 Ackley Improved Wildcat Forum:
http://www.hotboards.com/plus/plus.mirage?who=223ackleyimproved

10 May 2002, 19:48

<Sniper06>

All the info I have is from the 8th Edition of "Cartridges of the World":
200 SP IMR-4895 58.0 GR. 2450 FPS
235 SP IMR-4064 60.0 GR. 2475 FPS
270 SP IMR-4064 57.0 GR. 2380 FPS
300 SP IMR-4064 52.0 GR. 2110 FPS

Hope this helps or at least gets you started in the right direction. Hope you have some 4895 or 4064 on hand as well. Good Luck.