I'm building a .375 H&H Ackley Improved-40. Anybody willing to share their favorite loads. I plan on using the 260 gr. Accubond and 300 gr. Nosler Partition for both elk, big bears, and African big game, including cape buffalo. Thanks ahead of time for any help. Regards, AIU

PS. I'd like to put a crimp on bullets - they have cannalures. I have Redding dies, but haven't figured out how to do it. Anyone know?

AIU, Load Data.com has 29 loads listed using 270 and 300 grain bullets with IMR 4350 and N 205 or 204 powders. I am in the process of working up some loads for a pre-64 Win super grade .375 H&H IMPROVED I'll be taking to Zim in June this year. I too have Redding dies. I'll be happy to swap results with you once I get them.

quote:

Originally posted by Ackley Improved User:
I'm building a .375 H&H Ackley Improved-40. Anybody willing to share their favorite loads. I plan on using the 260 gr. Accubond and 300 gr. Nosler Partition for both elk, big bears, and African big game, including cape buffalo. Thanks ahead of time for any help. Regards, AIU

PS. I'd like to put a crimp on bullets - they have cannalures. I have Redding dies, but haven't figured out how to do it. Anyone know?

Get a lee factory crimp die .375 H&H works like a charm & abuot $8.00 I will see if I can find some of my load data.

Sorry, can't help you on the .375H&H Imp. - but I like your choice of bullets!

I'm with tsturm.....buy a Lee Factory Crimp Die in .375H&H and be done with it.

IF for some reason the 40 degree shoulder won't work with a regular vanilla-flavored .375H&H shoulder, then Lee will custom make one for you for a coupla bucks more.

They are the best thing since sliced bread - easy to use, adjust and you get a "Factory" Crimp where the ammo will stand up to pretty much about any recoil level - cool!

These are MAX loads in my .375 H&H A.I.
WW brass, Fed 215 primer, Hornady 300gSp, 88.5g IMR 4350, Oehler-33 @10' from muzzle, 10 shot average 2774fps. I cant find any chrono. data for the 270g sp, load was 81g IMR 4064, 270g Hornady sp, WW brass, fed 215, I believe it was right at 2900fps ? Great Cartridge!!

DONT START WITH ANYONE"S MAX LOADS, start 10-15% lower & work up

I have been shooting a 375 Improved with 25 degree shoulder made by Bill Steigers for almost 25 years. The Ackley has just a tiny bit less powder volume.

My favorite loads with a Bitterroot are 92 grains IMR 4831 for Bills 300 grain and 94 grains for the 275 grain.

WW fire formed brass and Fed 215 primer.

This gives me 2800 fps with the 300 and 2975 fps with the 275.

You will probably have to reduce powder charge 2-4 grains for other makes of bullets. The Bitterroots have a 6 caliber ogive (which reduces bearing surface) are short for weight (pure lead) and being well annealed, are quite soft.

This sounds like a high pressure load but are not. You will bulk out the case before getting into trouble. I have to use a drop tube to get that much 4831 in there.

Andy

I shot the 375 AI for around 12-14 years. I settled on 87,0 IMR 4350 with the 300 Nosler for 2742-2768 depending on the weather.
With the 260 AB I used 91.0 H4350 for 2898-2932. My 375AI has a 24" barrel. WW cases, F215 primers.

Now I'm shooting a Ruger 77 RSM. The magazine and throat are long enough (3.73-3.78 OAL) that I'm within 1.5 grains of powder capacity compared to my AI. I have 1" less barrel length on the Ruger (23") and it crono's within 43-76 fps of the AI seated to 3.6 OAL (depending on the weather).
In both cases I can shoot my brass at least 8-10 shots. I believe good brass life in a magnum is one of the best indicators of pressure.
All speeds are with a Ohler 33, 10' from the muzzle.