AA5744, H4227 - low recoil 375 H&H

[Fryeguy]

Too much poor advice surfacing in this thread. Messing around with reduced pistol powder loads in large capacity cases under jacketed bullets is asking for trouble. No way will a properly prepared and loaded case with proper primer cause a delayed fire in an 80% H48965 load. That sounds like a straw man argument. Proceed as you like but not with any recommendation from me.

Also, Trailboss is a very specialized and bulky/low density powder. That does not mean it is a slow or forgiving powder either. It is a very fast burning, high energy powder, best used in cast bullet loads in high expansion ratio cases and not at all for jacketed loads in large volume, shouldered cases like the 375 HH. Again, proceed as you desire, being warned it may be based on questionable advice!

Here's a link to the 60% Hodgdon data

https://hodgdonpowderco.com/wp-content/uploads/2023/04/h4895-reduced-rifle-loads-2.pdf

Sorry, but I think you missed my point about light loads and H4895. It served as a warning with it, not poor advice. I think this load stuff is for much smaller volume cases, not necessarily a fairly straight walled, large volume case like the 9.3x74R. It may also be the same way with a large case like the 375HH. I had to look up my data from those incidents. It was 2 delayed firings, not all that I loaded did, but after the second one I stopped, went home and pulled the bullets. I was using Norma 232 grain Vulcan bullets, h4895, 48.0 grains. The data from a Lapua load manual for 9.3x74r is attached, for a 286 grain bullet. Using their data for a 286grain bullet (54.9grains max x 60% would be 32.94grains). One would think that 48.0 would’ve been perfectly fine for a 232 grain bullet, as a reduced practice load. I know the bullet has less weight it is also a shorter bullet, but this doesn’t account for 16 more grains of powder being used. It’s just too much volume in this particular case. Same for RL15 in 470ne cases, and I should have used a filler. Just a warning to be dang careful light loading even thou there is data on a particular powder for generic circumstances.

I guess best advice for OP, the best thing to do is pick a bullet that’s the lightest you may want to use, and call the manufacturer for reduced load data for 375.

 

[Fryeguy]

This is from latest Sierra manual I have.

 

[Kenn Loch]

Well, turns out my bathroom scale was on the fritz due to low battery…and I know cause the next day I weighed 161…I wish. Using a creative “double end” approach with a 6lb kitchen scale and then rechecking with a bathroom scale with new batteries. The loaded gun with scope weighs 9.5 lbs…mo better.

 

[Bert the Turtle]

Nothing wrong with shooting reduced loads. I don’t know why anyone is giving you the advice to only shoot full power loads. This hobby is supposed to be fun.

 

[Nevada Mike]

I called Hodgdon's for advice on reduced loadings for 5744 in my 404J practice rounds. They were very helpful and I load 35 - 37 gr for about 1800fps with 400 gr. cast bullets. it's accurate, safe and requires no buffers.

I am also using it for fireforming brass.

 

[Kenn Loch]

4227 has come back in stock (Midway USA and Grafs). Bought two lbs. Looking forward to loading some 235 grain bullets this weekend…shooting for 2,000fps or less with around 35gr of 4227.

 

[Bush Buck]

4227 has come back in stock (Midway USA and Grafs). Bought two lbs. Looking forward to loading some 235 grain bullets this weekend…shooting for 2,000fps or less with around 35gr of 4227.

Hi Kenn,

When I first bought a 375 I did a lot of shooting with reduced loads and I think it really paid off in terms of becoming very familiar with the rifle. I shot hundreds of these loads from a variety of field positions including sticks. I practiced with heavier loads before my plains game hunt and everything went very smoothly in Africa.

The following is what I did with my rifle. You'll need to do your research and work up loads to figure out what's safe and appropriate for your rifle.

I used IMR 4227, Federal 215M and Speer 235 gr.
I read that gun writer John Barsness used 220 gr over 35-37 gr of 4227 to prep for Africa.
I read something in American Rifleman and the author used 225 gr over 36 gr 4227
I loaded a couple grains higher than this with careful work up and saw no pressure signs.
I do think the hotter Fed 215 primer was better with these small charges. I switched to these early in my work-up and never changed.

Important!
Like many reduced loads there is a risk for both an uncharged case and a double charged case!
I load in a tray and look into every case with a flashlight to make sure they all look the same before I seat bullets.
When shooting I use targets that allow me to see every bullet hit the target before I shoot again.

Good luck with your 375!

Bush Buck