I want some opinions on powder choices for 375 H&H using 300 gn bullets and Federal 215 Primers in a Win 70 with 24" Douglas Premium stainless 1:12 barrel. I have always liked IMR 4064 the best and also have some IMR 4350 on hand.

Win 760/H 414 works well for me for 300gr 375 H&H loads.

RL15 has a big following for the .375 also. But I think you will find that several powders will work well.

LWD

H-4350 (or the IMR version) will probably produce the best velocity. IMR-4064 is also a fine pwder but then as said.....many others are too.

My favorite powder for the 300 grain bullets is IM4064, for the 260 grain Partitions I use IMR4350.

RL-15 and don't look back. I got just over 2600 with it and 300gr. TSX's last summer. No pressure signs, but the velocity is a little spooky. Didn't think it'd go that fast. Think I'd back it down a grain or 2 to hunt with, but it was accurate as hell.

David

In Australia we use the ADI(Australian Defense Industry) AR-2209 for the 375H&H.
The ADI powders are well known not to react excessively to hot temperatures and is sold in the US as H-4350.

4350 is the classic powder for 375

Another vote for RL-15 and either 270 or 300 gr. bullets.

I have had good luck w/ RL-15 and Varget with 260 and 300 gr slugs...

In my M70 .375 H&H I found AA4350 to be a very good powder for the 300 and 350 gr bullets. It edged out Varget, RL15, IMR4350 and IMR4064. In R-P cases with WLR primers I use 79 gr under 300 gr bullets and 77 gr under 350 gr bullets. Velocity of the 300 gr (Hornady SPBT, RN or FMJ) run 2510 fps with 51,600 to 53,000 psi(M43). Velocity of the 350 gr (Woodleigh SP or FMJ)is 2375 fps at 55,000 psi(M43).

With the 300 gr SPBT zeroed at 200 yards the 300 gr RN hits to the same poi at 100 yards (2" high). The Hornady 300 FMJ and the 350 gr Woodleighs hit poa at 100 yards. Makes for a perfect zero without having the adjust the sights when switching ammo. Zeroes with your rifle may, of course, be different.

Larry Gibson

I load for 2 .375s, a Sako and a Interarms Whitworth. WW760 is the best powder I've tried in these guns with the 300 gr Noslers and Sierra BTs. Ditto with the 300 Hornady Solids. Velocities approach 2600 fps.

For lighter bullets (the 270 Hornady SP and the Speer 235 gr), I'm equally fond of IMR4320 and Re-15. All-in-all, this cartridge seems agreeable to most any sensible load, and I've found that its pretty easy to get 1 to 1.5 inch groups with both rifles.

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I found AA4350 to be a very good powder

Larry, I'm new to reloading... who makes AA4350? Also, what is the "M43" you are referring to when citing pressure levels?

Thanks
Mike

I switched from 4350 to WW-760 with 250 grain bullets simply because the denser ball powder allowed a little more powder and velocity. However, with 300 grain bullets 4350 would be my first choice as powder room would not be an issue.

I like Varget

My model 70 likes H-4350 the best. I tried RL 15 in it and a few other of my rifles (various calibers) and have found the only use I have for RL15 is to put a couple of spoon fulls in the wood stove in the morning to get the fire going.

VARGET is some wild stuff!! Fill the .222 family of cases with it(.204.222,223,222Magnum)wipe the case mouth off with your finger and fling the light grained bullets to your hearts content without worrying about pressure! Step up to the .308 based cases(.243, 260, 7-08 and 308) and somewhere between 36 and 43 grains is gonna fit real good! Step on up to the RSAUM or WSM and it's gonna fit real well again! Take it up to the ORIGINAL MAGNUMS like the 375 and just be amazed! Most amazing developement in powder since IMR 3031!!! Never thought I'd see a MORE VERSITAL powder than 3031 but then came VARGET!! ..............do they make it in 30 lb containers??? haha!! Charlie (GHD)

I really like R-15 in my H&H and .375 Ruger.

I got my sticky hands on to some canisters of IMR-4350, but mostly find data for the H-4350.

Are they the same powders, and can I use data for H-4350 when loading with IMR-4350?

I plan to use it for 270 and 300 grn bullets in my 375 Ruger African

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Are they the same powders, and can I use data for H-4350 when loading with IMR-4350?

NO! NO! NO! NO! NO! H-4350 and IMR-4350 are not the same powders. Even if I am dead wrong and they are even close to one another in burn rate and pressure produced, it is incumbent upon any reloader to always, always, always look up the loading data for the round he is using, to include bullet, case, primer, powder and charge. Never assume powders with the same number are the same powders if made by differing manufacturers. Your penance is to load 50 shells after having dutifully read and understood the rules for loading that particular round. Go shoot in peace and assume no more...

Rel 15 worked best for me, both with 270 & 300 gr TSX and Hornady bullets.

My TSX loads were easy to work up (with Rel 15)compared to the 270 WIN and 300 rcm loads I've worked on.

+1 for RL15 and the 375 H&H. It's pretty tough to find in AK, so I loaded 14 pounds (5 of which was RL 15)of smokeless powder on the back of the Harley and drove it to AK from CA.

Interestingly, I had to mail my pistol from Haines, AK because Canada wouldn't let me cross the border with it; however, I could traverse the Yukon with 14 pounds of smokeless powder and 1000 primers. I see Canadian law makers are as bright as ours in the US. Lou

I loaded 300 grain TSX with Vihta N140 for a buddy who went to his big safari in Tansania. He was very pleased with both precision and performance.

quote:

Originally posted by homebrewer:

quote:

Are they the same powders, and can I use data for H-4350 when loading with IMR-4350?

NO! NO! NO! NO! NO! H-4350 and IMR-4350 are not the same powders. Even if I am dead wrong and they are even close to one another in burn rate and pressure produced, it is incumbent upon any reloader to always, always, always look up the loading data for the round he is using, to include bullet, case, primer, powder and charge. Never assume powders with the same number are the same powders if made by differing manufacturers. Your penance is to load 50 shells after having dutifully read and understood the rules for loading that particular round. Go shoot in peace and assume no more...

What I was assuming, not the same.
A bit confusing though as a few sources just say 4350, among them my old Hornady Handbook Vol II. Hard to tell which 4350 they are refering to.

I´ll start low and see what happens then...

Check the Hodgdon load data center which you can access from their website. They should have some data for both the H and IMR versions.

LWD

Try H 4895 - use it in many calibers and gives great accuracy.

Hello,

In my experience, any of the 4350 are the powder of choice for 300 grs bullets in the .375 H&H. I use 80 grs of IMR or Accurate 4350 for 2550 f/s in my M 70 Pre-64. Around 100 % load density. Very consistent and trouble free load.

Regards,

PH

Arild, most of the "older" reloading manuals referencing 4350 will be for IMR. Hodgdon now owns IMR and has loads for both the H & IRM powders on their website. H4350 is similar but NOT the same as any of the other 4350's made by other companies. Always verify b/4 using.