IMR3031 load data for 375H&H?

[Longwalker]

Rookhawk, when I offered my advice on this topic, I didn't realize the advice could be used to interpret the question above. I thought you were looking for reduced / low recoil loads for practise and hunting smallish game like deer or plains game. Now the topic is defined as dangerous game hunting with reduced loads and solids. That makes me nervous.
To determine minimum effective loads for big, dangerous game animals, I think it would be more appropriate to look at standard or normally accepted cartridge recommendations for the answers you seek.
When some African countries legislated a minimum of .375" for dangerous game, those recommendations were made with standard factory loads in mind. .375" 300 gr. / 2500 fps. I think there has been enough historical success in the field to seriously consider a slightly lower standard as "adequate". But only slightly lower. The 9.3x62 and 9.3x74R are the bare minimum most reasonable people would consider "adequate" for hunting big dangerous game. 9.3mm 285gr. / 2350 fps. Sectional density of that 9.3mm bullet is the same as the .375/300gr. Penetration would be similar at similar velocity. So the 9.3's factory loads penetrate just slightly less than .375 factory loads.
Of course many elephant have been shot and some even killed cleanly with 7x57 and .303 and .308 and even heaven forbid, 7.62x39MM. That's besides the point.
All this is a judgement decision. If I was loading a .375 for shooting something that required a solid, I wouldn't load it any lower than 260 gr. / 2500 fps. But heavier & or faster = better.
Whatever the load, it would be important to have the approval of the professional who will guide the hunter.

 

[rookhawk]

@Longwalker I appreciate your input. The proven recipes as you say were really well established with the large bores. Anything leaving the muzzle at 2150fps, hitting an animal above 1900fps, with a bullet over 400gr and over 40 caliber, will kill anything, everything, and with authority. (Assuming a good shot)

But the goal of this post isn’t really a diminished load as in, some plinking load. Rather, it is an “efficient load” For a medium bore 375 which is a bit more murky.

In my double rifle at regulation load velocities, I can shoot either a powder that produces 90lbs of recoil, or 58lbs of recoil, but either way my .470 regulates and is sending a 500gr solid at correct speeds.

I’m trying to find a similarly efficient load for my son’s .375HH. It appears that 3031, 4895, and RL15 will provide equal performance with about 20%-25% less recoil than other “normal” powders.

It looks like a very harsh kicking 300gr Federal factory load at 2440fps could be made with 40% less recoil if it were a 260gr bullet with an efficient powder. Still same bullet density, same bullet diameter, same velocity.

 

[Wyatt Smith]

Rookhawk, the 9.3mm 300 grain swift A frame is just the 375 bullet sized down to .366. People seem to like them at 9.3 62 velocities. The late Bruce Moulds really liked them in his 9.3x64 even at longer ranges where the speed dropped down.
The 300 grain swift loaded at 2300 might be a very good compromise.

 

[Longwalker]

Ok I understand better. Thanks for the explanation. Someone with much more experience than me would be better answering your question. From my uneducated and inexperienced perspective, a 260 gr. Solid cannot be expected to do the same job as a 300 gr. Solid. It won’t penetrate as deep.

 

[rookhawk]

Rookhawk, the 9.3mm 300 grain swift A frame is just the 375 bullet sized down to .366. People seem to like them at 9.3 62 velocities. The late Bruce Moulds really liked them in his 9.3x64 even at longer ranges where the speed dropped down.
The 300 grain swift loaded at 2300 might be a very good compromise.

@Wyatt Smith 300gr A-Frame at 2300fps would output only about 31lbs of felt recoil. That’s a lot of power for pretty darned moderate recoil. Off shooting sticks, it would probably feel similar to a 12 or 20 gauge 2-3/4” load.

 

[Wyatt Smith]

I have plenty of 300 grain bullets (not swift, the recoil should be the same) If you want to try a few and see how he likes them.

 

[Shootist43]

Rookhawk, I'm not sure if I can answer your question to your satisfaction. But let me relate an answer I got several years ago. My son's Bergara barrel for his 35 Whelen "crashed and burned" and he was forced to use his 300 Win. Mag. Available bullets were the 180 and 200 grain Swift A Frames. I asked a very notable PH which of these two would be best. His answer without hesitation was the 200 grain, which of course had a lower velocity. The only difference is that we were hunting PG and not DG. Apart from that, we all know that the "Bell" of elephant hunting fame used a 275 Rigby / 7 X 57 to kill elephants. We also know that it wasn't his preferred caliber.

 

[fourfive8]

FYI, Graf has 375, 300gr PPU-PRVI soft points in stock at reasonable price and flat rate shipping. They must have procured a huge pile of them a couple years ago. For practice and range time, that’s all I’ve been shooting. Accuracy seems very good and no surprises when reloading.

For purposes outlined in this thread, I’d be tempted, unless forced otherwise because of availability, to simply develop a slightly reduced load with a good 300gr softpoint.

It’s easy to overthink these things

 

[Tanks]

...
On large, dangerous game, using solids, what is the key cause of death using a 375HH?...

The animal starts laughing so hard after being stung by it that it chokes to death?

 

[Tanks]

Seeing that you reload may I suggest building a .50 B&M Super Short. @michael458 had built one for his young (at the time) daughter that she shot very well. Accurate Innovations stock with patented aluminum bedding does reduce recoil significantly.

Details here.

50 B&M Super Short

50 B&M Super Short

www.b-mriflesandcartridges.com

 

[rookhawk]

Seeing that you reload may I suggest building a .50 B&M Super Short. @michael458 had built one for his young (at the time) daughter that she shot very well. Accurate Innovations stock with patented aluminum bedding does reduce recoil significantly.

Details here.

50 B&M Super Short

50 B&M Super Short

www.b-mriflesandcartridges.com

Fun little cartridge. A bit too wildcat for me though. I've always wanted a "baby mauser" in a fun caliber though. I think Zastava and Rigby both made this tiny little action even smaller than a Kurz? How fun to have a stalking rifle that weighs 5lbs scoped with high quality finish and wood?

 

[cal pappas]

Just started loading and shooting my new 375 Interarms Whitworth this past week. Using 3031 and 270 grains bullets and all seems to be well.

 

[Ray B]

The initial push of recoil can be calculated for the closed system of the rifle. When the loaded cartridge is in the chamber the rifle will have a specific balance point. When it is fired, just prior to the bullet leaving the barrel the balance point will have changed- due to the bullet now being at the muzzle and the powder charge being distributed somewhat evenly in the bore. The change in balance point will be the distance that the rifle wants to move. the duration of time taken for the bullet to travel from breech to muzzle is the time taken by the change. Heavier bullets change the balance point more while faster bullets cause the change to be quicker.

Then the bullet leaves the muzzle and you get the propulsion effects and the momentum of the rifle.

 

[rookhawk]

@Ray B no idea how bullet weight changing balance of the gun could be relevant or felt? A 10lb .375HH using a 300gr versus a 230gr bullet? The latter is 1% of one pound less weight than the former. What change in balance will occur when something 1% of one pound reacts to something ten pounds?

 

[small bore]

Hi Rookhawk, Your question about loads for 375 H&H using IMR 3031 rang a bell. Rummaging around the shelves finds loads in Lee's 2nd ed., Lyman's 50th ed., Sierra's ed. VI manuals and also online from Speer. Anything in particular you're interested in from the manuals?

 

[rookhawk]

Hi Rookhawk, Your question about loads for 375 H&H using IMR 3031 rang a bell. Rummaging around the shelves finds loads in Lee's 2nd ed., Lyman's 50th ed., Sierra's ed. VI manuals and also online from Speer. Anything in particular you're interested in from the manuals?

Hi @small bore , IMR3031 is a fairly low recoil load, works in virtually every classic safari caliber, does not have ill effects in lower charge weights provided dacron filler keeps the powder pressed against the primer, and its the closest powder to the original cordite most guns regulated with initially.

For those reasons, I really wanted to find a 270gr and 300gr loads in various ranges for use with 3031. If you see any in your vintage reloading manuals, I’d appreciate if you could post the info.

 

[Tanks]

@Wyatt Smith 300gr A-Frame at 2300fps would output only about 31lbs of felt recoil. That’s a lot of power for pretty darned moderate recoil. Off shooting sticks, it would probably feel similar to a 12 or 20 gauge 2-3/4” load.

BTW, that is the load (bullet weight and velocity) of a 375 H&H flanged magnum. It has been sufficient in the right hands, and as you said minimal recoil.

I'd explore loads with that approach. Unfortunately, I don't have any data.

 

[small bore]

As requested by Rookhawk here is a partial summary of published data for loads using IMR 3031 in 375 H&H Magnum.

From Sierra for their 250 gr. SBT start @ 58.0/2500fps and up to max 66.4/2800fps. For their 300 gr. SBT start @ 57.3/2300fps and up to max 62.2/2500fps. (Sierra Manual ed. VI)

From Lee for 270 gr. jacketed bullets start @ 57.6/2327fps and up to max 65.5/2610fps@53,000 CUP. For 300 gr. jacketed bullets start @ 56.0/2220fps and up to max 63.0/2465fps@52,500 CUP. (Lee Manual 2nd ed.)

The data from the other sources I mentioned in the above post are for bullets of 200 and 235 grains from Sierra and Speer respectively.

Rookhawk- if you pursue development of these loads I'd be glad to hear all about your work.

 

[rookhawk]

Well, I just wanted to put a wrapper on this thread and report favorable results. In the end, I found a lower recoil load that was suitable for 375HH using IMR4895.

These are the loads:

Qual-Cart Brass
IMR4895 - 63gr
260gr Nosler Accubond
Federal 215 primer

Qual-Cart Brass
IMR4895 - 65gr
260gr Nosler Monometal Solid
Federal 215 primer

Both loads were at or just above 2400fps.

The loads according to the math I was using, while slightly diminished, were pretty much spot-on for a full magnum load equivalent in a 9.3x62mm. Recoil in my son's gun was between 24-26 foot pounds of felt recoil. He brained a 12' croc (a confirmed maneater) without much fanfare and was able to shoot it off sticks and freehand with no issues whatsoever. He dropped a nice kudu with it in one shot as well. He never saw any elephant so we didn't test that out but it would have performed just fine I'm certain.

This will be his go-to load until he's ready to step up to 270gr and 300gr monometal solids and TTSXs in a year or two. (another 8lbs of felt recoil in the process)