Almost Ready To Load For The .375 H&H

Mumbles Marble Mouth

Mumbles Marble Mouth

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I picked up a bunch of brass in the mail yesterday (Thanks you very much Douglas!) I also happened to pick up today a set of .375 H&H Dies as well as shell holder.... dammit I forgot the shell holder plate for my case trimmer..... and a 37cal pilot... So other than that, all I need it powder and bullets. Was hoping some of you guys could share your favorite powders and bullet combinations for the .375 H&H. Also, how long do .375H&H cases last? I cut my one federal brass case I had in half to see how thick it is and they're way thicker than my .270 win brass. Just asking because I always just picked my .270 brass up from the range buckets, shot them twice, then tossed them. I've collected about 500 brass cases for the .270 from range buckets so I was never really concerned about extended brass life. Now that its a .375 H&H I feel very concerned with extended brass life. Tips and tricks on that topic would be great as well.

So far I'm thinking of starting off with the left over IMR 4064 I have and Hornady .270gr Interlocks to just get started shooting the gun however I will like to make a more serious load for hunting later.
 
Brass typically fails in one of three different ways. They are, with mitigation suggestions:

1. Neck Cracking

Every time you fire, the neck expands to fit the neck in your chamber. When you resize it with a standard FL die (which it looks like you have in the RCBS green box), the neck is reduced significantly below final needed size. Then it is expanded back up with an expander ball. This whole cycle fatigues the neck brass and eventually results in a longitudinal crack. If you use a bushing die, or have the neck in your custom die opened up you can reduce the extent the brass is worked. Or you can accept the working of the brass and anneal it to soften it back up again before it cracks. Best to do it after 5 firings. Since this is a cartridge that I suspect will not be fired many thousands of times, that is probably your best solution.

2. Case Head Separation

Belted magnums can crack around the circumference just up from the belt. Brass thickness does not help. It is caused by resizing the case so it is too short, and then stretching it every time your fire it. The solution is to get a Hornady Headspace Gauge and measure the case from the base to the shoulder datum point after firing, and only resize it back a couple of thou maximum.

3. Primer Pocket Enlargement

If you run too high a pressure with your reloads the head will expand, and the primer pocket along with it. At some point you will not be able to keep the primer in the pocket, and the case is toast. Obvious solution is to not overload.

Hope that helps some,
 
In 30 years of reloading for the 375 I have never split a neck, brass last 6-8 reloads with full power loads and you can see where it will separate. I full length size only. Never enlarged a primer pocket. IMR 4064 has always been the go to powder.
Reduced cast bullet loads for practice and neck sized with a lee collet die, brass seems to last forever.
 
For full power hunting loads RL-15 seems to be popular, anything in 4064,Varget range will work for everything else. 375 hoot&holler is not fussy about what works! As mention before don't oversize your brass and it will last a while.
 
244Ack said:
In 30 years of reloading for the 375 I have never split a neck, brass last 6-8 reloads with full power loads and you can see where it will separate. I full length size only.
Click to expand...

My benchmark for good case life is 20 reloads. If you are seeing a crack down near the belt, that indicates you are bumping the shoulder back too much.
 
Fairly new to the .375 H&H Magnum and haven't done a lot of reloading for it. I follow the load data in the Woodleigh Bullets Loading Manual for 300gr bullets at around 2350 fps MV using Reloder19.

375%20HampH_300grWDY_300grAB_270grTSX_zpswsvoyj3e.jpg

L to R: Woodleigh 300gr PP SN, 300gr AB, 270gr TSX

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Sako 85 Kodiak .375 H&H Magnum with Leupold Ultralight 3-9x33mm scope
 
My reloading manuals mention that after 5 case trimmings you should toss the brass. That's 5 times X amount of brass removed, that brass flows from the web area of the case head and create a narrow ring of thinned case wall which will eventually crack through.
How much brass you remove on each trimming makes a difference on case life.
I did 6 firings and got worried about the tell tail bright ring appearing so I cut a few cases length wise to check on the depth the ring.
I tossed the bass as one more firing probably would have separated the case heads.
I just neck size my 375H&H brass and test chamber the sized cases prior to reloading them. For hunting cartridges I'd try for 1 to 2 thou. shoulder set back.
 
Greenjoytj said:
My reloading manuals mention that after 5 case trimmings you should toss the brass. That's 5 times X amount of brass removed, that brass flows from the web area of the case head and create a narrow ring of thinned case wall which will eventually crack through.
How much brass you remove on each trimming makes a difference on case life.
I did 6 firings and got worried about the tell tail bright ring appearing so I cut a few cases length wise to check on the depth the ring.
I tossed the bass as one more firing probably would have separated the case heads.
I just neck size my 375H&H brass and test chamber the sized cases prior to reloading them. For hunting cartridges I'd try for 1 to 2 thou. shoulder set back.
Click to expand...

1. You should get way more than 5 reloads from a case. After 5 firings you may want to consider annealing the case necks and shoulders, but I sure would not throw them away.
2. In no way does trimming the case for length reduce the life of the brass. You may have the cause and effect interchanged. If you are having to trim a lot of brass, you may not be preparing the case as well as you should. Perhaps bumping the shoulder too much.
3. If you really only bump the shoulder back 1 to 2 thou or just neck resize, you should get a long life without cracking down near the case head. I have gotten 20 firings from .264 WM brass. They failed with cracks in the neck, and I have never had any crack near the belt. Are you sure you are measuring the bump accurately?
4. If you worry about cracking near the case head, just bend a piece of wire 90 deg near the end to make a hook. Run it up and down the inside of the case near the head to check for a thinning spot. Reject the ones that are getting too thin. However if you minimize the bump, they really should not thin in this area. Here is a short article by German Salazar on the issue, although he does not talk about how to prevent it.
 
3M..........Don't believe everything you read on these threads written by self proclaimed "experts" because a lot of it is pure BS. Size your case until it fits your chamber snugly as in you can feel the tension as you cam down your bolt and go shooting. My pet load is RL15 and 270 gn TSX with a CCI 250 spark plug. I do trim all my cases to the same length after initial firing and I crimp my loads because I hunt with my 375s. They get handled a lot and thrown in glove boxes and consoles and pockets and my rifle really likes this load when crimped. Also my rifle is not particularly heavy and the recoil is quite sharp, considering I'm getting over 2900 fps from this load in this rifle, so I don't want to drive the bullets back in the cases. When hunting in Africa with this rifle and load, the same cartridge may be at the bottom of the magazine for 2 weeks and 50 shots so it is subjected to considerable abuse. If and when I may need it I don't want the bullet stuffed down hard on the powder and seize up my rifle when it goes BOOM.
 
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