What is the best powder for the .375 H&H?

[BlaserNut]

I've been shooting a Blaser 93 .375 H&H with 260 gr Nosler Accubonds loaded with 72 grains of RL-15 powder. My shots keyhole at 200 yds, so I've never wanted to mix anything up. Now that I can't get RL-15 I'm looking for a new powder. Does anyone have experience with large magnum bullets, good or bad, that can help point me in the right direction?

 

[06 SB]

Back when I shot a 375H&H, I used H4350 with a 260gr Nosler Partition and I4895 with a 235gr Barnes TSX.

 

[Edge]

Using H4895 in 250 TTSX but that’s another powder that’s become scarce. Using RL15 in my 300gr loads but I’ve set aside 3 or 4 pounds to hopefully get through this dry spell and can restock.

Hodgdon lists both H & I 4350s in the 260gr load data and available but no first hand experience.

 

[Choupique]

Trail boss !!!!!!!!!

That's all I've tried in mine so far (so fun with 200gr bullets), but I will be trying h4350, RL17 and IMR4895 come spring time.

 

[BlaserNut]

People I know around here, H4895 has been the most recommended to me followed by H4350, I'll likely default to one of those. Does anyone have experience with Norma203B?

Thank you everyone for your insight.

 

[Chupacabra]

H4350 and Nosler AB 260s is my recipe. I’ve shot the old school Hornady all copper (cx I think) and it didn’t group as well. This was through a Ruger #1 tropical. I will see if I can find my notes on speed. I wasn’t pushing them super hot though.

 

[pbroski]

H414/W760 has always worked well for me with 250 to 300gr bullets

 

[163bc]

RL15 has proven the mast accurate for me with 260-300 grain bullets.

 

[BlaserNut]

Chupacabra, if you find those notes, I'd love to see them. The more I look into H4350 the more it looks to perform very similar to RL-15.

 

[Compressedload]

Re15 is pretty good as is Norma 203B...same stuff? Many think so.

H4350 works but is bulky. Been trying SB 6.5. Seems like a great option so far.

 

[Compressedload]

What do you mean by large magnum bullets? Cartridges?

I shoot a lot of 350gr in my 375 H&H rifles... If that answers your question on bigger bullets!

 

[BjornF16]

Hodgdon data gives the nod to H4350 or StaBall 6.5 for better velocities. When I get my rifle back, I will likely use those for 260 gr bullet work up

 

[TheCoyote]

H4350, H4831SC would be good to try.
Could it be a twist rate problem?

 

[Fireflyfishing]

I use IMR 4895 and always have great results.

 

[BlaserNut]

What do you mean by large magnum bullets? Cartridges?

I shoot a lot of 350gr in my 375 H&H rifles... If that answers your question on bigger bullets!

My terminology there wasn't great. I was intending to I.D. high velocity heavier and larger caliber bullets. I would expect a 100 grain .243 to respond very differently than a 260 gr .375, to the same powders as their velocities and weights are so different. If I'm demonstrating my inexperience, I'd love to learn that too.

 

[RockAndSage]

My terminology there wasn't great. I was intending to I.D. high velocity heavier and larger caliber bullets. I would expect a 100 grain .243 to respond very differently than a 260 gr .375, to the same powders as their velocities and weights are so different. If I'm demonstrating my inexperience, I'd love to learn that too.

Part of what's going on includes how much more "overbore" the case diameter/capacity is over the bullet. I can't really give you the exact science, but in concept the closer they are, like with .308, .35 Whelen, or .375 H&H, the more benefit you get out of quicker burning powders. The more overbore, the more benefit from slower burning powders.

Heavier or lighter bullets in that same cartridge might mean a little slower or faster burning powder, but it's not as big of a difference compared to when you take that same diameter bullet and put it in a really overbore casing.

That's why you generally find quicker burning powders in .308 Win than you do .243 win, or between .308 Win and the big .30 cal magnums. The more overbore, the more benefit you generally get with slower burning powders.

Bottom line: It doesn't matter how big the caliber is, what's at play is a ratio between caliber to case capacity. The closer the ratios between different cartridges, the closer their powder needs will generally be.

 

[thinhorn_AK]

Reloader 15 and imr 4831.

 

[sololearn9]

IMR 4064 is my favorite powder for the .375 H&H Mag

 

[Yung6ix]

I tried H380and didn't like it.

I think i will be trying the suggest RL-15 next.

 

[CHWine]

Another vote for H414. You never hear people talk about it. One of my early hunting mentors got me using it for 7mm08 and its great in the H&H too. BTW I shoot 270 TSX.