New to the 375 H&H

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.

Thank you all for your time.

Gunnie, Personally I only use Remingtom brass, only Federal Mag primers, and only IMR 4350, Max charge of 75 gr. Works for me,
I made a mistake once confusing powders so now I just use one and one primer for all my rifles (except my 223).

Gunnie said:

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.

Thank you all for your time.

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Hello Gunnie,

My most consistent accuracy (with more than one rifle) in this caliber has been with IMR 4350 powder, Winchester brass and Federal primers.

However, this cartridge seems to be relatively accurate with several powders also more than one brand of brass, primers and bullets.

Winchester brass is lately difficult to find in .375 H&H, at least it is so here in Alaska, where it was once very plentiful.

Personally, I have found it to last a bit longer before the necks split from reloading than Remington brass does.

Likewise, Winchester brass in this caliber supposedly has a slightly higher capacity, thereby operating at slightly less pressure than some other brands, all else being the same.

My favorite load is sort of mild (300 gr round nose at 2400 fps) and so, any minute difference in case capacity from one brand to the next is not important to me.

Plenty of folks strive for a rifle to put 5 shots into a one inch cluster at 100 yards and I used to be one of them.

However, as big game rifles go I quit worrying if they will put only 3 shots into an inch and a half or even two inches.

(Prairie dog/gopher rifles are best if they shoot tiny little groups and under a half inch is very nice for these).

Read your loading manual "Safety Warning" paragraphs with great interest and stick to what is written there then, you will do well.

Cheerio,
Velo Dog.

I still like my big bores to put bullets into less than an inch at 100 yards and I usually get them to do better than that.



The above target was shot at 200 yards with a handgun. The only bullets weights I've used in my 375 H&H Magnums have been 270 and 300 grains and the only powder I've used is RL-15. Primers have been Federal 215M or CCI 250. As for brass, Federal brass has a pretty poor useful life; may be one or two reloadings. I think Remington is better. What I like the most is Norma brass; it's a bit more expensive but it lasts longer.

You need to be introduced to Pheonix Phil on here..... He's pretty much the authority on this topic. Lots of other smart dudes to. I stick to premium store bought.....

Gunnie said:

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.

Thank you all for your time.

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You're in the hunt for sure I'd say.

250/260gr Projectiles : H4895 or Varget, my personal favorite is H4895 behind 250gr North Forks. But it works well with 250gr TTSX also.

300gr Projectiles : IMR4350 works awesome with North Forks, A-Frames and TSX

Varget is not prone to temperature change.

Gunnie said:

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.

Thank you all for your time.

Click to expand...

Hi Gunnie,
I've just gone through the exercise you are embarking on. My son and I shoot Blaser R93 rifles. Recently we both obtained our own .375 H&H barrels. We set about developing a load that gave the same results through both barrels. Chosen projectiles were Woodleigh Weldcore RN SN 300 gn and Woodleigh FMJ 300 gn. For everything we use Norma brass ( in my multi calibre experience by far the best reloading brass for longevity ). Primer CCI 250. We wanted 2500 fps mv for both rifles. We achieved this with AR 2209 ( same as H4350 I believe ) 79.50 gns and both rifles shooting very similar groups. Interestingly, other powders we tried Varget, RL 15, RL 17 gave significant mv differences approaching 100 fps but with all accuracy was reasonably good. I think the .375 H&H is just inclined to shoot well anyway. Our eventual load is one of the easiest we have developed for any calibre. We compared our load against Norma factory ammo - 300 gn Oryx projectile - and brother do our Blasers love that ! Absolutely no problem shooting sub 1 inch groups at 100 yds although 50 fps less mv. Best of luck with your load development. I hope you enjoy shooting this great cartridge as much as we do.

Seems like the majority of folks like 4350. I shall give it a try first hopefully it suits me as it has you gentleman. Thank you. Also will give Norma brass a try don't mind to spend money if I'm getting a high quality product.

Thank you all very much I appreciate the help greatly. Will let you know how it goes once weather warms up. 30°F average much to cold to shoot.

I have never failed to find a good shooting load at top velocity with 300gr and IMR 4350.

WW760/H414 are also worth a try if IMR4350 for some odd reason does not work for you.

I have a BRNO ZKK 602 in 375H&H that I've had for over 25yrs. I kept all my notes that I typed...yes typed on my typewriter way back. I had the latest electric typewriter in the early 80's! These loads were shot when the TRS 80 and Commodore 64 were becoming popular. My notes indicate that I had shot these during the winter when the temperature was a balmy & windy -3C to -12C....(invincible teenager!). Digital cameras were still on the drawing board, and I didn't have a chronograph.

Hope this helps

Hornady 270gr SPPT, 68gr's IMR 3031, CCI 250 Mag primers, Winchester/Western brass (didn't have the money for the good stuff) approx 2500fps. 5 shot 1.5" group at 100yds

Hornady 300gr FMJ, 77gr's H4350, WLRMP, W/W brass approx 2550fps. 3 shot 2" group at 100yds.

Hornady 300gr FMJ, 76.4gr's IMR 4350, CCI 250 Mag primers, approx 2500fps 3 shot 2" group at 100yds

Hornady 300gr RN SP, 77gr's H4350, WLRMP, approx 2550fps. 3 shot 1" group at 100yds. There wasn't much difference between the CCI's and Winchester Mag primers.

Barnes 350gr RN SP, 70gr's H4350, WLRMP, approx 2250fps. 3 shot 1.1" group at 100yds
My pet groundhog load: Hornady 220gr FLPT, 68gr's IMR 3031, CCI 250 Mag primers. I had a bunch of cartridges that I made up 25 yrs ago that I took to the range in 2013. The lead was white from age so these was old. The chronograph measured the average velocity of the 20 or so rounds at 2773fps. I was able to shoot a couple of strings of 3 shot 1/2" groups at 100yds. I put a target at 300yards and kept the rest within the 4" bull at 300yds.

I also played with Speer 235gr Sptizers, and Sierra 300gr BTSP's. They all shot well

Wow!!!! Impeccable detail. Nice!

BWH said:

Wow!!!! Impeccable detail. Nice!

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If you have not figured it out; Reloaders are nuts or just functional OCD!

71.5 gr H4895, CCI Mag Primers, Remington Brass behind a 250 grain TTSX.
The powder suggested as accurate by Barnes. Seems to work so far.

I'll be testing the theory at long distance this coming weekend when it gets warm enough to venture outside.

Gunnie said:

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.

Thank you all for your time.

Click to expand...

Gunnie said:

My new CZ 550 rifle is supposed to be here tomorrow. I'm hoping to start loading very soon. I have purchased two boxes of Hornady DGS for the mean time. Want to see with you fine gents on powder selection for the 300s. I already have a set of dies for it. Also will be using Winchester Primers.

I have looked in my hornady manual and would like to know which one you have had good luck with. My main concern is something that will be consistent in various temperature ranges.

I am considering H4895, Varget, Win760 and RL-15. I try to stick with one type of powder if possible I've noticed 4895 loads all the way down to 220s my plan as of now is to load all 300s but as you all know we handloaders just have to explore other areas.

What brass would you folks recommend also? I will be buying new brass so something that will hold up well to many reloadings is prefered.
I shot this group out of my Kimber Talkeetna model 375 H&H, I used Nosler Accubond bullets and reloader 17 powder
Thank you all for your time.

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I shot this group with my Kimber talkeetna 375 H&H, and the Accubond Nosler 300 grain bullet and reloader 17 powder.

I was just playing around with my 375 today working on bullet set-back, for my various bullet weights. it turns out most of my weights like H4895
270=h4895 59gs
250=h4895 57gs
235=h4895 69gs
300=w760 75gs
200=H380 78gs
Reloader 15 is also a great powder, but availibilty of certain powders limits experimenting
these have been start of loads and not near the Max loads you can go to. The Hogden sight is EZ to navigate and full of variations. As far as Brass and primers, I use what I can Buy at a decent price most of my brass is used

Good luck with it. I'm sure you'll be happy.......now to get you started on something larger so we can welcome you into the 40 cal & above Big Bore Addiction group....... Once that happens then it will be like choosing a chocolate from a box of chocolates...you gotta have more than one

BRICKBURN said:

If you have not figured it out; Reloaders are nuts or just functional OCD!

71.5 gr H4895, CCI Mag Primers, Remington Brass behind a 250 grain TTSX.
The powder suggested as accurate by Barnes. Seems to work so far.

I'll be testing the theory at long distance this coming weekend when it gets warm enough to venture outside.

Click to expand...

Just goes to show you the significant differences that Brass and rifles makes! With Nosler brass, 71.5gr H4895 with the same bullet is a highly compressed load that was showing signs of over-pressure in my gun (although it was accurate). With my Win M70 with 25" barrel I have recently settled on the following;

250gr TTSX
69.3gr H4895
Nosler brass
CCI 250 primer
2.960" to ogive (about 3.600" COAL)
very mild FCD crimp at bottom edge of first cannelure
velocity: 2,762 fps

What velocity are you getting with 71.5gr and the Rem brass?

Desert Dog said:

..................
What velocity are you getting with 71.5gr and the Rem brass?

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five shot average at 3800 ft ASL
2864 FPS

BRICKBURN said:

five shot average at 3800 ft ASL
2864 FPS

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Right in line with what I saw only 72gr of H4895 and about 1000' elevation.