This will probably strike you as a dumb question; but I would appreciate any advice on it from those of you who handload for the .375 H&H.

I have been handloading for a few years now, but I just bought a CZ 550 Safari American in .375 H&H, and so I have only recently started handloading for that cartridge.

The rifle is scoped. In working up loads at the range, I tried three likely powders (IMR 4350, Win 760, and Reloader 15) and two bullets (Hornady 270 grain and 300 grain spire points). So far, groups have been huge (2 1/2" to 5") except for one combination where groups were acceptable or better - 300 grain Hornadies with 75 grains or 76 grains of IMR 4350). I could be happy with one good load; but my question is this: should I assume that the rifle has a problem and needs bedding or other accuracy work; or is it just characteristic of this particular cartridge that groups with most powder/bullet combinations produce very poor groups, and that only one or two such combinations produce small groups?

It is to early to assume anything until you try more bullets. You may even try more powders, you have not mentioned primers and brass. All are variables that could make a difference. All I can say is keep shooting and loading, if the groups shot already are uncharacterically large for you. Good luck and good shooting.

quote:

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Originally posted by BigBrass:
I tried three likely powders (IMR 4350, Win 760, and Reloader 15) and two bullets (Hornady 270 grain and 300 grain spire points). So far, groups have been huge (2 1/2" to 5") should I assume that the rifle has a problem and needs bedding or other accuracy work; or is it just characteristic of this particular cartridge that groups with _most_ powder/bullet combinations produce very poor groups, and that only one or two such combinations produce small groups?

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My 375 shoots pretty well with just about anything I put through it, but found that IMR 4064 behind 300 gr. Sierras or Swift A Frames shot under moa. Nosler partitions shot well also. My groups got smaller as I worked toward the maximum listed loads (and beyond) in Sierra manual. Even above maximum loads did not produce quite max velocities in my barrel, so work up slowly!

Does the rifle group w/factory ammo?

Regards,
hm

Although every rifle is different, I have found that the 375 H&H is one of those cartridges that is not particular about the load that goes in it. It seems it is like the 30-06 - just about any reasonable combination will yield acceptable results.

phurley5, hm1996 and rcasto:

Thanks for your suggestions, guys. I suppose I agree with phurley5 that it is too early to panic, and that more powders and bullets should be tried. I am assuming, though, that if a rifle is extremely picky and shoots unduly large groups with a lot of different combinations, it is an indication of some accuracy problem with the rifle (which might be improved by some accuracy work), even though there is one particular combination that produces acceptable groups.

hm1996: Thanks for your suggestion; I will try the IMR 4064. I also intend to try Reloder 19 and IMR 4831. (I have room enough in the magazine to seat the bullets long, so I can use slow bulky powders like 4831.) I haven't tried factory ammo in the rifle.

I have the same rifle CZ550 American, 375 H&H. 2 inch groups at 200 yards with 73 grains of RL15 and 260 grain Nosler Partition (seconds). 74 and 75 grains very slightly bigger, but could be statistical variation due to small sample size.
Peter.

These are a few groups I have with my Mod. 70 Safari Express and Whitworth. Velocity around 2400 range 100 yards. Nosler Partitions and Accubonds. Both factory seconds from Nosler's Shooters Supply





I'm happy with these groups.

Peter: Thanks for your information. Did you have to make modifications to the rifles for accuracy in order to get those 200-yard groups?

Rusty: those are indeed excellent rifles . I will try the Accubonds and Nosler Partitions. Did you have to run through a lot of powder-bullet combinations that gave unacceptable groups before you found the loads that worked? And did you have to epoxy-bed those rifles to get those good results?

I have 5 375's ( I kinda like them ) and ALL shoot less than 1" with most all loads. I have a stainless M70 in a David Miller laminated stock that has shot a 20 shot group (yes I mean 20 rounds) that was .7 at 100yds. The action and barrel are fully glassed. The load was 75grs of IMR4350. I have taken everything up thru Buffalo with this with absolutely no problems. It is my favorite plains game load. This gun also shoots 300grs almost as well loaded up to the high side.

Rusty,

Nice groups.
I just bought a Left-handed 70, in 375, like the one you show in your photo. Did you have do do anything extra to get the gun to shoot those groups. My gun is mighty rough when it comes to finish. Bought it new, sight unseen, from a gun shop in Oregon. If I would have viewed it first, might not have bought it. I grabbed it up as finding left-handed 70's, in 375, are few and far between.

Anyway, hope it shoots as well as yours.

Roger QSL

My rifle is definitely not a tack driver per se, but it gets pretty good hunting accuracy...



I have also had pretty good luck with RL 15 and Swift A-frames (but no pic's handy). The Hornady 270 SP is not bad either. I have some 260gr GSC HV's that I am itchin' to try.

Cheers,
Canuck

I can see that there a a lot of .375s out there that shoot pretty good or excellent groups with the right loads, just as I had supposed there were.

I have been handloading for a few years for the .270, the .300 Win Mag, the .338-06 and the .45-70. With most of my rifles, I get so-so groups until I find the right combination. Even though I haven't tried many powder-bullet combinations yet, I think the fact that I get pretty bad groups with the new .375 - except for that one combination - tells me that there is probably some bedding or other accuracy problem. More work for my gun smith, probably!

The only thing I did to my rifle was to have it rebeded by Jeff Smith. The load information I started with was supplied by Jeff from his Quick Load program.

I have to admit it was very close to as advertised! I asked for some RL15 loads for 260 grain Noslers.

If any of you would like it I saved the email and would be glad to forward it to you.

Just drop me an email rkmojo@aol.com

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Originally posted by rcasto:
Although every rifle is different, I have found that the 375 H&H is one of those cartridges that is not particular about the load that goes in it. It seems it is like the 30-06 - just about any reasonable combination will yield acceptable results.

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Ditto for me.

BigBrass, haven't done a thing to my rifle except adjust the trigger to remove just about all the take-up. It is VERY light. No bedding, no freefloating no nothing!
Canuck. I have some of the GS 260 FN's is that what you meant or did you mean the HV's? I have some of the 240HV's. Haven't tried them yet. Wanted to work up a load with the solids first.
Peter.

BigBrass - If it were me and I were getting bad groups right out of the box, I would get it bedded, do the trigger job and then try IMR 4064. 4064 is one of those powders for 375H&H that seems to always yield acceptable results. Unless there is some other problem, I can't help but think it will shoot with 4064.

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Originally posted by Peter:
Canuck. I have some of the GS 260 FN's is that what you meant or did you mean the HV's? I have some of the 240HV's.

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I have a couple boxes of 260gr HV's, ca. 2002. I got them for a trip to RSA in '02 but they didn't make it in time. I hope to work up a load with them in the next few weeks and use them in RSA this June.

Cheers,
Canuck

BB,

I agree with want phurley advised.

I also have a CZ 550 375 and before I shot the rifle I had it bed and cross bolted. The cross bolt probably has not necessary but it will be helpful to bed the rifle.

I only had time to work with the 270 grain Barnes TSX before I took the rifle to Africa. I used H4895 (since I use this same powder in my 458 Lott it made since to try in the 375). The load I used in Africa consisted of Norma Brass, Federal 215 Match Grade Primers, H4895, and the 270 grain TSX. At 100 yards groups were 1/2 moa, velocity was nominal 2720 fps.
I used as my light rifle taking a Zebra and Heartebeast with one shot each 120 to 200+ yards...penetration was fantasic... It worked very well. I will give the 300 grain TSX a try down the road.

My suggestions...Have the rifle bed and give the Barnes TSX a try.

BB,

Forgot to say...I also had my trigger adjusted on the 375....that may also improve groups...Good luck JJS

Thanks for your help, guys.

Glass bed the action, free float the barrel and get on with life.
You won't regret it.

Been there and got the T-shirt. Mine was a Remington 700, .375 Classic. It didn't shoot groups, it shot patterns! I tried everything, change brass, primers, powder, bullets, scopes, mounts, free float, full bed, pillar bed, etc. The final outcome? Bad factory barrel. Remington said it shot within "specs", but it was without a doubt the most inaccurate rifle I ever shot. I now have the rifle in the corner, pending a new barrel, bought a CZ LUX, .375 and it is a "one holer." I guess every company has lemons that do what our rifles did. I just wish they would stand behind correcting an obvious defect.

My browning 375 would not group well no matter what bullet powder combo, I ended up sending it back to the factory, they returned the gun in ten days and the gun would group 1" or less , I took a close look at what was done to it and all I could find was a little grinding on the synthetic stock at the rear mounting screw/
My recomendation
Make sure you have a good scope
good or better bases
good or better rings
make sure every thing is tight
bed the action
this should get you respectful groups
handload with different powder bullets to fine tune

Bigbrass, How does she shoot using open sights, may be your scope or mounts are the problem, My Win 375 can stick 6 rounds into the 1" at 100yds using 270gn Woodleigh's and 80gns ADI2209 or H4350, Fed mag primers, Lee crimp, the rifle has been bedded and trigger slicked up..Les

Hey Bigbrass: What magnification is your scope? My model 70 LH, when scoped with a 10X scope, gave me consistently overlapping holes at 100 yards. It may have been the most consistent gun I own. But after I put the "suggested" 1.5-5X x 20mm Leupold on there, well, now it shoots groups that look more like Rusty's. Not bad mind you, but not anything to brag about either.

But it's me that's the issue-- I suspect if I put that 10X scope back on there, it would be making one ragged hole again. I'm just not really good at precise shooting with lower powered scopes.

Just a thought.

Pertinax

This is a very interesting thread for me as I have just purchased a new .375 CZ American myself. I had already decided to glass bed but sent the stock back as I just could not stand it. I originally wanted the rifle as just a "working gun" nothing fancy. However, I am a notorious sucker for pretty walnut. When my rifle arrived it had a stock with all the character of a pine 2x4. I promptly called CZ about a wood upgrade and the stock is in the mail as we speak. The new stock will be glassed when it arrives. My question is whether it is best to glass the entire length of the barrel channel or just the forend recoil lug with the rest of the barrel floating? I'm leaning toward glassing the whole thing.

JBD, I had my Win. Safari Express 375H&H bedded out to the second recoil lug by a well known big bore gunsmith, he has done many of these and they all turn out much better shooters.

Pertinax, Yep I'm with you on this one, I mounted a Leupold V111 1.5X5 and though the groups were consistant like around the 2"/2.5" mark, I was never happy until I went up to the bigger Leupold V11 3X9 and now they all come in at the 1". Must be me eyes I reckon, ...Les