Questions on benchrest shooting .375H&H

[phil mcwilliam]

I went to the range yesterday to sight in & try various factory ammunition in my newly acquired CZ550 Safari Classic chambered in .375H&H Magnum & topped with a Leupold 2-7x33 scope.
After getting on paper at 50 yards, I started shooting 3 shot groups at 100 yards, between adjustments. I was happy in that the 3 shot groups using 300 grain Federal ammunition were all around 1 1/2 inches, with one group coming in at 3/4 inch.
After firing 20 of the federal 300 grain rounds, I swapped to Hornady 270 grain rounds. After firing another 20 rounds of the Hornady, I found my groups had opened up, with the last 2 shots not even being on target.
I was actually complemented on the way my rifle grouped by the guys either side of me at the range, who had witnessed my earlier groups through their spotting scopes, but I didn't let on that my last couple of shots had not even hit paper.
I decided to call it a day after 40 shots & went home to contemplate things. At home checked scope to see if it was tight, which it is. I then got to thinking that maybe my accuracy was falling off after firing 40 shots of .375 H&H magnum in around an hour.
I know my questions will be answered on my next sighting in trip- purchased another 4 boxes of federal 270 grain rounds to try next time, but how many rounds do you benchresters shoot in one sitting, when shooting a .375 H&H Magnum?

 

[Creeper]

There should be only a modest point of impact change between 300 and 270 grain cartridges at 100 yds.

The number of rounds isn't really relevant (at least not to the gun)... a dramatic change in point of impact however, is.

Is this a new gun? Are you breaking in the barrel, and cleaning between X shots... or did you just shoot 40 rounds with no cleaning at all?
To be honest, even that wouldn't cause a grouping gun to open up completely off paper... so I'm leaning towards a mechanical issue.

The scope may be tight, but it may be coming apart inside. New scope? Is your objective adjustment loose? Brand and type of rings? Is the scope slipping in otherwise what appear to be tight rings? If you have iron sights, remove the scope and try using those.

Action tight in the stock?

Is this a floating barrel, or does it have a pressure point?

Barrel tight? When you chamber a round, is the bolt closing with no resistance what-so-ever, or did that seem to change as you shot?

Did you change the type of rest you were using?

What does a fired case look like compared to an unfired case? Do you have some dial calipers to take a few measurements of case OAL and diameter at various points?

Or... after 40 rds of 375 H&H, were you just flinching like crazy?

That's all I got off the top of my head, I'm sure others will have comments/questions.

Cheers,
C

 

[mrawesome22]

40 in one hour you probably could have fried an egg on your barrel?

Hope you didn't roach it.

Could have just been your flinch getting worse and worse.

Sent from HenseMod6.

 

[10-96]

Just one wonderment that hasn't been wondered upon yet- Does the stock have a crossbolt? If not, have you removed the bbl and receiver from the stock and put it under real bright light?

 

[mete]

On another forum there was a detailed discussion of cartridges of 375 H&H and higher recoil .The agreement was that thos erifles shoud have two crossbolts and be glass bedded !! Otherwise stock breakage , loss of accuracy etc !!

 

[Scorch]

Having owned and shot a 375 H&H from the bench, I would say that you were flinching or anticipating the shots. Shooting from a bench, you will take a lot of punishment since you cannot "roll" with the recoil. I would work on offhand shooting and get really good with the rifle, sounds like a good shooter.

 

[kraigwy]

I never had much luck bench rest shooting my Model 70 in 375 H&H. When I stand on my hind legs, it prints a bit different. So I do my zeroing standing or setting. I doubt I'd run across a bench while hunting anyway.

As mentioned the 375 has a habit of putting pretty much all bullet weights in the same neighborhood, at least in my rifle.

 

[phil mcwilliam]

Thanks for your replies and suggestions. I have now checked over the rifle and scope to the best of my ability & have also done some more contemplating & relooked at the targets which I had saved.
In replaying the days events over in my mind I shamefully admit I may have the answer to my problem and it may not be as sinister as some of the suggestions. The original 20 shots of 300 grain federals grouped & tracked extremely well, with one 3 shot group coming in at 3/4 inch.
I was surprised that when changing to the 270 grain Hornady rounds that they shot about 7 inches high & about 1 inch to the right, as I had read that the .375 H&H Magnums usually shoot different bullet weights similarly. In rechecking the targets the 270 grain rounds were still grouping, although 5 shot groups had increased to average 2 1/2 inches.
The 270 grain bullets were also tracking properly through the scope as I can see where I have adjusted for height & got them shooting about 2 inches high at 100 yards, but still about an inch to the right.
For my last five shots I adjusted the scope for windage, and because of the previous bullet holes in the target, I picked a spot on the right side of my target to aim. This is when I had two misses.
With my head held low in shame, I think after some 40 years of shooting, that I may have adjusted the windage in the wrong direction, which caused me to miss paper.
I will be travelling to my farm early next week & will continue my sighting process then. The bruises on my arm need a couple of days to settle down anyway.

 

[Kreyzhorse]

I hope you simply made the wrong adjustments. While .375 isn't terrible to shoot, 40 rounds really starts to add up and it will certainly effect your aim over time.

If the gun really tore you up, try to limit some of your shots with to make sure it's the gun and not your beat shoulder.

 

[myshoulderissore]

Agreed, let some time pass between groups, and if you even MIGHT be flinching, shoot a .22 between .375 groups.

 

[darkgael]

Wow

40 shots in an hour from the bench. Wow.
Were you in a hurry?
Two boxes of .375s is enough for a whole morning.
+1 about getting the rifle off the bench. I shoot my M70 seated on the ground or standing. Either one keeps me from getting beat up by that big ol' cannon.
Pete

PS - price of ammo being what it is, I hope that you are saving your brass for reloading.
P

 

[kraigwy]

PS - price of ammo being what it is, I hope that you are saving your brass for reloading.

I got the answer to that. Yes I do reload, but for bullets, I have a mold that used 3/8 copper tubbing, cut to lenght, I place the tubing in the mold and pour the lead. The end product is 270 grains. I do run it through a sizer to make sure they are perfecty round. Cheap jacketed bullets, fairly accurate. Makes some excellent practice ammo making my 375 H&H one of cheapest rifles to shoot I have.

 

[zippy13]

Kraig, great solution. It's always sweet when you can shoot a big gun inexpensively. I'm curious, how do you get your lengths of tubing uniform, a case trimmer, or... ?

 

[Clifford L. Hughes]

phil mcwilliam:
When I took my new M-70 Winchester .375 H&H t0o shoot for the first time I took twenty rounds with me. Being excited, I shot the .375 first. I was wearing only a tee shirt and I was shooting low on the bench. During the last five rounds I noticed that I was flinching. When I finished I fellt pretty good and went to the car for lunch. Aftrer lunch I took my 30-30 to the bench. When I fired the frist round a pain shot through my shoulder. My shooting was over for the day.

The way that I solved the problem was to wear a strap on shooting pad and wear a 10X shooting coat. Instead pf shooting low on the bench I raised my rest high enougn that I simulated off hand. That way I could roll with the punches. I can now shoot twenty to fourty rounds of .375 without flinching or punishing my shoulder. However, the .375 is no tabby cat.


Semper Fi.

Gunnery Sergeant
Clifford L. Hughes
USMC Retired

 

[aarondhgraham]

How many rounds?,,,

...but how many rounds do you benchresters shoot in one sitting, when shooting a .375 H&H Magnum?

Just one,,,
That was all I wanted.

I'm tall and slender (pot belly),,,
I've fired many rifles that start with the number 4,,,
The .375 H&H Magnum is the one rifle I don't ever need to shoot again.

Aarond

.

 

[FrankenMauser]

Firing 20 rounds of .375 H&H takes its toll on the body, especially when fired from a sitting position. A standing bench is much better for your body.

Even if you aren't aware of it, your body shows signs of stress and fatigue after as little as 3-5 shots from many of the large 'magnums'. The noise level (even with hearing protection), the concussion, and recoil all have physiological effects.

It is not surprising that you saw your group size increase or a massive POI shift, after throwing 20+ rounds down range in a short amount of time, from a sitting position. (I'm sure barrel heat was a player, too.) Continuing to fire the other 20 rounds just made things worse.

Next time you take the rifle out, take it slow and pay attention to what your body is telling you. You'll probably notice some complaints that are easily brushed off, if you aren't paying attention.

 

[BusGunner007]

I commend anyone who shoots a .375 H&H.
I bow to the one who shoots that many rounds in one session.
I grovel at the feet of the Beast that shoots 40 rounds in 1 hour...

Seriously.
Last time I took out my Remington 700 / .375 ULTRA MAG, I shot 3 rounds after breakfast and worked my way DOWN in caliber 'til I got to my .22's!!!
Don't think I'll ever pop off 40 rounds of .375 RUM in an hour. Ever...!

You have my respect, Sir!

 

[warbirdlover]

Only experience I've got shooting a .375 H&H from the bench is a fellow shooter let me try his Ruger #1 at the range. It didn't kick any worse then my Ruger 77 .300 Win Mag. But I would NEVER shoot 40 rounds through that at the bench. About a box is plenty for one day. Ouch.

 

[Art Eatman]

Any time I plan on an extended session at the bench rest, I interpose a small sandbag between the buttpad and my shoulder. That effectively makes the rifle heavier insofar as the force of recoil, and spreads the impact over a wider portion of my shoulder.

Masochism = High vacuum.

 

[phil mcwilliam]

Just got back from a week at my farm where I was able to continue to sight in my .375H&H CZ, this time with Federal .270 grain ammunition. On the way to my property I stopped at a hardware store & purchased 3 garden stakes & a roll of adhesive tape- to make some shooting sticks.
In between moving cattle, straining wire fences & track maintenance , I was able to tryout the .375 again. This time I took my time in shooting, & had purposely limited my shooting in only taking 1 box of ammunition with me. I still had to make adjustments, but was able to shoot 2, 3 shot groups at 100 yards that were around 1 1/2 inches off the shooting sticks, which was good enough for me.
I put my bad grouping a couple of weeks ago at the range down to a few things. The federal ammunition grouped way better than Hornady ammunition through my rifle - good ,as the federal was half the cost. I also believe I had mistakenly adjusted the windage, putting me off target at the range.
One thing I did learn was that this particular rifle shoots & groups different brands & weights of factory ammunition way differently, even at 100 yards.
I found using shooting sticks, or standing using a fence post or tree as a rest better to shoot the .375, than benchrest shooting. The cold weather probably also helped with me wearing multiple layers of clothing.
I also found the .375 actually teaches you to hold your rifle correctly, cause it bites you if you don't
I guess the only mistake I made this time was limiting myself to a box of 20. Once the sighting in was done, and a tree branch lopped from the top of the chicken shed, it left me with limited rounds for hunting, but 4 feral goats with 3 shots was rather satisfying at around 200 yards.