Looking for help with 375H&H accuracy problem.


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BBW
March 8, 2009, 12:16 AM
I've got a 375 H&H that I'm looking for some help with. It's a Remington 700 XCR. I'm a thumbhole stock guy, so I put on a Boyds thumbhole laminate. I've glass bedded the action tightly and tuned the trigger down to about 3.25 lbs.

So far I've been completely unable to get this rifle to shoot. It's giving my 3-5" groups at 100 yards regardless of the loads I feed it. I was careful to break in the barrel correctly when it was new. And I tried fully bedding the barrel and then removing the bedding to free float it. That doesn't seem to have made any difference.

I did find something out this evening that kind of irked me. I broke out my Sinclair tool for calculating overall cartridge length. With a Sierra 300gr bullet I would have to seat it out to 3.785" to get the bullet touching the lands. (Standard max OAL for the 375 is 3.6".) Now, I understand that rifle manufacturers want to give us a little freebore to save us from ourselves. But .185"??? It would be nice if the bullet and the lands started in the same frickin' county for Christ's sake! That's coming up on 1/5 of an inch of freebore.

Naturally I can't seat my bullets anywhere near the lands and still have them fit in the magazine. I can't imagine that such a big jump is helping my accuracy any. And I'm really looking to find out what the culprit is. I would expect an off the shelf 700 with a tightly bedded action to shoot more in the 1-1.5" range at 100 yards.

What do you think, is it worth taking this rifle to my gunsmith and having him turn the barrel in to get my freebore down? Do you agree that so much freebore is likely a problem? I think I've done all I can with the bedding. I'll probably put a Shilen trigger on it, mostly because I don't like the feel of the stock one. But I wouldn't think that would make that much difference.

By the way, does anyone know what the standard freebore was on a 375 H&H back before guns were designed by lawyers? It's not a high-pressure round like the Weatherby's, so I wouldn't think it would need that much.

Thanks,

Ben

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win71
March 8, 2009, 12:38 AM
I doubt I can help much on the free bore question. It doesn't seem to effect Weatherbys accuracy that much. The only two 375 h&h I have are a Ruger single shot and a Colt Sauer. The Colt shoots around an inch at 100 yds.
Just for drill try a 300 gr. round nose bullet in your reloads. It should hit the rifling way sooner than that pointy Sierra.
I know all the stories about loading out to the lands for greater accuracy but that is not a steadfast rule. For instance I have a Douglass barreled Sako 222 that shows it's best accuracy with deep seated bullets.

BBW
March 8, 2009, 12:57 AM
Thanks Win71,

I may try the round noses. I had another 375 a few years back that liked those. My only problem with them is their lousy long-range performance.

I may try seating a few rounds out towards the lands (wherever they may be). I would have to single load them, but at least it might give me intel on whether that's the problem.

Ben

Strongbad
March 8, 2009, 10:31 AM
How many loads have you tried? How many different bullets/powders? Just out of curiosity? What about factory loads? I know that a box of 375 factory ammo wont be cheap but atleast it'll give you a baseline. FWIW I don't believe that freebore is your issue.

win71
March 8, 2009, 11:24 AM
It might be a way to confirm the free bore theory at least. Not that it could be your problem but this was mine. I don't think most shooters can hold a 375 the same as a lesser caliber varmint or bench rifle. Since it requires a tighter hold to control in recoil it's more difficult to keep it consistent. I really have to concentrate to get a decent group.

Onmilo
March 8, 2009, 12:01 PM
Do you have a crossbolt in the stock that bears against the receiver between the magazine box and the front screw lug?

The receiver may be the trouble and not the barrel.
The receiver may be twisting in the stock during recoil.

You could try pillar bedding the receiver screws and installing a stengthening crossbolt to stabalize the receiver.

You may also find that .375 Magnum barrels gain best performance when barrel is free floating all the way to the forend where a pressure bedding pad bears just at the forend tip.

BBW
March 8, 2009, 12:10 PM
Hi Strongbad,

I've tried a bunch of different bullets. I've tried the Sierra 300s and 250s, the Hornady 300s and 270s (both spire points), and the Speer 235s. For powders I've mostly been sticking with the recommendations from the loading manuals (r15, IMR4064, Win760, VN550, and H4895). None of these combinations has shot better than any of the others.

Win71 -I hear you on how much harder it is to shoot 375s than other rifles like my 308s. But I don't think that's it (or at least not all of it). If nothing else I would expect that the 235gr Speer would have shot well. That load tends to be accurate and the recoil is pretty low. But I've shot other 375s that I didn't have the same problem with. I used to have a Winchester 70 Safari Express that would shoot between 1/2" and 2" depending on the load. And that was a gun that didn't fit me as well as this one does.
Though to test that theory I'm planning on going to the range with a buddy of mine who shoots a 416 Remington. He's a pretty good shot so I'll have him try it just to confirm that his groups aren't better than mine.

Onmilo -No, there's no crossbolt. But this is a laminated stock. Should it need one? I thought those were mostly there to prevent splitting in wooden stocks.

Thanks,

Ben

Runningman
March 8, 2009, 01:38 PM
Did you shoot the gun with the factory stock and factory ammo before changing the stock? If so what did it do?

Do you agree that so much freebore is likely a problem?Simple answer is no.

My Sako 375 H&H has just about as much bullet to land clearance and it rarely shoot groups bigger than 1.5" @ 100 yards. With better loads groups will approach close to 1". I also have a Remington 700 in 300 WBY that has much more bullet to land clearance than you are taking about that will shoot some loads under an inch. So I don't think your free bore is responsible for 3-5" groups.

The best shooting bullet for me in two 375 H&H has been the 300 Nosler Partition with the 260 grain Nosler close behind have you tried any of these bullets? After these two the 300 Grain Hornady round nose has also been an accurate bullet for me.

I never had much luck with the 300 grain Sierras in two 375s. But they did not shoot groups that large.

Gaiudo
March 8, 2009, 01:58 PM
I've been getting good groups with the Barnes TSX 270 grains, using RL15 several grains under max loads. I'd try the Barnes before the round noses, personally, as I wouldn't see shooting too many of the RN anyways.

How much are you crimping? Overcrimping really threw my loads into the stratosphere, and when I backed off a bit my groups tightened right up.

BBW
March 8, 2009, 02:13 PM
Thanks guys,

Runningman -No, unfortunately I didn't shoot it with the factory stock. I new I was going to want the thumbhole, so I just switched it over. That way I could sell the original stock as a brand new take-off. But now I wish I had kept it. I'd be curious.

I haven't tried the Noslers yet. I wanted to work with the cheaper bullets first before going up to the premium ones.

Gaiudo -I did actually try the 270gr Barnes TSX (forgot to mention that above). That's one of my favorite bullets, so it's usually the first one I try and get to shoot well. But then I backed off. They're kind of expensive to shoot a lot of if the rifle is giving you problems in general. I tried both R15 and H4895 with those.

I'm not crimping at all with these. I tend not to. But everything I'm shooting at this point is single loaded, so I know the OAL isn't shifting from recoil.

I think I'll try the round noses this week. I want this to be a general hunting rifle, so ultimately I'll need it to be able to shoot spire points. But it would be interesting to see how they shoot.

Ben

Gaiudo
March 8, 2009, 02:17 PM
By the way, I'm shooting mine just off the lands, at 3.575 OAL. So yeah, there's a major difference there in the freebore of your rifle.

BBW
March 8, 2009, 02:40 PM
What bullet are you shooting to get that close to the lands?

I checked the OAL with the roundnose bullet and at the same OAL as the Sierra it would be almost .1" closer.

Ben

jstevens
March 10, 2009, 05:02 PM
Most .375's I've owned have the OAL decided by the length of the magazine. It certainly never hurt accuracy, I have never had an inaccurate .375. I have always had the best luck with RL15 and 4064, never saw one that wouldn't go close to an inch with a good bullet. I would be less than surprised if you have a scope/mount problem.

Robert
March 10, 2009, 06:03 PM
I am curious is your scope, I assume you are using one, mounted properly? I have seen some terrible groups that were cause by a bad scope. If not the scope then I would suspect the stock as it was the only thing you really changed. You might have a gun smith take a look and ensure the rifle was assembled to spec.

BBW
March 10, 2009, 08:55 PM
Yeah, thanks guys.

I had some thoughts about the scope too. It is a used one. But it's a Leupold VX-III, and I've generally found those to be pretty rugged. It's sitting on a one-piece solid base with a set of Warne rings.

I may have had a little luck today at the range. I tried two new loads. One was shooting the 300-grain Hornady round nose bullet pushed by Win760. The other was the Speer 270-grain BTSP. Those two shot better, about 1.5" on average. But in both cases I seated the bullet out pretty far. In fact, the Speers I had to single load. They wouldn't fit in the magazine. I may try seating them back to functional length and see if they still shoot that well. I'd like to get under an inch with this thing. But those two loads show promise at least.

I'm going to take it to the gunsmith tomorrow to have him look at it. I may just bite the bullet and have him put a Broughton barrel on the thing. I don't want to sink a ton of money into it, but I want it to really be a shooter.

I have a similarly set up 308 that's got a heavy Bartlein barrel on it. With the right loads that rifle will shoot about 3/8 of an inch. I'd like this 375 to be it's big brother. I figure with an accurate 308 and an accurate 375 I'll be set up to hunt the world. (Bummer Bartlein doesn't make 375 barrels, but I hear Broughton are good too.)

Ben

ShadyScott999
March 10, 2009, 09:22 PM
I would take the scope off and put it on another rifle. If the scope shows good, I would glass bed the action (tang). If that doesn't work, I would assume that it is the freebore. I really think that(freebore) is what it is. The first two suggestions eliminate variables on the cheap.

nksmfamjp
March 10, 2009, 10:01 PM
Just a quick point, you could load bullets to the lands for testing, but I don't think you will find it is fixing your issue.

With a heavy recoiling gun like that, I would first check my most experienced buddy's groups to mine with a box or 2 of factory fodder.

Then, I would check the bedding. Is your gun holding torque on the action screws, or do they shoot loose? Normally without pillars, wood stocked guns are kind of a never ending chase to keep them torqued. I only go back to the bedding because of the caliber's power level. What works in 6mm pipsqueak might not work with the 375! Last, try shimming the forearm right at the point where the forearm ends. This point bedding has been said to be effective at controlling groups with factory tubes. It usually requires a slight interference to work right.

Gaiudo
March 10, 2009, 11:08 PM
What bullet are you shooting to get that close to the lands?

I'm shooting the Barnes TSX 270 grain. Here's the grouping I've been getting with it: http://www.thehighroad.org/showpost.php?p=5400396&postcount=24

I was also using a VX-III, though an older model. Have the newer models been holding up well?

BBW
March 15, 2009, 11:13 AM
Well, I may have wussed out here.

I was at the gunsmith's last week letting him take a look at it. I finally decided f**k it, and told him to blueprint the action, lap the lugs, pillar bed it and put on a 23" Broughton barrel with a #5 contour. That should make for around an 11lb rifle, but it should shoot great.

I'm a guy who really only has two hunting rifles; my 308 and this 375. So I decided I wanted to invest some money into it and just make it a great shooter. I don't want it to be picky about ammo and I want to have great confidence in it (just like my custom 308). A rifle that only likes ammo X won't help me if I'm in Alaska and can only find ammo Y.

Oh, and I'm having him bolt the bolt handle down. Had enough of that damn thing popping off in my hand.

Ben

Runningman
March 15, 2009, 12:06 PM
Sounds like a good plan to me. I know what you mean about not wanting a rifle that is finicky about ammo feed it. I've have several Remington 700 that were this way over the years. Got tired of it myself. Had aftermarket barrels put on them and it was like shooting a different rifle. Confidence in your rifle can only help.

BBW
March 15, 2009, 02:08 PM
Yeah, I think I'll be happy with it. I like the fact that while my 308 has it's favorites it will shoot well with everything I've tried. That's both convenient and confidence inspiring.

Besides, the amount of money you save in cleaning patches with a custom barrel ends up paying the difference after the first few thousand shots.

Ben

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