Home Forums Hunting & Shooting Ask The Gunwriters Rifle Accuracy problem

I have a a 375 that I have setup for general purpose hunting, from short range to long. But I am struggling with getting the accuracy I am hoping for, so was hoping for some advice on where to go next.

It is a win Alaskan. It actually shoots Federal 300 gr Powershock RN's into about .5 to 1" groups (3 shots) fairly regularly, which would make me happy enough.

However, I am trying to get something that shoots flatter and is lighter. So I have handloaded some 260 accubonds, as well as some 250 TTSX's...and some Sierra 250's as well. The accubonds will often put two bullets into 1 hole, seriously one hole, but will always throw one of the group out, opening the group to 1.25 to 1.5 or even worse. Today, I had a better shooter on the gun and he shot a 6 shot group to see what would happen, and it went back and forth, alternating between two clusters, with 3 touching, two more touching in a different group, and another kind of off on it's own. Overall, it was a dismal 1.8".

All of these are being loaded with fired federal cases, sized to my chamber. Win Mag primers and RL15.

The TTSX's, well, I don't know how to describe the results there, just terrible, the Sierras I have not shot much of yet...got 1.3" 3 shot group out of the one group I shot today.

It occurs to me it could be my handloads...velocities over the chrono seem fairly consistent, (though heating clearly makes the velocities climb!)but maybe I have a lot of runout or something?

The other possibility could be that my rifle wants those big roundnoses...or maybe 300's in general.

Could this be a bedding issue? Just not sure.

Any suggestions on how to diagnose this? My goal is to get a 250 to 260 shooting fairly flat and at least MOA for 3 shots. But so far, it's not working out.

Thanks!

Where are the two different groups relative to each other?

Could be a bedding issue. If it has the factory "hot glue" type bedding, I'd re-do it for sure...If it is a newer FN, you are less likely to have a bedding issue but it still happens with them. Trust me, I have had to re-do the bedding on a few new FN's. Personally, I wouldn't waste ammo in a rifle that was not bedded to my satisfaction. I'd also check for pressure on the barrel from the stock. A good 375 is generally not finicky. Good luck with it..

Besides bedding, COAL may be a factor.

For diagnostic purposes; make some cartridges, with the bullets that you are finding problematic, with a COAL where bullets kiss the lands. The COAL may be too long to feed from the magazine so you will have to single load them. If groups improve, that will tell you COAL is a factor.

Like your rifle, my Sako .375HH shoots RN bullets exceedingly well. Spitzers and semi-spitzers not so much unless I load them longer than the magazine will allow.

However, unlike your rifle, my Sako will shoot TSX bullets seated to feed through the magazine MOA-ish which is consistent with the finding that TSX bullets are generally not as fussy with a longer bullet jump.

While there are several potential causes for 2-grouping, my first suspect in any accuracy problems is the scope, especially with a harder recoiling rifle. ince even the best-shooting load (the Federal Powershoks) is only grouping "fairly regularly" I would still consider the scope a possibility.

It's almost impossible to diagnose accuracy problems over the Internet, because the list of possibilities is so long. Somebody is almost always going to immediately suggest rebedding, but in my experience it's more productive to try simple stuff first:

1) Another, proven scope.
2) Testing the loaded rounds for bullet straightness. Often factory loads have bullets seated straighter, because the brass hasn't been resized yet, so they group better.
3) Varying seating depth.

Also, since you admitted to having "a better shooter" test the rifle, it simply might be a case of you not shooting a .375 very well. This isn't uncommon. You statement about the Federal loads shooting small groups "fairly regularly" might also be an indicator.

Nothing useful to add, just curious.

When you say alternating does that mean shooting into one group then into another group then back to the first? Alternatively is it two shots first from a cold bore than a warm bore shooting together then the third and subsequent shots move around more and perhaps more again?

FWIW My own choice has been the 260 Accubond for anything I plan to shoot with the bore. Low power light weight fixed scope too.

IIRC, the first bullet always goes in the same place, the next, often right in the same hole, the third, however is usually higher,left or right, but not always. The 4th usually comes back to the original group. The 5th back out to the second group.

This one is an FN. Hope it's something simple like bedding, or, better yet, my bad reloads!

[/quote]

Besides bedding, COAL may be a factor.

For diagnostic purposes; make some cartridges, with the bullets that you are finding problematic, with a COAL where bullets kiss the lands. The COAL may be too long to feed from the magazine so you will have to single load them. If groups improve, that will tell you COAL is a factor.

Like your rifle, my Sako .375HH shoots RN bullets exceedingly well. Spitzers and semi-spitzers not so much unless I load them longer than the magazine will allow.

However, unlike your rifle, my Sako will shoot TSX bullets seated to feed through the magazine MOA-ish which is consistent with the finding that TSX bullets are generally not as fussy with a longer bullet jump. [/quote]

Yeah, I am afraid it is the same issue. I have the TTSX's loaded out as long as I possibly can, just barely crimping into the cannalure. Might try and load them to the recommended length and see if that changes anything.

The worst frustration is with the accubonds, over and over, 2 shots in 1 hole, the next in neverland. I actually have seen the same with Sierras as well, so I thought it was me and got a better shooter, but he got the same. Can't even get close to the lands due to box limitations, so I think I'll try those longer than box length to see what happens as you suggest.

Maybe another step is to find some 300 RN's and 300 Accubonds and try those. Definitely not what I had in mind, though.

Another possibility is maybe finding a skilled (as opposed to me) handloader, in case that is where the problem is.

John,

Thanks for chiming in! I probably wasn't very clear on the powershock grouping, with me shooting, it's pretty consistent 1 to 1.2 inch groups. With my friend, he hit one at .53 and another around .7. These groups are almost always nice triangles. But I'll see if I can find another scope to swap. I was wondering about the scope as well.

Run out was something I was wondering about too...is a concentricity gauge the only way to test this? And would one test a newly sized case as well as a fully reloaded round?

On seating depth, I can go deeper, but not longer unless I single feed them, so I'll try both and see what happens.

On me being the problem, definitely a possibility. I got another guy to shoot because of that, but while a competitive shooter, he has no experience with bigger rifles without breaks. That being said, he did hammer out a couple nice groups with the 300's right off (.53 and about .7). But his groups with the accubonds and TTSX's looked like mine.

He thought it might be heat related as the barrel gets hot really fast, and it was 96 degrees outside when we went to shoot. But I continued shooting after he left and had similar results as I have had when it was fairly cool.

Either way, I'll try all the stuff everyone has recommended..that is, different scope, longer length, 300 grainers (spitzers and RN's), shorter length, try and find concentricity equipment...

Thought about trying to get some 260 accubond factory stuff, but at 80 a box....wow...that's an expensive test. But that might be what I need to do. That and a lead sled to take human error out of the equation as much as possible....both I have been trying to avoid.

Clark,

In the 6 shot group I mentioned, the first two went into one hole. The next one was high and to the right, the next, I think, was back touching the first two, the fifth went high and to the left and the 6th was high and to the right touching the other two. IIRC!

I was not shooting at the time, my friend was.

Maybe I miss read the post, but the largest group he reported was less than two inches at one hundred yards. I would think that this would be sufficient for any thing you would need a 375 for.

Well, it depends. His first sentence is: "I have a a 375 that I have setup for general purpose hunting, from short range to long."

So it depends on what's meant by long range, and the .375 is often used on game smaller than it's "needed for," since it's so versatile. I would agree that 2" groups are plenty good for 400-yard shooting on animals the size of big deer on up, but dunno what he means by long range.

Part of the problem may be today's notion that "half inch groups all day long" are necessary for shooting big game even at pretty long range.

catorres,

Let's start again by defining what you mean by "long range."

For a lot of shooting, even at pretty long range, you don't need a concentricity gauge. Instead you can just roll loaded rounds across something very flat, like a mirror. If you can see the point of a spitzer wobble, the bullet has more than .005" runout. If it doesn't wobble, then they are plenty straight enough to result in good accuracy. If they don't, the problem lies elsewhere.

For a quick answer on this, I am hoping for 1 moa for 3 shots out to 500. That is my goal. I know 5 shots is significantly more accurate, but I think this will meet my needs. I'll be shooting everything from elk down to small pigs, javelina, black buck...even maybe jacks and coyotes...then for play...steel to 1k. The purpose is one gun to do it all, compromises included And part of the goal is having it arranged so no matter what the future brings or offers, I am equipped and capable (two very different things!) to do it with this one rifle.

I mention it as a goal because I am not good enough to do this anymore, but I am working to get back there and I want the equipment I settle on to be capable as well.

Anyway, I think I have located a fixed 6 power Leupold to swap out for my Zeiss to see if it's the scope. So that's the next step.

But also I laid out all the targets I have and just tried to see a pattern. There was nothing consistent (made difficult in that many were shot with different loads), but while I have checked all screws several times with a torque wrench (no problems found), I decided to run a business card down the 'free floated' barrel channel. It went in easy for the first 3/4 of an inch, but then got quite tight. It would go, but it was definitely much tighter then at first, and noticably tighter on the right than on the left. After another 2 inches or so, it loosened up again.

This might be significant in that if you squeeze the forearm, it's flexes easily and you can contact the barrel easily, especially towards the tip.

I wonder if it's not properly free-floated and it is contacting the barrel and causing these problems, especially as the barrel heats up. In laying out all my targets, I did note that the best groups were shot off of a cold barrel (which is when I usually shoot the factory 300's...using them as foulers), or after I noted a longer cooling break, with the worst groups being as the rifle heated up. This is not 100% accurate, but it's a suspicion I have to the best of my memory as to order of groups etc.

But first, the scope. That's free and easy. We were shooting 1/2 groups yesterday with a 6 power on an AR, so I think it will be sufficient to answer the scope question.

But assuming the scope checks out...does this sound like a floating problem? I always assumed a properly floated barrel would easily allow a business card to slide through with consistent ease, but maybe that's not the case. I don't have anyone locally that I trust to have look at it and answer for me, if I want to get it worked on, it's going to have to be shipped somewhere, so before I do that, I should probably know what a 'problem' looks like.

Thanks!

Yeah, it sounds like a barrel-floating problem.

Apparently you've never read my book RIFLE TROUBLE-SHOOTING AND HANDLOADING. It goes into detail about free-floating barrels, and how much "float" is required for accuracy. If you can squeeze the forend and barrel together easily, the barrel ain't floated enough.

John suggested a free float method to me that has several loads shooting 3/4" or less regularly, and frankly I'm now disappointed if the 3 shots are not touching and I'm well below 1/2".

Long over due thank you John. Thank you.

You're welcome!

And thank you for the generous words.

Awesome, thanks for that! I have some pieces of glass around here so I ran one across it and I could detect no wobble looking straight at the tip. Tomorrow, I will pull out all the loaded ammo I have left and check them all.

I missed this reply before typing the other, but basically to answer your question, the *goal* is to have 1) the skill 2) the equipment to match the skill to shoot at any game out to 500. My local range has steel out to 1k, so I'll want to do that as well for fun and practice. I am not there yet, but am working on the skill part, but want to know that my equipment is also more than up to the task. I am looking for some training, and all I have seen available to me require 1 MOA or better for their classes, so I need to get there one way or another.

Thanks!

Ha, looks like a I am about 2 posts behind on replying! Thanks so much for all the help!


I just tried the rifle again with a folded dollar bill, hard to get it through that point, but then easy all the way to the chamber...then almost could not get the dollar back past that point, it was very difficult and I almost ripped it getting it through...

So is this method you mentioned involved or simple? Or is this a case where you would just recommend going and having it properly bedded? I am not handy so I will not take on a bedding job myself, so I'd need to ship to a smith to get this sorted if that is the case.

As for the book, definitely have not read that one, did not know about it, looks like that needs to be on my buy list as I suspect it probably will help me be a better loader etc?

Have read "Life of the Hunt", in some ways, a game changing book for me in how it expressed for me what I could not figure out how to express, even to myself. I lost my copy when I moved to Germany, but I need another for my son who is now 11. He will love it...he is writing his own hunting stories (fiction in his case)...pretty cool, except the first one has me dying in a few years and leaving him enough money to move to Alaska. Thanks alot, son!

Anyway, I'll need to find a copy of those two books, thanks for all the advice, helpful as always!