What causes horzontal stringing???

[Raptor]

I have a 260 I have been battling since it was new. It seems to string most of the groups horizontally across the target. I have been doing load testing at 300yds with it and even though I am shooting with wind most of the time I only get a cluster on a rare occasion.

Before we start on my shooting tech. I need to say that I am also doing load testing with a 6SLR at the same time and its shooting groups from 3/4 of an inch to 1.5"s with three different loads and two different powders all at 300yds.

The 260 only has about 1/2 to 1.5" vertical spread at 300yds but will go form 2"s to 4"s for horizontal. I have tried going up and down on loads and have seated from touching to nearly a .100 jump. I am really frustrated with this thing. The only time that it shot good was on a calm day and shot a 1"v by 1.5"H cluster. The rest of the time its patterns. I know at times it can be the wind but damn it the 123 @ 3000fps should hold as well or better than a 107MK at 3000fps.

I would be open to any suggestions. It has a Mcmillan stock, Kreiger barrel, Jewell trigger and is pillar bedded with plenty of barrel clearance. Thanks Guys!!!

 

[Lapua40X]

The things I find missing from your list is a description of your shooting platform.
Are you shooting from a bipod, adjustable rest, with or without butt bag, etc.
Front bag tension can affect both vertical and horizontal grouping. The rifle must slide freely and easily on the front rest to produce a uniform recoil.
Favoring one side of the channel on a butt bag that is designed with one (or if you make one using sand bags etc.) can put excess pressure on one side of the stock to produce horizontal stringing.
Inconsistent cheek weld can do the same thing.
Many of the problems associated with vertical stringing can also affect the horizontal.

 

[Raptor]

This is a tactical rifle and I shoot off the hood of my pick up on sand bags. Same with both the 260 and the SLR. The only difference is the SLR has a H&S VS stock and the 260 has a McMillan M40A1 stock. I tried shooting off a bipod but it was about the same, patterns not groups.

 

[skeetlee]

Could be a bunch of different things. Bedding, barrel, the bullet your using? Lots of options to look at. Is the rifle bedded? If not, start there. Good luck. Lee

 

[LHSmith]

Use wind flags and learn to read mirage.... then you won't be guessing if the conditions were the cause. Secondly, load tuning....some loads drift less in a right-to-left....or vice-versa.

 

[Raptor]

Rifle is pillar bedded. If its a wind problem then the 6SLR should be doing the same thing. Like I posted up above, I find it hard to believe that the 123 Lapua would drift more than the 107MKs at the same distance. Both rifles are shot within a minute or two of the other.

 

[Raythemanroe]

Same scope? See any Parallax? Triggers the same? You can input left or right on the trigger. Most will say seating depth and bedding I would guess, After your description I would recommend trying a bench and a nice rest to do any load work up.

 

[22BRGUY]

Same scope? See any Parallax? Triggers the same? You can input left or right on the trigger. Most will say seating depth and bedding I would guess, After your description I would recommend trying a bench and a nice rest to do any load work up.
[/quote

It sounds like either trigger pull or cheek weld or some kind of inconsistent pressure applied somewhere that isn't being done on the SLR. Is it possible for you to shoot this rifle and let it free recoil a little ways and only touch the very center of the trigger for 5 shots?

 

[stinnett1981]

Have a shooting buddy shoot the rifle too. If it shoots horizontal strings for him too then u know for sure it's something with the rifle. Even though you shoot your other rifle fine it's always good to make 100% sure by having a second person shoot it. Good luck guy!

 

[LHSmith]

Rifle is pillar bedded. If its a wind problem then the 6SLR should be doing the same thing. Like I posted up above, I find it hard to believe that the 123 Lapua would drift more than the 107MKs at the same distance. Both rifles are shot within a minute or two of the other.

It shot well in the calm....then your .260 load/barrel combination is not stabilizing the 123 's as well as your other gun's barrel/ load combination in conditions. You have to take note of what conditions you are shooting in. By not doing so, you're just wasting barrel life, components, and time. Bullets don't necessarily follow the drift charts. Again some barrels will seem to defy the wind , left, right or both, while others will have more difficulty grouping in wind no matter what attempts are made to tune. In short range BR, the best aggs are shot with some condition.

 

[Raptor]

Tried two different scopes and put the Jewell in it awhile back. I will wait for a quiet day but its really hard to find here in S. Dak. Thanks guys I really appreciate all the tips!

 

[North Fork]

I hate to say it but you just mite have a bad barrel

 

[dickn52]

Ok, I'm new and admit it. BUT are the spreads both left and right of aim point? I mean if they are my mind thinks pilot error or something else I have no knowledge of as apposed to a bad barrel, which would throw consistently left or right. Feel free to pile on if I am standing in a field with a iron pipe in a thunder storm all by myself.

 

[22BRGUY]

Would also wonder if a scope level would help to keep the stock in the same vertical/horizontal position from shot to shot.

 

[jonbearman]

Does the gun jump when fired in your bags? Are you using stock tape so the stock doesnt grip the bags?

 

[Raptor]

The barrel isn't bad. The gun will shoot. I had a load that shot very well but it would ruin the brass in about two firings. I have had some guys PM me saying I need to play with the seating depth more. This may be the case since it went from patterns to more of a horzontal line.

I started off by seating out to the lands and now have been sinking the bullet deeper but I may have taken to big of a swing at it and need to fine tune it more. Once again thanks for all the replys!!

 

[artbosco]

You may be shooting into a letup or a push. Get some windflags and find out.

 

[xpilot]

I would try more jump. My 260 shot the 123 best with .020-025 jump.

 

[artbosco]

Pulled this from my Benchrest reference file. See if it helps:

TUNING OUT HORIZONTAL & VERTICAL DISPERSION

Most of my shooting during the past several years has been in the wind free environment of the tunnel. One thing that continues to repeat with every gun, barrel and bullet combination I have worked with is that

horizontal dispersion results from bullets being seated too far into the lands

vertical dispersion is the result of the powder charge being either too hot or too light.

Daryl Loker told me years ago that you tune out horizontal with neck tension and bullet seating depth,

tune the vertical out with the load. (Or in recent years since the advent of tuners, with the tuner.)

I assure you, if I put my standard load of powder in and seat the bullets on hard jam, I'll have two bullet holes of built in horizontal, and that's in a tunnel with no wind!

Pushing bullets back into the case .005 at a time, and the horizontal will disappear just when the bullets come off the lands or just kissing.

You might as well keep this to yourself after you see it with your own eyes because no one will believe you if you try to tell them; it goes completely against conventional wisdom.

Gene Beggs