Shots stringing on target? In working with some loads today I had groups string both vertically and horizontally (different loads.) There must be a reason for this non-random groups--
FYI
W70 featherweight 3006AI
RL19 (vertical 4" groups)
IMR 4350 (4" horizontal groups at lower loads, grouping better as I approached max)
Can you learn something from the shape of your on-target groups?
Thanks!!!

Sure does mean something...

Either the rifle can't shoot;
You can't shoot;
or the loads are not right for the rifle...

The "BOING~" in your "whippyweight" barrel.

I have a Swedish mauser that can shoot one of my loads into a cross shaped 10
shot group. Despite the cross string it is as small as 3/4" at 100 meters.

[ 06-05-2002, 16:35: Message edited by: Pyrotek ]

You might have a bedding problem.

It has been my experience that vertical stringing indicates a bedding problem and horizontal usually means the charge aint quite right meaning MORE POWDER.

i had a 6.5x55 load that was stringing horizontally. a benchrest type guy at the range told me that meant the load was a little too hot. i backed off a little and now it shoots little clusters into an inch or less if i'm doing my part right. this is the one and only experience i've had like this. don't know if the load was too hot or if my gun just likes a little less powder for some other reason but when you find a load that works you don't argue, right? cheers...bud

I think that stringing could be due to bedding or the load, a combination of both, or of course the wind.

Let's assume the bedding is "fine" and look at the "harmonics" of the barrel, using a sine wave on an x-y coordinate as a model. We want the muzzle to be in exactly the same "position" for each shot, basically at either the top or bottom "flat" part of the sine wave, where a little variation on the "x-axis" has little affect on the "y" value. We vary the position of the muzzle on the "sine wave" by increasing/decreasing the charge, or by trying different powders. When we get the muzzle in the same relative position for each shot we generally get good groups.

Now this is where it gets a little trickier. We do not have a two-dimensional sine wave, we have three dimensional "sine wave". A particualr barrel may "whip" horizontally, vertically, or even in a "circular" motion. Thus, I think that just by changing the load, we can get verticle or horizontal stringing, or just plain bad groups.

Similarly, wind can cause both horizontal (crosswind) and, to a lesser extent, vertical (from your back/face) stringing. If I am working up loads in a crosswind, I usually ignore horizontal stringing (attributed to the wind), and concntrate on reducing the vertical spread.

The contour of the barrel has significant effect on group size - the lighter the barrel, the less "stiff" and the harder it is to get little groups. Here is an excellent, though long, article on barrel stiffness of benchrest barrels that may be useful:

http://www.riflebarrels.com/rigid.htm

There!, it's all probably as clear as mud now.

Seriously, I hope that it helps.

Bill

Same problem, same rifle except in .270. Barrel is full floating. The problem is not persistent, it comes and goes. It shoots better with Nosler's. I am thinking about re-barreling with a slightly heavier barrel. In this rifle the least bit of forend pressure will cause vertical stringing. I have varied my load a couple of grains (Re22/130 gr. bullet, mv 3150) with no great effect.
C.G.B.

Last week I had horizontl string while shooting a pair of 30-06, 59 gr. IMR 4350. Nosler 150 bt. Changed to a load of 62 gr. Rl9, same bullet and cured the 'problem'.

snowcat: Horizontal or vertical stringing can be the result of a variety of factors operating independently or together.

Horizontal stringing may be caused by mirage, poor trigger control, flinching, loads, bedding problems, or stresses in a barrel.

Vertical stringing can also involve the same factors but is usually attributed to bedding or barrel stresses or both combined.

Individuals can adopt consistent flinch or trigger squeeze behaviours which may make a group string vertically, horizontally or diagonally depending on the individual. The dispersion can be very consistent leading one to suspect the rifle. A rifle that recoils hard into a person's face often shows a diagonal stringing going right and down (assuming right handed shooter) or right and up as the result of the shooter unconsciously trying to move the rifle away from his face with his left hand at moment of firing. Alternately he may pull the rifle down with his left hand to protect his face not even being aware he is doing it. James Sweet has some interesting notes on group shape in his handbook on competitive rifle shooting that deal with trigger control etc.
With a light recoiling rifle that the shooter has no subconscious fear of it is most probably a barrel stress or bedding problem (which in itself creates a stress on the barrel). Rifles which have a pressure point in the tip of the stock are particularly likely to string vertically if there is a stress point in the barrel that reacts to the barrel heating up. Although we usually see shots walk up the target as a result of this problem I have also observed two rifles that walked their shots down the target.
An interesting question you pose as the answers though frequently found in the mechanics of the rifle are not always found there and may be caused by the shooter. Somehow, we all prefer to examine the mechanics first rather than our own technique.
On the other hand if they all shot in one hole every time who could be bothered?
luck in finding your problem.

A couple of observations, with a tip of the hat to the folks who have already posted their answers--good points, all, and I learned from them myself...

First. An aught-six Ackley Improved in a featerweight configuration brings two probable possibles to mind:

One, the light barrel will heat up extremely quickly in any temperatures above about 45 degrees F, and two, that rifle probably kicks like a pissed off stallion, whether you're prepared to admit that or not.

In the case of the heating barrel, I would imagine that two, perhaps three shots AT MOST can be fired in a five minute period before the shots begin to take a walk--this in temps over about the afformentioned 45 degree mark, and due of course to your rifle's thin barrel. That is my first best guess, that your barrel is getting hot. You can fire a couple of shots with a high powered sporter-weight rifle on a 70 degree day, and set the rifle in the shade for ten minutes and it will still be hot on shot number three, and shot number three will depart from the normal POI of the rifle. Heavier barreled guns are less susceptible to heating, but still require cooling commensurate with the outside temperature...

These are simply not warm weather rifles--they are designed to be light and easy to carry in the field, and to be used in the cooler months. They shouldn't be expected to shoot tight five shot groups, especially in June.

With a hunting rifle, the criterion should be where does it put the first two shots from a *cool* bore? That will be the maximum number of shots a *competent* hunter and shooter will ever need at one time in the field.

I will assume that you are dealing with the stiff recoil properly, and that that isn't the problem. Having another shooter test the rifle would settle this question (provided he was a good trigger man). And that wouldn't be me, by the way--I *hate* recoil!

I think what you need to do is to review your groups (you did keep and note your targets didn't you? ) and look for the load recipe that put the first two shots into an MOA sized group. If the thing is stringing from one end to the other and then filling in the gaps, I would suspect a bad load or bedding.

However, if it is stringing *progressively* away from the initial shot, then you're just heating up, and I would suspect the load is fine.

Take your best load out in the cool of the morning, (with your barrel already fouled and not cleaned from a previous range session) and see where shots one, two, and perhaps three land.

I think you'll be happy with your rifle's performance once you learn what it will do when tested under realistic conditions. What you have is an excellent working rifle which shouldn't be called on for menial target work. Check POI and load performance of course, but save that barrel for business!

Best of luck, and let us know how things go.

Dan Newberry
green 788

[ 06-07-2002, 23:23: Message edited by: green 788 ]

The one thing ive noticed is that the position on the cheekpiece of the rifle has got a lot to do with striging shots . try sticking a piece of tape on the butt where your cheek rests normaly & have a friend check the position every time you shoot. If this doesnt work then go to the more extreme accuracy flaws such as glass bedding etc.

Regards
Rudie

LIGHT WEIGHT RIFLES DONT SHOOT AS GOOD,IN MY OPINNION.BUT I HAVE A T/C ENCORE PISTOL THAT DOES THE SAME THING EVERY TIME I CLEAN IT WITH A BORE BRUSH IT STRINGS THE FIRST 10 OR SO SHOTS