From time to time I will get these angled strings, usually the width of the 'general' accuracy expectation but stretched out quite a bit. I have had nice evenly spaced groups followed by a group angled from 7 o'clock to 1 o'clock. Other groups have strung from left to right then a vertical string appears.

Today I got a 11 o'clock to 5 o'clock, 4 shot string in near straight line, 75mm long - that after getting a nice tight triangular, 3 shot group of 0.6 MOA. This with a rifle (303Brit) that in the past has alway produced evenly spread groups - a three shot group would always be triangular while a ten shot group would be under 1.25 MOA. Initially there was no wind on the range but when going back to the targets, there was a stiff breeze just forward of the bench shelter to just past half way to the targets, blowing towards the benches from about 15 degrees. Previous stringing also occured when the wind was doing funny things.

If I only knew

Bedding comes to mind first, then barrel stress due to heating. Then there is the question as to if the sights are walking around the action...

You could be experiencing fatigue.
If you hold your rifle with varying degrees of pressure from different points it will string the shots in response to the pressure of the hold. It may be scope or mount loose, or it might be barrel harmonics. If you have recently bought new components to load with you could try reducing the load slightly and see if that cleans it up. If that doesn't work the try increasing the load slightly (as pressure allows)to see if that cleans the groups up.

Always attempt to hold the rifle only as tight as you have to - in order to keep it from hitting the ground. Shoot when you are relaxed and well rested. Get up and walk away from the gun after each string and think about what happened. Breathe, relax and let the gun suprise you when it goes off.

When I start having trouble I always return to the basics - sight picture, breathe, relax, breathe, squeeze and count.

The scope is secure - it was loose prior to this. Bedding ? ... could be .... I'll check. Barrel heating? ... could be .... that could explain the groups getting worse in time. Fatigue ? ... mmmm .... could be that too. I was taking 'extreme care' not to pressure the fore-end. I placed my hand between the rest and the fore-end and only pulled the butt into my shoulder with my trigger hand and I took care to let the rifle 'surprize' me. I was also ever mindful of that scope smacking me on the forehead ....

quote:

When I start having trouble I always return to the basics - sight picture, breathe, relax, breathe, squeeze and count.

Good advise!

I forgot to mention that the fellow shooting next to me with a 308 experienced the same thing at about the same time. I should check that he kept his target ... mmmm. He has my rifle in his safe.

P.S. 308Sako, that is one beautiful rifle! I see it has a three point mounting like my Anschutz. I am shooting 55gr Hornady's in mine. Sometimes I shoot 60gr Hornady Spire Points.

The wind will do funny things. Also, if the scope was not installed with a reticle leveler and you are canting the scope at all when you shoot it, That will do funny things too. Add the cant to the wind and it's not so funny anymore. Resting the rifle on an overfilled sandbag or other hard surface will bounce the muzzle and result in even less funny things.

A very good book by a very good shooter, "The Ultimate in Rifle Accuracy" by Glenn Newick is well worth reading. It is aimed at beginning BR shooters, and not exactly new, but there is a wealth of information for all shooters in it.

quote:

A very good book by a very good shooter, "The Ultimate in Rifle Accuracy" by Glenn Newick is well worth reading. It is aimed at beginning BR shooters, and not exactly new, but there is a wealth of information for all shooters in it.

+1 for this book, I have read it about 5 times.

quote:

"The Ultimate in Rifle Accuracy" by Glenn Newick

I shall have a look for this book - thanks.

quote:

Resting the rifle on an overfilled sandbag or other hard surface will bounce the muzzle and result in even less funny things.

My rest is very soft and light. What about the squeeze on the stock? My hornet is easy - I just let it rest and then 'touch off' the shot. But the 303 has to be held firm on my shoulder. Maybe I should do my sighting in and load testing with a sandbag on my shoulder? Mind you, I often fire the gun from the prone position in the field. Although this specimen is ideally suited to off-hand shooting - long butt, forward mounted scope, heavy fat fore-end, high scope. This means my hold on it will be different for standing and lying (and bench) shooting.

quote:

The wind will do funny things. .....canting the scope ..... Add the cant to the wind and it's not so funny anymore ...

Canting I was aware of - I never before took the wind into account. It wasn't that much of an issue where I came from so now this is new to me - and very puzzling. At first I was blaming myself or my loads - even the rifle. Now it seems it's my lack of understanding of the wind effects!

Thanks for all the help!

I don't know the exact cause of stringing , I do know it happens different loads same day different out come .

Here is one of my Non typical targets ( As I used factory Winchester rounds for POI illustration ) #1 Fouler shot left low center , #5 Win. Factory , #10 hand loads center .

Aim point Dead Center on all rounds .45 -1.5 minutes between shots on all rounds .




It happens !. A dime will cover my hand loads from my Bushmaster and leave change .