Vertical stringing ?

[.358]

Did a little shooting with my Bar's yesterday. One shot fine the other started stringing shots up some almost 6-8 inches above sight in. Can't figure it. I had the one cleaned by a local smith and I noticed the front swivel stud was not locked up tight aganist the larget nut on the forend like my other one. Would this make a difference ? I always seem to have this delima is it the scope or the rifle ? I think the scope is ok, worked fine on my son's rifle, there was no left to right movement just up and up. The bbl wasn't hot and it was a cool day yesterday.[:@]

[Danny45]

Were you resting the rifle on something?

I've noticed that when I make a shot from the bench and it isn't where I think it should be, I bear down subconsciously on the weapon. Now with bolt guns that isn't a problem if they are freefloated and I'm not resting the barrel on anything. But on a BAR or other type of firearm, it could cause you to start stringing upward. I don't see how the sling stud being loose could cause that. Being too tight and touching the barrel can.

Cheapest thing to try is another scope if you have one laying around. Then you'll know for sure if it's the rifle or the scope.


Good luck and keep us posted.

[Gobbling Buck]

What type of breathing rythem do you use when shooting? I know a lot of people that will tell you to inhale then exhale halfway then shoot. There is a problem with this, you will never exhale the same shot for shot. You should always fire at your natural respatory pause that occurs between breaths naturally. If you were breathing during the shot, that could contribute to the stringing. Also, resting your bbl on something will affect your bbl whip that occurs when the bullet is forced through and causes the metal to stress. Was the ammo free of defects? I had a problem with some rounds hitting erratic and noticed the cone of the bullets were getting buggered up on a carbon deposit on the feeding ramp of my rifle. Good luck and hope this helps.

[Nomercy]

I'm kind of betting that you didn't allow your rifle time to cool between shots, your forestock retains heat in the bottom of your bbl, so it'll stay expanded while the top of the bbl will cool and contract, making the bottom of the bbl longer than the top, making your bbl begin to point upward farther than normal. That's probably the biggest increase I've ever heard of, 6-8" that is, but I've heard close to that on a few occasions.

You said your bbl wasn't hot, and that's why it happened, if the bbl runs hot, it's probably pretty close to the same temp throughout, but if it's cool to the touch, that allows there to be the biggest temp difference between top and bottom of the bbl.

It could also have something to do with your lug scews/bolts, if they're not tightened properly, they could be producing a torque in your rifle that might get changed with subsequent shots, it's pretty rare that it would ONLY shift upwards though.

One thing that I'm kind of thinking about-VERY VERY VERY RARE-I've only ever seen it twice, one a ruger and one a ML...if your gun had a TERRIBLY worn bbl, or was badly over bored, your bullets are too small for the bore, your first few shots fouled it enough to get your bullet to seal up better, and your velocity increases substantially from it, 6-8" is a HUGE jump for this problem, but it's possible I suppose...I've got an over bored ruger that takes about 3 fouling shots-first three will be 5-8" group about 3-4" below the bull, the rest of the shots are .5-.75" groups right on the bullseye...it's a .30-06 with a .3105" bbl, almost like it was bored with a worn .311" machine...slugging your bore would tell you if this is the problem.

[slugman]

if your using a scope make sure the rings are tight

[GATurkHunter]

From my experience I'd have to agree with Nomercy. I've found some rifles to string vertically as the barrell gets hotter. Let it cool and your back to the origanal shot placement. Could be something else but thats what I would bet on and its fairly easily to figure out if that is what is doing it. Allow a few minutes between shots and see what happens.