Prone advice - Vertical stringing

[j-team]

I'm having difficulty with vertical stringing when prone with sling.

I know the rifle shoots OK as I can get nice round groups off a rest so it's something I'm doing (or not doing).

Any suggestions? BTW, I'm really a pistol shooter, I'm just dabbling in a bit of prone for a while.

[ShootingSight]

If you are shooting irons with a front post, vertical stringing can be a sign that you are having vision difficulties, specifically presbiopia. If you are around 40 years old, the ability to focus up close suddenly disappears and you need reading glasses. Well, it's not just reading, you also need glasses (albeit much weaker) to see the front sight without straining your eyes. If you do shoot without glasses and just let your eyes strain, the focusing muscle, the ciliary, becomes fatigued, and you start getting inconsistent focus. Inconsistent focus leads to vertical stringing with a post.

[Tim S]

Ok, I'm presuming aperture sights here, so top faults for a beginner would be:

Breathing - not firing at the same point in your breathing cycle.

NPA - not establishing a good NPA

Butt - insufficient pressure in the shoulder

Bedding bolts -too loose

Cheekpiece - wrong height, so head supported by neck.

Eye relief - too short, so neck cramped and moving back forth.

Crappy ammunition with a very large velocity spread could also be a cause.

[j-team]

OK, thanks.

Not eyesight, bedding or ammo as I can shoot OK from a rest.

The comment on there not being enough pressure from the butt in the shoulder is something I have considered, would shortening the sling help that?

[Pat McCoy]

More likely to help if you lengthen the buttplate, or if not adjustable, move the handstop slightly forward.

[Martin H]

PM sent
Cheers Martin

[Tim S]

OK, thanks.

Not eyesight, bedding or ammo as I can shoot OK from a rest.

The comment on there not being enough pressure from the butt in the shoulder is something I have considered, would shortening the sling help that?

Maybe. The sling needs to pull hard enough to hold the rifle/forearm up and keep the butt securely in the shoulder*. I'd certainly try shortening it a little - close spaced holes are very useful here. However be careful the sling isn't too tight, or your right shoulder will be tense; this causes erratic recoil. Top shooters invariably have a tight position, but they train regularly and have the skill/self-awareness to stand more pressure. I think it's something to work up gradually.

Also check the shoulder of the jacket isn't loose, as the butt can slip. And ensure you're using the handstop properly; moving your hand back and forth can change elevation. I'd lump keeping your left arm relaxed in with yhis.

Poor head position is a major problem for beginners IMO.

Free Rifle hook butts offer more surface area, and the facility to get the plate exactly where you want it, but aren't a substitute for correct sling tension.

[beye]

Lack of follow through can let the rifle droop slightly -- doesn't take much. Also hurrying the trigger often results in low shots. For myself, I find a hard cheek weld (as is common with HP shooters) gives me verticals, as I cannot apply the same exact pressure every shot in long match. A smallbore rifle doesn't have much recoil, so it can be redirected more easily than say, a .308. More downward pressure gives high shots and less gives lower ones, depending on how much cheek pressure is used in obtaining a zero.