vertical strings

[Buck 89]

what causes vertical strings?

 

[gpoldblue]

Buck89....Vertical can be caused by ALOT of things...shooter problems,gun(mechanical) problems,load problems,ambient condtion problems,etc or a combination of problems. If you can,I'd suggest you acquire a copy of "The Book of Rifle Accuracy" by Tony Boyer. I got my copy from Bruno Shooters. On pages 317 & 318,Tony Boyer lists 15 different causes of vertical. Good luck.

 

[BoydAllen]

What sort of rifle,caliber, rest and bags, and shooting style?

 

[Buck 89]

I shoot 6mmBR and 308. I use an IRA bipod and rear bag with heavy sand in prong position.

 

[BoydAllen]

Pardon my ignorance, but what is prong position? Oh wait, that was probably a typo. I presume that you meant prone First thing, are you shouldering the rifles solidly? Second thing, have you tried something else to support the rifle in front to see if it is a bipod related issue. Third thing, does your rear bag have some give? Rock hard rear bags can cause problems, there is a tendency for shooters to want to shoot with as light of a hold as they can, and still pull the trigger without moving the rifle. Often this approach is the problem.

 

[jbpmidas]

Prone, I would imagine.

 

[FroggyOne2]

Boyd,

It is the new prone F-Class position.. keep up with the times man..

 

[Buck 89]

Type error, sorrow about that.

 

[Anton G.]

Causes of vertical stringing that I have learned from:

1. How the rifle rides the bags from shot to shot.
2. How the shooter holds the rifle, or changes in hold from round to round.
3. Velocity changes from round to round (many causes for this issue).
4. Temperature changes.
5. Wind increasing or decreasing from directly ahead or behind the shooter.
6. Bedding problems with the rifle.
7. Poor marksmanship.
8. Loose scope, rings, base, or internals in the scope.
9. Changes in the pressure the shooter puts onto the rifle from shot to shot.

#3 could have a host of causes, for example
-changes in neck tension from case to case
-variations in case weight
-variations in length to ogive on the bullet
-variations in powder charge weight
-variations in case preparation from case to case
-slight variations in bullet weight (.1 of a grain or more)
-when the shot was fired in the string (shortly after or before cleaning)
-temperature of the barrel from shot to shot as barrel heats up and expands

and there are many others, but those are the ones I find most common.

 

[Buck 89]

Thanks for the info.