Cause of Vertical Stringing in single shots

[tacotime]

I've read a few posts that said single shot rifles were prone to vertical stringing of shots on the target. What is the usual cause of this (assuming not the ammo), and the cure?

Thanks.

 

[Aggie01]

try this article:

http://www.bellmtcs.com/store/index.php?cid=439

 

[tacotime]

Good info, thanks. A lot of possible issues to check.