Re: Horizontal Stringing
As mentioned, it could be a number of things.
You are getting to far ahead of yourself too quickly.
In my opinion the first obvious reason in horizontal stringing is trigger control. You can not troubleshoot any further until you are absolutely sure that you have your trigger control down and you are not pulling or pushing it off. You can not anticipate the shot, and you need to follow thru.
The next thing you need to critique is your shooting position and a natural point of aim.
Make sure you have the operators basics down first before you get into the technical issues of the rifle and your loads.
Everyone wants to always blame the rifle, loads, or shooting conditions, before they think about operator error.