weather vertical or horizontal how do you tackle shot stringing?

i know ther is an element of human error especially on the horizontal, but is there anything obvious i am missing?

thanks

Morning Sir!
My SOP for shot stringing, is to check everything for loose screws, aside from the shooter. Determine if anything has changed with the firearm.
If you are shooting from a rest check that out. If you are resting the forearm of the rifle on a hard surface, you have found your problem.
Jim

If a known good rifle just starts strining shots one day, where before it had not I would check action screws obviously.

If it does it from right out of the box I would look at stock/barrel contact. Heat can also cause shot stringing.

If the gun/scope is mechanically sound.

Vertical: Change powder charge
Need to speed up or slow down the load.

Horizontal: Change powder/primer

SDHunter's advice mirrors my own experience. I have reloaded for two different guns that strung low and initial charges vertically but the problem was not seen with higher charges. But if this isn't a question of reloading and powder charges then check the mechanics. Also was the gun subjected to any dramatic weather changes that could have caused, for example, the wood stock to swell?