What actually MOVES when a scope gets bumped?

[Danman]

Not to throw a wrench in here but another factor in poi shift is not just possibly the scope but the air the pellet/slug is traveling in towards target. Pressure, density, humidity, updraft, down draft, etc. Definitely not an expert myself....I have set all my scopes as far as windage and then rarely if ever have to touch them. Was grouping my new tx200 last week with about 5 different pellets 30 yards. Many grouped well but the groups appeared in different spots on the paper. Ie the 10 grainers were low and left by a few inches. Low made sense but left? I always suggest find a pellet for your gun that just works and you use to verify in different settings.

 

[Bladebum]

Not to throw a wrench in here but another factor in poi shift is not just possibly the scope but the air the pellet/slug is traveling in towards target. Pressure, density, humidity, updraft, down draft, etc. Definitely not an expert myself....I have set all my scopes as far as windage and then rarely if ever have to touch them. Was grouping my new tx200 last week with about 5 different pellets 30 yards. Many grouped well but the groups appeared in different spots on the paper. Ie the 10 grainers were low and left by a few inches. Low made sense but left? I always suggest find a pellet for your gun that just works and you use to verify in different settings.

I think that's another good point that is very valid.

 

[Solo1]

Not to throw a wrench in here but another factor in poi shift is not just possibly the scope but the air the pellet/slug is traveling in towards target. Pressure, density, humidity, updraft, down draft, etc. Definitely not an expert myself....I have set all my scopes as far as windage and then rarely if ever have to touch them. Was grouping my new tx200 last week with about 5 different pellets 30 yards. Many grouped well but the groups appeared in different spots on the paper. Ie the 10 grainers were low and left by a few inches. Low made sense but left? I always suggest find a pellet for your gun that just works and you use to verify in different settings.

The left I believe is a change in barrel harmonics. A light pellet is going to put less lateral force in the barrel as it is being rotated than a heavy one

 

[Solo1]

Just found this pic on the net to give an idea of the number of parts in a modern hi power scope