Gunsmithing POI walking causes

[badbot]

I was runing a couple of OCW ladders yesterday and as the veloicity increased the POI was walking toward 2 o'clock.
from 2500 fps to 3000 fps the POI moved over 2" right of POA at 100 yards.

I expect rising POI but the right drift makes me wonder whats going on.

thoughts? suggestions?

 

[former naval person]

Re: POI walking causes

Different exit point of the bullet from the muzzle as it oscillates. That is why you do the ladder then do grouping. JMHO

 

[badbot]

Re: POI walking causes

oscillation would be a bit random.
this marches right out the 2 o'clock angle.
barell has .1 float. so it is not touching

 

[Bugholes]

Re: POI walking causes

oscillation can be predictable, your leaving a node and moving to another. if you had the room on the pressure curve, you might get next groups high&right but looking good. I have a 338 LM that jumps 3" up and scatters when 300 SMK goes over 2800FPS- go figure. It does that with all powders tested, not just one combination