Testing Different Loads Question

[370bc]

I wanted to check my zero the other day after I bumped my scope.
I cleaned my barrel and shot a great group with an old load that I now use for fouling shots. It shot under MOA @ 200 yards with the first shot going low @ 7 o'clock.
I then shot my go to load that haas shot half MOA on serval sessions. It grouped well over MOA.
After that I rezeroed my with an entirely different load that also shots half MOA.
It shot under MOA but not half MOA.
My question is, after shooting a load with a certain bullet and powder, and then switching to a different bullet and powder, the fouling from the first load would possibly affect the group size in a negative way because they are different fouling types?
Should I just run a bore snake to take out some of the fouling, or start completely over with the normal fouling routine? Thanks in advance & happy
holidays!!
The barrel is fouled with 15 shots.

 

[hogpatrol]

Did you also change bullet brands?

 

[370bc]

Yes. The only thing that remains the same was the primers.

 

[CPorter]

Changing powders, sometime lots, changes your POI and sometimes takes several shots to settle in. Bullets and primers do too. Sometimes if the components are very similar the change is not pronouced. For my loads I have switched between Fed 210 and 215 primers and the POI didn't shift but the dispersion did. Changing between IMR 4350 to 4831 or 3031 has taken up to 10 shots to settle in.

 

[LHSmith]

If you did not use wind flags (ribbons) your results are meaningless.....unless you were shooting a .700 BC bullet @ 5000. ??? Seriously, you need to KNOW (not guess) what's going on out there (esp. @ 200 yds). You shot a minimum number of rounds, in unknown conditions.... the difference in results if you had cleaned between groups would most likely be indiscernable.
I at least like to run a wet patch through when changing powders...and even then I'll the identify that first shot by marking the bullet with magic marker to single it out from the rest of the group.