New shooter question

After you run out of pellet 15 you start shooting 16. If groups from 16 are actually better then you start shooting 16 and save 15 for when you need pellets and don't have any 16s left.

Several things could be happening. Barrel is getting broken in or dirty. Gently clean it and try pellet that you zero'd for. Wind conditions same?? Also some pellets play havoc.

RWS is garbage out of my $2000 Daystate, shotgun pattern. JBS 18gr unlubed is scary accurate, hit a 1.2mm wide nail at 28 yards outdoors. Lube same pellet, no longer accurate as much. H&N, not as good, harder lead. FX WildCat custom smoothwist could care less lubed, not lubed, H&N, JBS, 15gr, 18gr, 21gr...(Havent tried RWS and HN Hornets worse than RWS in Daystate). Just gotta find what your barrel really likes after it is broken in. Clean it and dont force the shots, no such thing as flyers. Let them talk to you, how the pellet is mating with the rifling. I would zero for a heavier pellet, say 18gr JSB then try 15gr. Impact will be slighly higher but windage would be the same. These are .22cal of course, I dont know what you have.

If you think that pellet #16 is a strong contender, I would zero the scope for pellet #16 and shoot 5-6 10-shot group with them for accuracy. Even though they hit 3" high and left of the aim point and group well, they might group even better when they land where you aim. That may sound strange. Let me explain my experience:

I was doing some pellet testing with my Browning Leverage. Initial test was 10 different pellets, 10 shot strings, at 10 yards. I zeroed my scope using Ruger Superpoints, which did OK. I shot 3 different weights JSB pellets (14.35, 15.89, 18.13) using the same aim point, and discovered they all landed between 2-3" low and to the right of the aim point.
The 14.35 grain JSB group was loose at 3/4". The JSB 15.89 grain was much tighter at 3/8", and the JSB 18.13 grain was terrible and created 2 distinct groups that together, measured 1.75".

The JSB 15.89 grain were the best of the 10 pellets tested, so I zeroed the scope using them. The next 2 10-shot strings I shot measured .256" and .223".

Just my thoughts.

Lou