It's one of my common bugbears down at clubs... new shooter turns up, really struggling to hit toffee... look at pellets, and 9/10 times they are something cheap (which understandable for new purchases) and rubbish... if they're of the same calibre of my rifle i normally chuck them a load, and magically they start hitting things. JSB's go well even in the cheap chinese co2 things... and whilst most shooters are concerned with pellet on pellet at 55yds, they're more than happy when they suddenly get 1/2 group at 20yds off the bench with something they've previously been struggling to get 1/2 foot groups with before.
Despite knowing the issues about some guns liking some rifles, why the mags don't do a comparison test between pellets I don't know.
Beyond that, in the esoteric world of FT/HFT/Bench then you find gems of knowledge like the head size nonsense, which has been proven as such and the importance of batch.
We really should start a group thread...
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep