If you don't test to see which pellet shoot the best with which airgun....you would never know what went wrong with that bad shooting session....bad pellets, bad day, bad airgun?
All most all of my shooting (including PBs) is done offhand with open sighted pistols at either 30 or 50 feet. I'm oldish and shakey with bad eyes and I'm pretty pleased when I shoot a 2" group.