Much of a firearms personality has to do with ammo. Doesn't matter if it's a rifle or pistol. As an example, my Tisas 38 Super shoots shotgun patterns with one brand of ammo, and then 1 1/4 inch groups at 25 yards with two others. For my rifles, each has it's own favorite factory load as well as hand load. I always find a factory load for each of them so if I have to buy ammo when out and about there is always an option. That is not always the case with hand loads. For factory loads different lot numbers may affect accuracy, but as long as it's the same brand and bullet the zero shift generally will not put you out of the kill zone on a deer size target.
One thing that I have learned since I got a Garmin is that the velocity spread with cheaper ammo is much wider than with higher quality ammo. It is not so much noticeable at the ranges most people are shooting handguns these days, 5 to 30 feet. Once you pass 50 feet it does become noticeable. I am reluctant to name, names here, but as an example Freedom/Lax 125 gr ammo does shotgun patterns in my 38 Super, but is very accurate in my 9mm firearms. Conversely everything shoots great with Aguila 130 gr and Stacatto 138 gr match is fantastic. The difference is the velocity spreads between shots. Freedom/LAX vary up to 75 FPS while Aguila varies up to 30 fps with Stacatto at 25 or less. My handloads in 9mm and 38 Super vary 20 to 35 FPS dependent upon the powder and bullets used. For rifles the difference is even greater. In my 308 for example one brand of MATCH ammo varies up to 120 fps while Federal Premium 165 gr hunting ammo only varies 40 fps. Lets talk for a second about the variation in the supposed match ammo at up to 120 fps. The speed of the bullet affects bullet drop as well as wind deflection. There are other factors that play in this case that I won't bore you with the others, if interested PM me, The result of this much variation is large patterns, with the slow bullets dropping and dealing with wind deflection greatly.