this is for the 22lr croud and the 22 mag. croud

[Rocky Raab]

Welcome to HuntChat and the rimfire forum, dogman.

There IS some truth to it. But it isn't necessarily an issue of "lead filling in barrel imperfections."

The .22LR shoots very soft lead bullets at a moderate speed. There normally isn't enough velocity or powder heat to cause the leading that's common is something like a .357 Mag.

But there are subtle relationships between the bore, the bullet, the powder and bullet lubes used. The effect is a lot like the way a cast iron skillet gets "seasoned" by foods and oils until it becomes almost stick-free.

Shoot one particular kind of ammo in a gun for a while, and the bore gets seasoned to that load. Accuracy improves and stays good as long as you stick with that load.

But change brands or types of ammo, and things go to pot for a while. Ten, 20 or 50 shots later, and all is back in the groove again - no pun intended.

That's why some competition rimfire shooters refuse to clean their bores - ever! They shoot the exact same ammo (often even the same lot number) exclusively.

Finally, all this doesn't apply as much to the .22 Mag. The WMR uses unlubed jacketed bullets at a bit higher speed. So go ahead and clean your .22 WMR as often as you like!