AZ_CZ,
I am going to ruin my reputation and loose what little credibility I have had on this forum by offering the following...
Lead will build up in the barrel. You may have to actually clean it. I know lots of folks with very smooth and lapped factory barrels don't have to clean them, but a standard production barrel with chatter marks might actually benefit from lead removal periodically.
I check for lead buildup with a borescope. When the borescope lens tube won't go more than half way down the barrel without getting jammed in the lead, I clean it. Or you can try dropping a .177 pellet down the barrel. If it won't fall out the other end, you should probably clean it, or at least get the pellet out.
Seriously, I need to clean my 22LR Savage much more often than I have been. I waited too long last time. And I am going to use some JB paste to smooth it out some too. And I'm going to clean the leade area very, very, carefully.
In my mind, a 22 rifle is more cantankerous than any other firearm, due to lead and ammo variations, in addition to variations in the bore finishes and dimensions between manufactureres.
I'm glad you have a shooter. I am taking my "clean" Savage out this afternoon.
Joe