I have a Contender barrel in .22LR. I have another in .22 Hornet, and another in .222Rem. I also have an XP-100 in .221 Fireball. (all 10" barrels)
I had a 14" Contender barrel in .223, but got rid of it, too long and too heavy for what it delivered. I think I've got "varmint pistol" pretty well covered. If I need more, I'll go to a rifle, .22 Hornet, .222 Rem, or .22-250.
I have a .223 rifle but its about useless for four legged varmints...I keep it for the 2 legged kind.
Personally, I have no interest in any bore smaller than .22. If you do, fine, enjoy! I just never found them worth the trouble.