The 22cal Pro Shot jag is 0.180" You can use it in the 22 and a 1-1/8" patch to wet with and a 1-3/8 patch to wipe with. Then use that same jag for 6mm and use a 1-3/8 patch to wet with and the 1-3/4 patch to wipe with. One jag, 3 patches covers 2 calibers!
Kim,
Sinclair sells a handbook for reloading that has a jag/patch size chart in the back of the book that is extremly useful. It lists all of the popular jags along with patch size and details whether the patch is tight, just right or needs to be skewered off center.