This is what I wish Kel-tec would make...
I was just goofing around mocking it up. I envisioned a "compact" version of the PMR30, maybe a PMR21. IT needs a shorter barrel and about 2/3 grip. Reduce the flush mag capacity to about 20 and done. The 30 rnd. mags should fit too.
I think it would sell like hotcakes. A 20-shot .22 WMR about the size of a Ruger LC-9, or close, that is 10-12 oz.