They won't fit in the mag unless it's the shorts which I never found accurate in anything I tried them in.
You could use regular polymags by hand loading without the mag. I tried once and the results were not as good as with JSB or H&N pellets but they are ok for short range hunting. I judged them to be not worth the effort.
Every gun is different so the only way to know for sure is give it a try. I find H&N hunter extremes to be every bit as lethal as the polymags but with greater accuracy in mine.
In fact, a man owes it to himself to try a broad range of pellets before deciding which is the go to ammo in every gun he owns.
My 22 and 25 Crickets shoot the 16 gr Polymags, I did the Zonk mod on the magazines not sure if that makes a little more room. The Zonk mod is one O ring in the mag, So the mag does not fall out of there holders , They fit tight, Mike