Buy the 22 barrel (10") and a probe from Mellon. Now get a plastic breech. All set for 22 conversion. Only two screws to deal with. I suggest a stainless steel breech screw to replace the pissy gonna strip the head allen screw.
Another solution may be get a Beeman 1073 rifle. Barrels swap out with .177 and .22. $98.00 at walmart. Much more power, better trigger than a Crosman springer even with an after market trigger, and when the job is done back to .177.
Get both! Dave