Have an old 2200 I picked up a ways back at a gun show.
Loved the ergonomics, but I couldn't get the soda straw bbl to group worth beans. The plastic bolt on it would blow open anything over 7 pumps...

Found that the rear of the 2200 valve is almost 1/2" longer than it's 13-XX counterpart, so....



There's a part comparison.
I threaded on a 13-XX front to the 2200 rear, and ended up with this after quite a few other mods:




It actually works quite well, despite the aged and worn 2200 valve rear. Stem is getting a little wonky, but still decent.

10 pumps averages 569.8 fps over 10 shots with an extreme spread of 9.9 fps with the 14.3 gr Daisy hollowpoint.

15 pumps (and I dare not go further until I can get a new valve into it) yields 675.5 fps 10 shot average with an extreme spread of 10.0 fps with the same pellet.

That small increase in valve volume is working wonders...

Regards,

Doc Sharptail