All parts in interchangeable. I have switch pumps, hammer, springs, receiver, stock, they will fit. Only difference is 2200 is in .22 cal and 2100 is .177. these muti pump isnt that powerful. Even the .177 is only going 600-630 fps. I used to have a 2200 10 years ago. But never tested it's speed. I'm guessing 400-500 fps. That's why its discontinued. Not many people were interested in a weak .22 when there are many cheap .22 that is twice the power or even more. If you need parts for your 2200. You can used parts from a 2100.