Tac 10 & Tac 15 common parts

[gelmir]

I have a Tac10 upper on the way. Can anyone tell me what parts are common with both? I know that the arrows (bolts) are not the same but what about the limbs? I would assume the strings are not (shorter on the Tac10). I have read that the Tac10 is to be discontinued and I would like to stock up on non common spare parts.

Thanks.