Are A2 Bolt Carrier Groups the same as M4?

[Monkeyleg]

In doing my research on M4's, I'm finding that it's a Franklin+ cheaper to get an upper without a bolt carrier group. I have an extra A2 BCG. Are the M4 and A2 bolt carrier groups the same?

Thanks for any replies.

 

[ny32182]

Yes, they are the same.