What buffer weight in A5 extension for MK 12?

I noticed they were using H buffers in Carbine extensions.

I tried the A5 system. It did work but it didn't blow me away or anything. Went back to using regular mil-pec tubes, springs and H2's.

The A5 uses a different length tube and buffer. The buffer may weigh the same as an H buffer, but you can't use it with a regular carbine extension. It also uses a rifle action spring. I believe the weights are the same size, maybe someone can confirm this???

Run the heaviest buffer you can that reliably cycles your weakest ammunition.