Oh. That's comes down to the spring length and buffer weight. You can get the same effect with an A5 system using the longer A5 style extension tube, a rifle length spring and starting with an H2 buffer. Those are parts that will be going on my 308 build later this year.

Although, this also depends on the caliber. I don't like collapsible stocks on 7.62 or .308 rifles. They don't handle all that well, imo.