.308 buffer and spring

[emtnsocali]

aiiiiight.......im putting together my POF .308 lower and am curious what the difference is between a .308 buffer/spring and a ar-15 heavy buffer/spring combo.........i have the heavy buffer and spring combo for ar-15 already thats why i ask. thoughts??? will it work?

[ar15barrels]

It won't work.
308 cartridges are longer than 223 cartridges.
Therefore, the bolt carrier stroke is longer to allow the cartridge to feed.
The longer stroke requires a shorter buffer or a longer buffer tube.
In the case of rifle buffers, they use a shorter buffer.
In the case of carbine buffers, there are both shorter buffers and longer tubes.
The springs are also much heavier to deal with the extra weight of a 308 bolt carrier.

[emtnsocali]

copy that....thats why they make the 2 1/2" buffer for use with the standard ar-15 carbine buffer tube? thank you much!