AR15 - Which spring and buffer should I be using ?

[wareagle]

I did some parts swapping on an AR and was confused which spring and buffer is needed. Basically, I have a DPMS lower with a standard A2 stock. It is attached to a bushmaster 16" upper. Shouls I use the short spring and buffer or the longer versions? I thought I should be using the short versions, but I think it had long ones in it. I may be mistaken since I had a bunch of extra parts on the work table. any help is appreciated.

[molonlabetn]

When using an A2 stock and buffer tube, use the longer spring and buffer. The shorter combination is for the CAR telescoping stock.

If you're using the one which came with the AR you bought from me, the correct buffer and spring was already in the A2 stock assembly.

[wareagle]

I was ok withe the one I picked up from you. Its another one that gave me a surprise.

I thought that the "carbine" buffer and spring set was used for all of the barrels that had the shorter gas tubes (about every 16" and under upper excpet the BM "dissipater"). I guess you learn something new everyday.