buna, viton and hnbr are just different materials used to make orings.
typically, buna's wear out quicker. but are much cheaper.
hnbr orings are 70's (which is the hardness or rigidness of the oring, the higher the harder :-) ). and are green. last longer than bunas.
buna can come in 70 or 90. and are typically black..
viton can come in 75 or 90. and are typically brown. these are the most expensive orings, and last longer than bunas as well.
the higher the number the tighter the fit usually as well.
but you can use any of them for just about any oring in your marker. all that matters is if it is the appropriate fitment.
quad orings aren't recommend for most paintball markers. i never use them atleast. they are slightly different in design than other orings. they are in the shape of and X rather than round. they also are better at preventing twisting in the grove they sit because of this design.
"Mess with the best, Die like the rest"
Last edited by Nexxux : 04-19-2012 at 02:37 AM.