Originally Posted by The mielke way
I bought 100 of the 17-70 and 15-70 for like $15.00 and replace them every time I play since they are the only dynamic orings. cant get much cheaper. And with the HNBR I never have leaks. Just make sure they have enough in the inventory column to the right.
12/70 on the bolt guide and 16/70 on the bolt sail are dynamic as well. That is a great find and I will be buying those therban orings here soon.