i recently acquired a s&b pmII 5-25x56, with it a pair of arc m3 rings, i was wondering what the difference is between them, and the m10`s, are they the gen 4 model? is there any benefit to switching to the m10? i can say that i`m very impressed that i took them off, and there were absolutely no marks on the scope, kudos to arc for making a great product that actually does what it says, any help with my questions would be greatly appreciated