Barry, Sorry the site ads here suck up the bandwidth and lock my comp on Firefox or IE. I don't come here much now.
Try a 3/32" .093 port first on the 7.62x40, avail at any hardware store. If that doesn't work you can step up to a #38-.101 if needed to run H110. I would run a standard weight buffer and spring not a H1 or H2.

"I threw a touchdown pass in the last minute to win the state championship game. I know it was 30 years ago and not relevant to this discussion but it makes me important and believable, it's the only great thing I even accomplished"