Will post video. The legendary company that has made delayed roller blowback HK style rifles is in the suppressor business. The three options that are out sound very good.
Yeah, and depending on what round is being shot, any extra elevation is there if he wants to go out to a mile. I shot Hornady Match 147gr ELD-M 6.5CM and 23 MIL's got me to a mile out of a 24 inch barrel. Rather have and not need than to need and not have! Especially if they're about the same price.
Only thing about that model is the low elevation adjustment range. I'd go for the 4-25×50 for 40+ mil elevation! Glass is Schott glass and should be good.