MemberMay 19, 2016 at 12:36 am21 Bullseyes
I don't know for sure if the low ss tac rings and stac 4-20 combination will clear the front bell on a heavy barrel, I am guessing it will but you may have to check the numbers a bit. Remember I have not personally used the Sightron yet, but their other products and generally good reviews give me a positive impression. I did read one negative that had to do with a broken/defective from the factory stac and a retailer with poor customer service.
Anyway, have fun with the research and good luck on a speedy delivery.
btw, I think “marquee” ammo would probably be the stuff the store advertises on it's marquee to bring in the bargain hunters, i.e. inexpensive “plinking” ammo.