Our Avenger Magazine Models... The smaller sized 177-15/22-12/25-10 shot Magazines - will generally fit under most any scope rings The larger sized 177-18/22-15/25-12 shot Magazines - require high mount scope rings. If you're using a scope with a front bell larger than 44mm, the larger mags will generally fit under them. These mags are same height as the OEM Avenge-X large mag.
We designed the Avenger mags with a snug friction fit on the barrel to hold it in place. The OEM mags fit loosely and after 50 times, the fit is so loose the mag sometimes falls out. We oversized the grippers a bit to prevent the loose fit and to account for the tolerance we've seen between different rifle barrels. You'll need to firmly pop the mag into the breech with your palm the first time. This will allow the grippers to conform to the barrel and after a couple insertions the fit will give a nice easy snap in and work great. We tested the fit for 3000+ cycles.