Moderator Mystery

[JackHughs]

A friend recently bought a Benjamin Kratos from AR. He also purchased a new Donny moderator and the proper adapter to mount the moderator to the Kratos shroud.

He mounted a NIghtforce scope and we went out to the local range to sight-in yesterday. With the moderator installed, it was impossible to sight-in at at any distance. At 100 yards (the backstop), shots were dispersing as much as 6 ft in all directions.

I then removed the shroud and mounted the moderator directly to the barrel, which is properly threaded - no adapter needed. The results were the same.

Without the moderator, the rifle shot 3/4" groups at 50 yards and was easy to sight-in at 100 yards.

We both inspected the moderator. There were no visible sighs of clipping. However, neither of us has any past experience with moderators.

Any thoughts?

JackHughs

 

[jackp_MDB]

I would initially check to see if the pellets are "shaving" as they go through the moderator. You might see some led traces in the baffles or the entry/exit areas?
Moderators do alter the barrel harmonics also, but I would not expect to see as much dispersion as you describe.

 

[WorriedMan]

Not an unheard of phenomenon, reason why many use a next higher caliber moderator than airgun. Never a problem with moderators that came from factory for my AGT and FX airguns, can't say same for aftermarket ones. WM