20ga Remington problems with scope

[Murby]

Hi,
I have a 20 ga Remington 1100 and have mounted a tasco scope to it using an AIMTECH mount.

My gun is a smooth bore bird hunting rifle that I'm trying to use for deer hunting. I'm firing 20ga rifled slugs and can't get the scope to zero in.

I made a wooden gun vice, rested on top of a 55 gallon drum and firing at about 100 feet.

I can't get it to impact at the same spot. Each time I fire, the round is going somewhere else usually 5 to 10 inches away.

Any ideas? I thought maybe the scope is somehow changing each time the gun is fired. Is it possible for the scope internals to be loose somehow?

I realize that rifled slugs are not exactly the most accurate, but we're talking 100 feet here.. not 100 yards.. FEET.

Thanks,

[swifty]

You need a solid rest.

~ Loose mount.
~ Loose rings.
~ Bum scope.
~ Parallax.
~ Comb too low.
~ Shooter error.
~ Target or point-of-aim too large.

[LCU1670]

Scope