Umerex Beretta 92FS poor accuracy

[dhc8guru]

Maybe I am expecting too much out off this gun as far as accuracy goes but I figured this thing could hold more consistant groups. When I got a fresh cartrige of C02, I have to shoot double action just to get a 4" group at 30' with the occational wild flyer that won't even hit a 12" x 12" pellet trap. Once I get about 16 rounds on the C02 cartrige, I can go back to single action.
Its so spouratic though, shoots high, then low, left, right and then on center.I have tried several different pellets, mostly crosman premiers and gamo's domed and wadcutters. No difference, all shoot the same. All of my guns at least show some difference in accuracy between pellets.  My only other C02 gun is a Daisy 008 and it will outshoot this gun regardless of using pellets or BB's Heck even my new airsoft handgun will blow both of those guns out of the water in the accuracy department.

Anyone own this gun and have any advice on getting it shooting accurate?

[wrecktangle]

There are a bunch of Berettas out there; are you talking about the one that's around $200, and NOT blowback?

If so, I own one. I hardly ever fire it double action -- the trigger feels like it's 10 or 12 pounds. In single action from 10 meters with supported two-hand hold, I can usually keep most pellets inside a half dollar. It seems to like a lighter pellet, 7.6'ish or so. RWS Meisters or H&N Match Pistol work best for me. I didn't have a good experience with any of the Crosman pellets.

Added:
RWS R-10 Match Pistol also shoot very well.

[dhc8guru]

Yep, the non blowback version. I'll try your pellet recommendation. Thanks!