my grouping sucks!

I have a ruger blackhawk elete springer, I'm happy with most things about it, but I can't get a group less than six inches at 25 yrds.I'm using a center point scope, the "artillary hold", and whatever. I don't know if I'm using the best pellets, but I should be getting a better group at 25 yards. Is there something wrong with this particular gun? I have only put about 1000 rounds through it, and I know the gun needs time to "wear in", but six inches is just too big of a group. Is there anything I can do to improve it? THANKS
 
What pellets are you using?
What caliber is the rifle?
Have you cleaned the barrel?
Can you post a picture of the groups? It might help determine the issue.
Does your scope mount have a stop pin?

Checking the o rings would be a great idea as well.
There are so many variables with issues like this. Photos and more information would be needed to narrow it down.
 
"What kind of pellets are you using" has already been asked, tho not answered. How about: "are you using alloy/hobby pellets?" Lightweight pellets deliver much higher velocity, and usually much "suckier" groups than lead. If you are using lightweights, try lead. The Ruger line all seem to deliver "magnum power" on paper, so I would suggest shooting something in the 8 to 11 grain weight (assuming your rifle is .177), and 16 to 18 grain if it's a .22. Lighter weight pellets that travel in the high 900 to low 1000 fops tend to destabilize as they lose velocity, and "corkscrew" or tumble. Also, the shape of the pellet can contribute to accuracy issues (though not usually at close ranges like 25 yards). If you're using wad cutters, try domes or pointed pellets.
Artillary hold: figure out where the center of balance is for your rifle, and place your support hand under it. Shoot a lot. If your groups don't improve, move your hand forward or back a bit, try again. It takes a lot of practice and experimentation to get it right. When I first started shooting sprinters, my groups at 25 were atrocious! After I don't know how many shots (a lot!) I got my groups to shrink up considerably by experimenting with changing position of my forearm hold, but they still weren't great. Once I bought a Chrony, I saw that my "1200 FPS" gun was actually only hitting about 700 FPS. I rebuilt it with a new seal, and suddenly it was shooting in the 900s, and putting pellets on top of each other. You may consider doing that as well.
 
As mentioned above, try different pellets, check your stock screws(there's one on each side near the barrel pivot and one or two in the trigger guard). If you're using a scope make sure it's not moving due to recoil-put a strip of tape on the gun and on the scope in front of the ring or mount. watch to see if either the scope slides back in the rings or the mount slides back on the gun. If there's movement the rifle will never group well until you stabilize things. Make sure your scope is rated for a spring piston airgun, the two way recoil of a powerful springer will destroy the toughest firearm scopes.
Good luck, the Ruger Blackhawk has a good reputation, so stick with it.
John