Sounds about the same as yours. At 15 yards, I was getting about a 2 foot group. Tried both cylinders, tried FMJ, handloads, Lead tips, jacketed HP's and best I got was about 18" with FMJ.... I was pissed as I'd waited 22 years to finally own one like I wanted. I called CS and they started balking and stated that it sounded like it was my shooting, but if I wanted to send it in they would review it. I sent it and got it back in 5 days fully fixed. They didn't give me a call or explanation, except that they had replaced all 3 parts. Now it'll shoot 1" at 15 yards and at 30 yards, I'm still sub 3" with most loads. My 6gr. Unique under 200 gr. RNFP leads are under 2 from a rest at 30.
So I'm quite happy. I'd like the 70 bucks back from the shipping, but it worked out. hehe I did learn that if I ever do it again, my regular dealer told me never to pay for next day UPS, but to bring it to him and he'd ship it for me. I guess from an FFL it's ok to mail it normal, so I'd give Ruger a call and let them tell you they'll cover parts if there's an issue. They will only guarantee 1.5" at 15 yards, but as I told them, "That'll do just fine!". Compared to what I had. hehe