My open .22 steel pistol is an older (80's or 90's) Ruger Mk II with the following. Tacsol 6" upper with Tandemkross comp. C-more railway with an 8 moa dot, exact edge extractor, a no longer in production Clark trigger and hammer bushing, VQ Ti. X-fer bar, sombody's mag release, some kind of extended bolt release and Hogue wrap around grips. I have been racing this pistol for about 10 years and the only time I had problems is with Remington gold bullet bulk box ammo. I have used four different comps on this pistol starting with the VQ that clamped on the stock bull barrel this worked well. Second was the 36 hole Tacsol, another good comp. I thought about having the holes taped so I could "tune" it but never did. Third was the Tacsol steel comp that is for their conversion upper, works but puts wieght on the barrel end and is slab sided. I just recentley bought the Tandemkross, I have not yet shot it as my work schuedule has been nuts lately. Here is an older pic.