Thanks, schutzen. I took the rifle to the range today and could not repeat that first tight group. I looked at the fore-end but didn't have anything to shim it with at the range. I was focusing on my 512 with suppressor for rabbit hunting. I could only get it to group with round nose Geco Rifle ammo. And it grouped! I'll try shimming both rifles and see how that works out. I'll probably have a look at the 511 too sometime.