RE: target issue
Whether or not people ' like' the gun, it should be capable of putting together groups at 100 yards. Like you said, you should let somebody else shoot a couple through it, probably with two or three different types of ammo. If somebody else can get your gun to, say even 4 inch groups at 100 yards, then it' s a matter of you working with your gun - practice and trying out different ammunitions.
If the other person you bring in has the same problems with a couple different types of ammo, then you have a problem with the gun.
The other thing you might try doing is just going to the range with that other person and seeing if you can group at 100 yards with one of their guns.
frizzellr' s question about the trigger pull is part of the practice thing - is the trigger so stiff or so light that you can' t hold a solid group? Since you haven' t said anything about it, I' d tend to think there wasn' t anything wrong with it.
Overall, I think you' ve gotten some good advice and things to look at... good luck!