Love my 455. Shoot just as good as slg's cooper. Definitely a yo Dave kit, metal mag well, and extended mag release. Mine feeds great with plastic and metal mags. The best ammo through it has been Norma tac, with cci sv, and eley subsonic hollow points very close 2nd place tie. The switch barrel works great, but my 17hmr barrel is a little picky. Hates vmax, but loves tnt and gamepoint. The 17 also doesn't feed as great as 22lr but feeds good enough. Very accurate gun. The only complaint is bolt throw is way to high and buying rings can be a ordeal at times due to this. I am going to have mine machined and cerakote to solve the problem.