Bullberry is the only one I`ve tried. I have 3 of their barrels, a .17 AH, a .17-223 and a .357 max. They are all excellant shooters. I`ve fired alot of groups with the .17 AH that were 1/4 moa or less. The .357 max. is a 15 in. pistol barrel and it will shoot 1 moa or alittle less. The .17-223 is the worst at about 1 moa., but I`m still working on it.