I havve a factory 223 bull bbl that will shoot sub-MOA all day.
With 60grn V-Max it is good for deer. 40grn works great for crows.
I have several MGM bbls-- 7-30Waters; 357MAX; and 44Mag all in pistol bbls. All work for deer and hogs. I like the Burris pistol scopes in 2X or 1-4X vari.
I also have a factory 30-30AI bbl that will shoot 5/8" groups @100 with 125NBTs. Scope is the Bushnell 2x6.
Contenders are addictive and fun to shoot.

Coach