All of them can shoot well. If you want the Ultra Varmint fluted, then that is what I would get. They are offered in 204, 223, 22-250 and 243 and all have 24" barrels. 300 - 350 yards is stretching the 223 a little, but doable, any of the others would be a good choice too. Personally, I think I would go with the 204 in the Ultra Varmint fluted, but that is just me. Just be warned that IF you have fore end problems, the synthetic fore ends are not as versatile as the wood fore ends to make adjustments to. I have a 223 Ultra Varmint rifle with the laminated stock and fore end. I have a weakness for the laminated woods, but that is a personal thing. Good Luck and Good Shooting