18" Barrel
I'm thinking of creating an upper for my AR using the 300 Fireball chamber and an 18" barrel. I want to do something similar to an SPR look. Stainless with rifle length rails and flash suppressor. This will be a pig/deer killer and I want as much velocity as I can get but not with a 20" barrel.
Does an extra 2" help any with velocity? I'm in a no sound suppressor state so subsonic loads are not of great concern. My real intrest was a .30 caliber rifle that is lower compatible with a standard AR15. Anything special I need to know to build this?
TIA!
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