.550" vs .600"?

[RichCoyle]

Do you experienced shooters think there would be any difference in cold bore shot with a muzzle diameter of .550" compared to a .600"?

I have an 8mm magnum with a barrel diameter of .600". The other da I fired a cold bore shot at 300 yards and then a follow up shot as though I was hunting. The "group" was 2 1/4". I'm thinking about a new 7mm magnum and using a .550" barrel. Could I expect that kind of performance with the lighter barrel in 7mm?

 

[lancetkenyon]

Going from a light sporter to a Featherweight in 7RM?

Pretty light contour for my taste.
I would prefer a #2b to #3 at least. Or a #4 CF.

Should be OK for a cold bore hunting rifle. Might start to move for the 2nd shot, probably more walking on shot #3.