What is meant by Number of rifling grooves?

[Cabochris]

Could someone explain the difference between 3, 4 and 5 rifling grooves? I'll have JES re-bore a 30-06 to 35 Whelen and the number of grooves is a choice. When I asked, I was told 3 is good at a rate of 1-14 for the Whelen.

I envision more rifling down the Barrel with 4 or 5 grooves... and more grooves cost more. Are more grooves beneficial? What should I do/ask for on the re-bore?

 

[redale]

You have it figured out. 3 equals 3 rifling and 3 groves and so on. As for the number that is needed I have no idea, I would follow the recommendations of those who do the reboring.

 

[Cabochris]

I read 3 grooves is the way to go. I guess less pressure, easier to keep clean and longer lasting. So I guess 3 it will be.