Home Forums Hunting & Shooting Custom Rifles & Wildcats Number of groves custom barrel?

The 3 groove barrels are very hard on thin jacket bullets. I agree there is no upside to them.
I have a 12 groove barrel that went for ever and shot great. I mostly get 5 groove now

got these in for the 300 Razor & 300 Headhunter builds, all 5R , 30 cal 5R cut rifled barrels seem to love the long arse, heavy, high bc copper bullets

these two 32" Rock Creek tubes are also 5R with a bit faster twist at 7.2 tw

...,,

this 32" 1:7 tw 8mm barrel has 6 grooves, just right for the 256 gr Cutting Edge MTH bullets

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I remember the arguments that arose over the two groove vs four groove barrels on the 03 & 03A3 barrels. Many thought the four groove were better, others argued the two groove was better for cast bullets. I was not convinced one way or the other.

I was planning on a re-bore on a 30-06 to a 35-06, just because it was less money than a four groove.

This thread is the first I’ve read any opinion regarding a three groove being worse than a four or five groove.

I know that the marlin micro groove barrels shot jacketed bullets well but not cast. They eventually offered Ballard style
Rifling to shoot cast. More grooves are easier on bullets. Seems like Shilen used to have 8 groove but i could be mistaken

Never noticed a difference between 3, 4, 5, or 6, but my 3 groove barrels are all on calibers for which I do not shoot thin jacketed bullets. It seems to be a fairly common experience that 3 groove barrels in smaller calibers at higher twist rates are pretty hard on thin bullet jackets.