Gunsmithing Rifling Types and Accuracy

[lw8]

I've read in several places that certain types of rifling are more accurate in specific calibers. For example, several people that should know have opined that 5R rifling isn't optimal in .223 caliber rifles and that standard 3 or 4 groove would be more likely to produce an accurate barrel.

Is there a list or guide for which rifling type is optimal for each caliber?

 

[JJones75]

I've had several rifles chambered in 308 , one Lilja 3 groove , one Obermeyer 5R , a Kreiger 4 groove and the current is a Bartlein 5R (tight bore) and they all would shoot in the .2's with hand loads from a bench rest (probably better with a better shooter) I can not say one shot better than another.
I've also had a 6mm BR chambered in a 3 groove and 6 groove Pac-Nor and currently a 4 groove Krieger and they all shoot better than I can the latest one is the most consistently accurate but its alot heavier barrel threaded to a Bat action where the other two were Rem varmit weight barrels on a tried Rem 700 action

 

[xringaccuracy]

Built more rifles with 3, 4, 5, 6 grooves and none seem to shoot better than the other. The bigger thing is ywist rate for the chosen caliber. On a final note, get a well known brand, regardless of groove number, it will shoot.

 

[my human host]

Frank Green has made some good posts on this topic. I'm not sure I could dig them up so hopefully he'll chime in.

 

[lw8]

Yeah, I searched and didn't find anything definitive. Specifically, I found a few posts advising not to use 5R rifling for 6mm or below and I was going to order a barrel for my 5.56 SPR.

 

[pinsandpitons]

Why no .22 cal 5r?