yup I want 1:12 as well. but I want 5 groove. everyone says 3 is fine but Im trying to learn what the differences are. how many groove are you getting if re boring? or do you know much about that? I can't seem to find much info on the 35 and what the difference is 3 vs 4 vs 5 groove.
Well, I’m not an expert by any means, but any choice regarding the number of grooves is going to be somewhat of a compromise. I read a Practical Machinist thread which stated that the number of grooves does not affect stability and that there is little practical difference in accuracy; however, I also read (in the same thread) that different calibers in different rifles will sometimes favor a certain numbers of groves, but I am not certain how this manifests itself – possibly in accuracy. It seems as though ultra long range shooters favor 3 groove barrels, but I’m not sure why, though I can speculate that it’s likely accuracy.
Some believe that an odd number of lands and grooves is more accurate with an open based FMJ bullet. The theory being that the bullet is not squeezed as much between two lands, so less lead is pushed out of the base of the bullet affecting the accuracy. The number of grooves and depth of grooves can also affect drag, blow-by, and tendency to foul.
I read a post in another forum that stated: (paraphrased) The purpose of the rifling is to engage the bullet in order to prevent it from skidding down the barrel and in doing so it deforms the bullet so it fits the rifling tightly enough so that it cannot skid. The more the number of grooves is increased, the more the bullet is deformed as it travels down the barrel. So I think you want enough groves to grip the bullet tightly enough to prevent skidding, but not so much as to overly deform the bullet or cause excessive fouling or blow-by. I would think that 3 groves would be adequate and 5 bit much, but again, I am not an expert.
Basically, what it all boils down to is that this is all theoretical and I think that anyone who can give you a definitive answer, unless a true expert, is likely full of hogwash, but I could be wrong. I really do not know the answer to this question. My advice would be to contact you barrel maker and discuss the matter with him.
Perhaps someone with more experience will give us an explanation.
Last edited by High_Noon; 06/30/16.
l told my pap and mam I was going to be a mountain man; acted like they was gut-shot. Make your life go here. Here's where the peoples is. Mother Gue, I says, the Rocky Mountains is the marrow of the world, and by God, I was right. - Del Gue
