4 or 6 groove?

Discussion in 'Gun Project Questions & Gunsmithing' started by Paddyd, Aug 23, 2019.

  1. Paddyd

    Paddyd

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    Thinking of ordering a new 308 barrel. Maker doesn't offer 5R rifling, only 4 or 6 groove. So, which is the better choice and why?
     
  2. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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    If its button rifling i like the 6. If its cut i like the 4. Dont like the 5 either way
     
  3. butchlambert

    butchlambert Site $$ Sponsor

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    Amount of lands and grooves doesn't make a good barrel. Just buy what is offered by a reputable manufacturer.
     
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  4. Paddyd

    Paddyd

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    I ask because they offer both 4 or 6. Since they manufacture with both I figure there must be a reason why someone would do so and wonder what advantage 6 groove might offer over a 4 and whether it would only be advantageous under a certain set of circumstances or across the board
     
  5. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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    No. If you get a barrel from a good mfr it wont matter- youll never see the difference
     
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  6. ngb1787

    ngb1787 Silver $$ Contributor

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    Kreiger told me doesnt matter. Never know the difference.
     
  7. Paddyd

    Paddyd

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    Well I know my shooting skills aren't good enough to differentiate between the two, but I still want to know WHY they bother to manufacture a 6 groove barrel IF there is no benefit. To me there must be some reason for the 6 vs 4 or why would they go to the added expense to tool up for it?
     
  8. SBS

    SBS Gold $$ Contributor

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    I suspect the answer is because enough people prefer one over the other to create sufficient demand -- whether there is sufficient evidence to prove it or not. For years, ammunition makers put a belt on all new magnum calibers when it was not necessary (newer magnum cases had enough shoulder, unlike the .300 and .375 H&H). However the public was convinced a belt was necessary for magnum calibers and the manufacturers obliged them for many years.
     
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  9. swd

    swd Gold $$ Contributor

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    People have preferences and it keeps a sale within that manufacture.
     
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  10. hpshooter

    hpshooter Gold $$ Contributor

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    "wonder what advantage 6 groove might offer over a 4 and whether it would only be advantageous under a certain set of circumstances or across the board"

    It has been awhile so hopefully I have remembered this correctly.

    Years back when service rifle competition was exclusively a .30 caliber game the military match bullet was a 173 grain projectile with a relatively thick, hard jacket. The alternative bullet was the 168 grain Sierra Match King with a relatively thin, soft jacket.

    Popular belief at the time was the 173's performed best in the 4 groove barrels and the 168's excelled in the 6 grooves. There are MANY others here that have the experience to clarify this info regarding service rifles from the .30 caliber days.

    Stan Taylor and Frank can comment from the manufactures standpoint.
    Have had some excellent shooting O3A3's with wartime production 2 groove barrels. Have seen great shooting 3 groove Pac-Nors and a few stellar Marlin Micro-groove barrels.

    For most of us our ability (as in lack of) to hold hard and read the wind consistently makes it a Ford-Chevy-Chrysler type discussion.
     
  11. 338 dude

    338 dude Silver $$ Contributor

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    Only thing I have heard between a four or five groove would also include six even numbers have opposing lands were odd numbers do not. So odd numbers would not cause as much intrusion on the bullet I imagine it would be more important if you had a fast twist rate and the possibility of bullets coming apart as far as accuracy I don’t know of any differences myself
     
  12. butchlambert

    butchlambert Site $$ Sponsor

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    Chuckle chuckle, I've heard the 12 groove micro groove do best with the slo twist, or was it on the fast twist?
     
  13. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

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    Maybe not a legitimate reason for some----but----a 4-groove barrel, with the lands indexed
    to the 4 chuck jaws might be easier and quicker for some to get indicated in.

    This won't apply to some folks and some won't admit it-----but----I like it when available.

    A. Weldy
     
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  14. Tony1320

    Tony1320

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    Why do you not like 5 grove?
     
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  15. Stan Taylor

    Stan Taylor Gold $$ Contributor

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    Well here you go back in the day we did a ton of four groove for barrels the guys shooting high power if you shoot a lot you can go longer between cleaning I honestly don't think one shoot any better but when I shot 300 wsm in 1000 yd I prefer 4groove easy to clean an didn't clean as often.
     
    Last edited: Aug 26, 2019
  16. Shooter13

    Shooter13 Gold $$ Contributor

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    This is from Frank back in 2008:
    The number of grooves? To me the number of grooves has no real bearing on accuracy or barrel life! Some say if you want hard core accuracy go with conventional rifling vs. a 5R type barrel. Some say the 5R's copper foul less. I say B.S. I've seen 5R copper foul with the best of them. Some say the 5R barrels will seal the bullet better in the bore and you get more velocity out of it. Again I haven't seen this either. Some say the 5R barrels don't leave a burr on the bullet and will drift less in the wind. I haven't seen this either.

    99% of the barrels we make for short range bench shooters are 4 groove conventional rifling.

    Across the course high power shooters seems to be a 50/50 split.

    Long range prone shooters seem to prefer the 5R.

    Long range bench shooters I would say the preference is more towards conventional.

    I've got a conventional 5 groove (not 5R) on my short range bench gun. Wanted to try it! The gun hammers!

    I've shot 5R's and 4 groove in prone matches out to a thousand and even compared both in the same match (two man team) and saw no difference. Our team came in 3rd place in that match. Same chambers, same loads! Both guns we're chambered in 6mm Rem with a custom throat. Shoot mostly Berger 105's and Sierra 107's. Both are 1-8 twist. Velocity difference between the 2 is 30fps. The loads average 3155fps between the two. In the match where we shot both on the same relay at the same time. We didn't use anymore or any less windage on one gun vs. the other.

    To me it is more of the quality of the barrel blank. The straighter, the more uniform your bore sizes and the more uniform the twist the more forgiving it is going to be.

    Hope this helps!

    Frank @ Bartlein
     
  17. Ccrider

    Ccrider Gold $$ Contributor

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    @Shooter13 that was 11 years ago. I wonder if Frank’s opinions have changed.
     
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  18. Shooter13

    Shooter13 Gold $$ Contributor

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    Just ask him, hes on here!!
     
  19. butchlambert

    butchlambert Site $$ Sponsor

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    I bet it hasn't!
     
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  20. Shooter13

    Shooter13 Gold $$ Contributor

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    I agree!
     

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