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February 8, 2018, 09:01 AM | #1 |
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6 groove vs. 5 groove Old 6.5cm vs new 6.5cm
6 groove vs. 5 groove Old 6.5cm vs new 6.5cm
I was going over the spec sheets for the Ruger American Predator in 6.5 creedmore, trying to decide should I get the older one with the rotary mag that has a solid reputation for accuracy, or get the newer model with the AI style mag. In the specs, I noticed that the older model has 6 groove rifling and the new model has 5 groove rifling.... Hmmmmmm... What is the difference I thought. So I sent an e-mail to Ruger last week, hoping for an answer to that question, pros and cons to the 6 groove (older) vs. the 5 groove (newer) but alas a week has gone by with no response. So, I am asking you fine people. What if any, are the advantages. I was so ready to pull the trigger on a new Ruger American Predator in 6.5 creedmore but I want to get the potentially better unit. Any thoughts? I don't really care about the magazine. I have a rotary mag in my Ruger American .30-06 and have never had a single issue with it. Speaking of .30-06 Ruger has a new American line in "Go Wild Camo". This .30-06 in the "Go Wild Camo" has a heavier threaded barrel like the predator line and instead of the 6 groove rifling like my "plain ol'" American .30-06, it has the 5 groove rifling. My 6 groove gun is (at least in my opinion) very accurate. Thoughts anyone? |
February 8, 2018, 09:36 AM | #2 |
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Honestly it doesn't matter how many grooves a barrel has. The military has often used two groove barrels, and I have a Pac-nor Super Match that's very accurate and only has three grooves. The last custom barrel I ordered I went with a 1:7 5R twist barrel, I did this because of how well my 5R barrel shot in a cheap T/C Venture rifle.
I think going to the Accuracy International style magazines was a good move by Ruger, but their smartest move was using AR15 magazines for .223 and others. I never had a problem with my American in .300 BLK, but there have been many reports of issues with that cartridge.
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February 8, 2018, 11:37 AM | #3 |
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I had a link to a study on this a while back, but it's lost in my bookmarks somewhere. Basically 5 or 3 grooves requires less force to obturate the bullet than 6 or 4 grooves does, producing less drag in the barrel and consistently higher velocities.
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February 8, 2018, 04:34 PM | #4 |
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I believe the idea is that an odd number of lands is better than even. That way as the bullet is deformed going down the barrel the bullet gets engraved by a land directly opposite where is can flow into a groove.
That would make 5 better than either 4 or 6. I can see the logic. How it would actually relate to a Ruger barrel, I dont believe it matters. Not on a Ruger. Hey, "5 R" sounds cools, right? Why not, how could it hurt? The accuracy will be a based on the quality of the barrel, not the number grooves. If you get into some multi $1000 super duper barrel, sure, the theory sounds reasonable. But for Ruger - no way it will make any measurable difference. I don't believe. Bottom line, dont be afraid of 5 grooves. |
February 8, 2018, 06:53 PM | #5 |
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This is what 5R means
These barrels have 5 grooves, and the lands have angular sides.
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February 9, 2018, 09:14 AM | #6 |
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semi-comparison
FWIW - I have Ruger American 7mm-08 with a 6 groove barrel and a Ruger American Predator 223 with a 5 groove barrel. Shooting the same brand a line of ammo (Federal Fusion), both are very accurate. If I do my part 100%, I can put 3 of 5 shots on a 1" bulls eye at 100 yds wit the other 2 mickey mousing the circumference of the 1".
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February 11, 2018, 09:14 AM | #7 |
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No grooves..
Like polygonal... |
February 13, 2018, 12:11 AM | #8 |
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Thanks for the thoughts and input guys. My son and I have a 5 groove Ruger American Predator in 6.5 Creedmoore on layaway now... Now, to decide what glass to go with. Been looking ar Nikon Black in 6-24X50 or Nikon Prostaff 5 in 4.5-18X40.... I have already decided to go with a Warne steel 20 moa base and Warne Maxima rings.
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February 16, 2018, 10:46 PM | #9 |
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Bought a T/C compass in 6.5 cm, has the 5 r rifling. Most accurate rifle I have.
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February 17, 2018, 08:46 AM | #10 | |
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Quote:
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February 20, 2018, 05:37 AM | #11 |
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It doesn't matter how many grooves you have. 3 to 6 will work the same. On my 6.5cm I've got a 5r. The 5r is supposed to be easier to clean but I can't tell the difference.
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February 20, 2018, 12:15 PM | #12 |
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Its all in the barrel quality not the groves.
A good 4 grove is as good as a good 5R grove, Polygonal or Pentagonal barrel (that has to be next) . All the stuff about forces and bearing and pressure is hype. If you have a quality process you get a quality barrel. Even the two grove barrels were accurate enough.
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February 20, 2018, 12:45 PM | #13 |
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I don't think anyone claimed better accurate, even Boot Obermeyer has never said that and he owned 5R name.
I have 2-30-06 one has Bartlein 5R other has Shilen 4 groove Ratchet twist. http://www.shilen.com/ratchetRifle.html
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February 20, 2018, 04:03 PM | #14 |
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Whats the point of more work and no more accurate?
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February 20, 2018, 06:25 PM | #15 |
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RC20, who you posting to.
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February 20, 2018, 08:15 PM | #16 |
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Old Roper, thought it was obvious
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February 20, 2018, 11:33 PM | #17 |
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RC20, I sure didn't know loading for couple 30-06 was considered work. I really have no idea what your posting about.
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February 28, 2018, 03:54 PM | #18 |
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Okay, Sorry for the delay, but I finally got a reply from Ruger on what was the difference between 5 groove and 6 groove rifling.... Here is their responce:
"Mr. Knapp, We apologize for the delay. These are both product updates for 2018. 5 groove rifling causes less bullet deformation increasing accuracy potential and generally is easier to clean. The AI magazine provides our customers a new option, but both 6973 and 26973 are available to serve all preferences. Thank you for your interest in Ruger. Ruger Customer Service " Thoughts anyone. We ended up getting the newer rifle, by the way and it shoots good. |
February 28, 2018, 05:16 PM | #19 |
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Boots Obermeyer been saying pretty close same thing for years.
http://obermeyerbarrels.com/faq.html Read down to this What does it mean when a barrel is said to be a "5R"?
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