Grendel vs Grendel II

Discussion in '6mm, 6.5mm, and .25 Cal (Not 6BR)' started by 257Roberts, Dec 5, 2019.

  1. 257Roberts

    257Roberts

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    Anybody have experience with the Grendel II chamber?
    What is the technical difference between them?
    Is there a performance difference?
    Are different reloading dies required?

    I have long been thinking of putting together a AR15 Grendel Upper and am getting close to pulling the trigger on a barrel.
     
  2. 2506

    2506

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    The real difference between the two is head space. The Grendel I which to my knowledge is no longer made by MOST was designed to work with the bolt face depth used with the 7.62x39. The Grendel II which is the standard SAAMI is set up to use a bolt face that is deeper and supports the case head better. I have two ARs in 6.5 Grendel II. The first one I bought was an 20" upper from Bear Creek Arsenal because it was cheap and I got exactly that a cheap nightmare. Thing shot like a shotgun. I wasted a lot of ammo trying to make it group under 3" at 100 yards. Ended up finding that the crown looked like it had been done on a side grinder. Tried to contact BCA through email a number of times with no results. Seems they do not check their email. Found a phone number to call and was transferred to warranty dept. got voice mail and left my info. A week later had not been called so called again and got voice mail. Called back to person that transferred me and told her story of no call back. She gave excuse that warranty person had been out with flu. She said that the person was in the factory and would call me. A few days latter I got a call and was emailed a shipping label and I had to pack up the upper and send it to them. In 10 days it came back. Barrel looked better but it took about 100 rounds through it to get it to shoot consistent groups with my handloads. It HATED Hornady 123 SST ammo and any hand load with the bullet. It is picky about what it wants to shoot but with handloads I have it shoot consistently under 1" at 100 yards. You can read about many people having this same problem with BCA on the Grendel web site. While I was having all this trouble getting through to BCA I decided to just go whole hog and build me a rifle from scratch. I went with an Oden Works 18" barrel combo package. It was a tack driver from the get go but it also does not care for the Hornady 123 SST ammo nor the bullet itself in hand loads. Both rifles love the 120 Sierra Pro Hunter and Speer Gold Dot. I really like the Grendel for White Tail deer for under 300 yards. I killed one last year with the 20" and the 120 Gold Dot at 111 yards. Bang Flop. Am using the 18" this season with 120 Sierra Pro Hunter in the woods of east TN but have not shot anything with it yet but I still have a month to hunt. Good luck with your build. Go to the 6.5 Grendel web site and you will learn a lot.
     
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  3. Sniper338

    Sniper338

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    Ive had a phenomenal experience with my 20 inch barrel from Saturn custom machine, however it is a cut rifling custom made barrel, not a button rifling cheaper end barrel they make.

    It is well worth getting a barrel made with a good blank imo. I found it to be very finicky to load for, but once I found the load it hammers.
     
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  4. 3Ackleys

    3Ackleys

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    Type I has a .125" bolt face depth and type II is .136" bolt face depth. As stated above most mfg. are using the .136"
    If you buy your barrel and bolt together from the same manufacturer the headspace should be correct.
    The performance is the same- they use the same case.
    The type I with the shallower bolt face is reportedly not as strong of a bolt.
    Dies are the same.

    And if you like here is some light reading on the history:
    http://www.65grendel.com/forum/showthread.php?7420-The-Story-of-the-Grendel-bolt
     
    Last edited: Dec 6, 2019
  5. Sandstorm

    Sandstorm Silver $$ Contributor

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    I like my 20 inch Xcaliber barrel'd build pushing 27.5 grains Tac or 8208Xbr & 123gr Scenars.
    It absolutely Hammer's dime size groups at a 100. Really fun easy to load for cartridge IMHO
     
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  6. Tommie

    Tommie Gold $$ Contributor

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    Are any of the rifle manufacturers stamping their barrels 6.5 Grendel II ? Until this moment I’d never heard of the Grendel II.
     
  7. gunsandgunsmithing

    gunsandgunsmithing The best tuners and wind flags on the market Gold $$ Contributor

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    There's only one Grendel but there were/are two bolts.
    The cartridge did not change in any aspect.
     
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  8. louielouie

    louielouie

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    Over on the 65Grendel forum they've been using the 'Mk136' designation which is 0.136" depth of the bolt face. They sell some group buy 5R barrels with matching bolt heads.
    Of course if you read https://ar15performance.com/faqs about 3/4's down there is a dissenting opinion about 0.125 vs 0.136 bolt depth...
     
  9. jamesh

    jamesh Gold $$ Contributor

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    Interesting read. I have been wondering how removing metal from the bolt could make it stronger.
     
  10. Toddmack

    Toddmack

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    Louie, can you please go post this over on AR15.com??
    If you're a member over at the funny pages you won't, but I had to ask.
     
  11. louielouie

    louielouie

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    I *am* a member but I've seen enough references to certain 'heretics' that I'm not gonna post this and get excommunicated :rolleyes:

    Just trying to keep an open mind - maybe Bloomerg *could* be a good president? o_O
     
  12. Bogusname

    Bogusname Gold $$ Contributor

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    .264 LBC eliminates the issue. Headspace is the same with all. Why in the hell the first Grendel reamer had such a short throat... I don’t know or care. It’s not really an issue to figure out if you chamber them. It’ll just cost you a reamer to have it reground.
    The bolt face depth doesn’t matter if it comes with the barrel. If it was chambered with the shorter or longer bolt face, the headspace was set with that bolt. You should know enough to get the right bolt if you feel you need to swap bolts.
     
    Last edited: Dec 10, 2019
  13. ebb

    ebb

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    Bogusname I clicked on the link at the end of your post and all hell broke out and it tried to lock up my computer, THANKS
     
  14. Bogusname

    Bogusname Gold $$ Contributor

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    I didn’t post a link. I apologize if something happened.
     
  15. ebb

    ebb

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  16. Bogusname

    Bogusname Gold $$ Contributor

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    I can’t see that on my posts. I will delete. I started a site three years ago. I messed with it for about a week and let it go and forgot about it.
     
  17. Bogusname

    Bogusname Gold $$ Contributor

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    It should be gone now. Let me know if you can still see it. I apologize again.
     
  18. ebb

    ebb

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    I thought it was your business and wanted to look. Who ever it belongs to has been hacked.
     

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