Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: 260 Rem popping primers on factory ammo

  1. #1
    Join Date
    Dec 2008
    Location
    Decatur, IN
    Posts
    1,908
    Feedback Score
    89 (97%)

    260 Rem popping primers on factory ammo

    I'm hooked into 260 Remington pretty deep, bought into that caliber before 6.5 came out and I have so much brass AND a ton of factory loaded Gold Metal Match and Hornady ELD-M ammo for it that is why I use it.

    That being said, here's whats going on and I want to kinda run it passed the forum here to make sure I'm going in the right direction of thinking or if I'm WAYYYYYY out in left field.

    Les begin the trouble shooting below shall we.....
    ------------------------


    I purchased a Saturn Barrels 18in 260 Remington barrel with rifle length gas. At first I was having nothing but stove pipe/double feeds. Got an adjustable gas block and a DPMB Dual Extractor Bolt and that solved the issue of that. Damn gun runs at 7 clicks open unsuppressed and 1 click open suppressed on the gas block. I had this issue on all the platforms I've tried this barrel on so I'm pretty sure the barrel is way over gassed hence the adjustable gas block. I started noticing, especially when suppressed, that after about 10-15 rounds, when the rifle really starts to heat up, I'm literally popping every primer on every shot.

    Am I correct in thinking that this chamber is undersized an as the rifle builds up heat is causing massive pressure issues? All I have been shooting is factory loaded ammo that I got pre-insanity pricing via RSR Group and Davidsons, I got a couple thousand rounds of each. This issue happens with both the Federal Gold Medal Match 142gr ammo and Hornady 130gr ELD ammo.

    I need to get a Go/No Go gauge and a chamber reamer. Anyone know where I can find those?

    Just some info on the rifle itself. It is a DB10 that runs 100% with 308 barrel. I have 2 others in 308 that run absolutely amazing (granted, those both have the barrels replaced with Ballistic Advantage barrels and DPMS Dual Extractor Bolts) I've tested this 260 barrel on multiple other AR10 platforms with same results.

  2. #2
    Join Date
    Apr 2007
    Location
    FL
    Posts
    9,300
    Feedback Score
    28 (100%)
    Define "popping primer".
    Jack Leuba
    Director of Sales
    Knight's Armament Company
    jleuba@knightarmco.com

  3. #3
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    29,517
    Feedback Score
    14 (100%)
    You have any chrono data to help dial this in at all?
    "You people have too much time on your hands." - scottryan

  4. #4
    Join Date
    Dec 2008
    Location
    Decatur, IN
    Posts
    1,908
    Feedback Score
    89 (97%)
    Blowing primers completely out of primer pocket. I have not chrono’d any of this ammo, probably should!

    Will say that, while it’s a bolt action, when shooting this ammo thru my Savage 110 Predator in 260 REM, it does not show any pressure signs at all.

  5. #5
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    29,517
    Feedback Score
    14 (100%)
    Quote Originally Posted by jwfuhrman View Post
    Will say that, while it’s a bolt action, when shooting this ammo thru my Savage 110 Predator in 260 REM, it does not show any pressure signs at all.
    Definitely pointing to a chamber or bore issue. Do you have a riflesmith who could pin gauge the bore? That'd be the cheapest and easiest starting point.
    "You people have too much time on your hands." - scottryan

  6. #6
    Join Date
    Dec 2008
    Location
    Decatur, IN
    Posts
    1,908
    Feedback Score
    89 (97%)
    I do indeed. That’s the way I was leaning I just wanted to kinda throw the issue and question out there for you guys. Wanted to make sure I was thinking correctly on what was causing the issue.

    With that said, anyone got barrel recommendations? It’s an 18in barrel and I’m debating on going up to a 20. Still shorter than the 24in on the bolt gun, but longer to get the extra velocity.

    Jack I think I just saw you post in a thread about short 6.5’s and 16 and 18 guns for that were performing wonderfully, but 260 is just different enough that I’m not sure a little longer isn’t better barrel wise.

  7. #7
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    29,517
    Feedback Score
    14 (100%)
    Yeah... with the same ammo being fine in another gun, I'd start with a pin gauge check. If nothing is wrong there, maybe the guy can do a chamber cast or measure your spent brass for something weird??
    "You people have too much time on your hands." - scottryan

  8. #8
    Join Date
    Dec 2008
    Location
    Decatur, IN
    Posts
    1,908
    Feedback Score
    89 (97%)
    Awesome. Glad my train of thought on the whole thing was going in the correct direction.

  9. #9
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    29,517
    Feedback Score
    14 (100%)
    Popped primers are so annoying. I went through a miserable run of those with the CCI 41s I was messing with the last few months.
    "You people have too much time on your hands." - scottryan

  10. #10
    Join Date
    Jul 2006
    Location
    Oregon
    Posts
    3,908
    Feedback Score
    2 (100%)
    I think that “dropped primer” is a better term.

    I have seen it from several calibers in the AR-10. I believe it may be ammo related, as certain lots would see this problem while others would not.

    My theory:
    The AR-10 may not support the cartridge base as much as ideal, allowing the base to expand under pressure. It then may extract too early and eject too violently. So if the brass is a bit softer, or the primer pocket is a bit larger, it all adds up to not hang onto the primer when the case is ejected.

    Some problem with the chamber raising pressure would also increase some of the problems above.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •