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Thread: 7mm-08 reloads extraction issue - thoughts please

  1. #1
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    7mm-08 reloads extraction issue - thoughts please

    Loading for a friend, caliber I don't shoot myself.

    Rifle is a Ruger American, low round count. Brass is once fired factory.
    FL sized.

    Ist batch was loaded with 139gn Hdy Interlock over 43.0gn 2208..Very accurate tight groups, no issues.

    2nd batch is 139gn HDY SST over 43.0gn 2208 so same charge, different projectile, same brass, FL sized.

    Shooting the first of these at range today they are just as accurate, no issues chambering. Shot a group of 3 and 3rd case would not extract. No issue with bolt lift, just could not pull it back. Tried again after about 3 min and it extracted easily. I then shot my rifle, we went up and checked/patched the target, came back to 100m mound and went again..same thing happened, 2 cases extracted fine, 3rd jammed tight, came free after a few minutes. Left rifle same amount of time, about 20min, shot 3 factory rounds he had, no issue.

    So what is going on?

    43.5gn is.max load. I'm thinking of dropping to 43.2 or 43.0 but there are no other pressure signs. No heavy bolt lift, primers are normal, no extractor mark on head..

    Thoughts please?
    I know a lot but it seems less every day...

  2. #2
    Member Micky Duck's Avatar
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    seems weird its the third round both times and lets go later..so heat is part of equasion...POSSIBLY the necks are slightly long?? give chamber a good clean and try again perhaps???have you any interlocts to reload and retry..that rules out any other issue and puts issue cleanly on the SST... maybe they are harder jacket so have bumped pressure up.stranger things have happened.....did you set your overall length by using the earlier interloct to set up seating die or not??? could be skinnier front end olglive so if kept all the same the base of projectile may well be deeper into case giving higher pressure...
    Jhon likes this.
    75/15/10 black powder matters

  3. #3
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    I found decent accuracy at 42.2-42.5gr 2208 with the 139gr sst.
    Isn't abit of crap under the ejector claw which is preventing extraction. Had this happen with a tikka years ago
    veitnamcam, Micky Duck and Jhon like this.
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  4. #4
    Almost literate. veitnamcam's Avatar
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    Unlikely to be a pressure issue if bolt lift is fine.
    Strip and clean bolt check condition and function of extractor.
    Jhon likes this.
    "Hunting and fishing" fucking over licenced firearms owners since ages ago.

    308Win One chambering to rule them all.

  5. #5
    Almost literate. veitnamcam's Avatar
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    Interlock and sst are the same bullet but one with a plastic tip.
    Micky Duck likes this.
    "Hunting and fishing" fucking over licenced firearms owners since ages ago.

    308Win One chambering to rule them all.

  6. #6
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    If it happens again, try pushing it out with a cleaning rod, just to see how much resistance there is.
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    Polish the chamber...
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  8. #8
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    Where did you get your data from? Adi site says 42.2gr as max load and hornady says 41.5gr max load

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    Quote Originally Posted by Trav-6mmrem View Post
    Where did you get your data from? Adi site says 42.2gr as max load and hornady says 41.5gr max load
    Scratch that, I was looking at 140gr load data not 139gr
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  10. #10
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    Quote Originally Posted by Micky Duck View Post
    seems weird its the third round both times and lets go later..so heat is part of equasion...POSSIBLY the necks are slightly long?? give chamber a good clean and try again perhaps???have you any interlocts to reload and retry..that rules out any other issue and puts issue cleanly on the SST... maybe they are harder jacket so have bumped pressure up.stranger things have happened.....did you set your overall length by using the earlier interloct to set up seating die or not??? could be skinnier front end olglive so if kept all the same the base of projectile may well be deeper into case giving higher pressure...
    Thanks Micky, yeah all brass carefully length gauged after FL resizing. Teaching the guy reloading and he did the majority of these under my watchful eye so I'm confident none were missed or incorrect. Flash holes were uniformed, primer pockets cleaned etc etc, the whole enchilada. I do often use a previous round to set the die seating depth but pretty sure this time was set with caliper to Hornady C.O.L. spec. Its the same as the SP at 2.755 but I will check that. There were no issues with chambering the rounds.

    The recurrence of the issue on the 3rd firing makes me suspect a bolt or chamber issue with heat. But its quite bizarre really. Need some more leisurely range time. Also a deep clean of bolt

    Anyway some things to think about and delve deeper on
    I know a lot but it seems less every day...

  11. #11
    Member Micky Duck's Avatar
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    Hmmmm seated to same overall length as soft point MIGHT suggest it's maybe a mm deeper in the case.
    75/15/10 black powder matters

  12. #12
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    Quote Originally Posted by Micky Duck View Post
    Hmmmm seated to same overall length as soft point MIGHT suggest it's maybe a mm deeper in the case.
    Yup, will do some .2gn incremental decreases. But having said that, the current load is below max and the max load is for that C.O.L.
    I know a lot but it seems less every day...

  13. #13
    Almost literate. veitnamcam's Avatar
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    A quick Google of Ruger American extractor issues brings up plenty of results....seems a common issue with the rifle.
    Jhon likes this.
    "Hunting and fishing" fucking over licenced firearms owners since ages ago.

    308Win One chambering to rule them all.

  14. #14
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    Greetings,
    The SST is a different projectile to the Interlock, Although jacket thickness may be similar the SST is significantly longer. This will push up pressure a little if the projectiles are loaded to the same LOA as the longer projectile takes up some powder space.
    I don't think this is the problem however. The fact that the bolt handle can be lifted easily but no pulled back tells me there is no primary extraction. Lifting the bolt handle should cam the case out of the chamber slightly so that the bolt can be pulled back easily. Clearly this is not happening. Whether this is a fault of the particular rifle or is inherent in the design I don't know.
    I used 42.5 grains with the 140 grain Remington CL in a 19 inch barrelled 7mm-08 which produced 2,700 fps.
    Regards Grandpamac.
    PS. I see, as suspected, that the Ruger American is a three lug design. The shorter bolt lift makes it more difficult to produce primary extraction especially in a rifle that sells to a budget price. Dropping the load slightly should help. It would be interesting to know what the two projectile chronographed with the same load.
    Last edited by grandpamac; 30-07-2024 at 09:01 AM.
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  15. #15
    Member sneeze's Avatar
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    @Jhon couple of things, when you say no problem with the bolt lift, was it smooth all the way to the top or was there some resistance toward the end of the lift giving a small click?
    And assuming you still have the offending cases , if you chamber them again in their current fired state do they give the same resistance on extraction? if they do color them with black felt tip chamber and see where the binding is, this issue normally shows just in front of the web.
    SPEARONZ likes this.
    "You'll never find a rainbow if you're looking down" Charlie Chaplin

 

 

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