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Mixing brass between Bolt gun and gas gun?

ReaperDriver

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  • Sep 5, 2009
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    Vegas Baby!
    Assuming I FL size the brass before loading to each gun's specific chamber and Headspace - is there any issue with mixing the same brass between two rifles of the same caliber? Or is it better to keep each lot of brass dedicated to each rifle?

    For instance I have a .260 Rem Bolt gun and a new .260 gas gun I just built and am load developing for. I have a FL die dedicated to each rifle set to each rifle's chamber dimensions such that the shoulder is bumped to about .002 less than a fired round IN THAT GUN. I could segregate the brass, but then it becomes a logistical PITA to segregate it at the range and then separate it before it goes into the tumbler, etc.
     
    I separate my 308 between bolt and gas gun. Like you, two sets of dies are setup for each gun. Even after a FL resize, I find they don't fit in opposite chambers.

    Keeping them separate isn't too hard. Gas gun cartridges will have tell tale gouges on the necks from the barrel extension even after tumbling.
     
    Assuming I FL size the brass before loading to each gun's specific chamber and Headspace - is there any issue with mixing the same brass between two rifles of the same caliber? Or is it better to keep each lot of brass dedicated to each rifle?

    For instance I have a .260 Rem Bolt gun and a new .260 gas gun I just built and am load developing for. I have a FL die dedicated to each rifle set to each rifle's chamber dimensions such that the shoulder is bumped to about .002 less than a fired round IN THAT GUN. I could segregate the brass, but then it becomes a logistical PITA to segregate it at the range and then separate it before it goes into the tumbler, etc.
    I’d keep them separate. I reload for a 308 bolt and semi and the bolt gun brass is not as “blown out” at the base relative to the semi owing to very slightly different chamber dimensions. Additionally they have different fired case head to shoulder datum dimensions.

    Mixing them in the past has translated to more variations in the batch of resized cases.
     
    I do not mix mine for one really good reason--Murphy's Law.
    Someday no matter what, at just the wrong time, your shit won't work and you are going to be really pissed.
    Just sayin'.
     
    As long as you don't have illusions of extreme accuracy or brass life, it should work.
    Well, this is the point I'm trying to get at. I'm not just talking about plinking loads. Both guns are intended for LR precision shooting. Are you saying that to get the most accuracy out of the brass in each gun, they need to never pass through the other's chamber?

    If that is the case, I'm more than happy to go through the additional work to segregate them.
     
    Good stuff guys thanks. I have so far been keeping them separate for all the reasons you guys mention, but I didn't have any baseline to compare to. I was just seeing if there really is a difference in performance. So much for being lazy....... ;)
     
    Well, this is the point I'm trying to get at. I'm not just talking about plinking loads. Both guns are intended for LR precision shooting. Are you saying that to get the most accuracy out of the brass in each gun, they need to never pass through the other's chamber?

    If that is the case, I'm more than happy to go through the additional work to segregate them.

    You're not setting yourself up for consistency. Consider if there was a 4k headspace difference between each chamber. You take a piece of brass fired from the short chamber, and resize it. The shoulder wouldn't bump, and it would have a different capacity to a piece of brass that was fired in the longer chamber then resized with the 2k bump you think you're getting.

    Now fire that short piece in the longer chamber. It's gotta grow 4k to seal. Now, since you're not segregating, say it gets resized back down to the smaller chamber, bumped back 6k from it's second firing. Quite a bit of brass working, ja?
     
    You're not setting yourself up for consistency. Consider if there was a 4k headspace difference between each chamber. You take a piece of brass fired from the short chamber, and resize it. The shoulder wouldn't bump, and it would have a different capacity to a piece of brass that was fired in the longer chamber then resized with the 2k bump you think you're getting.

    Now fire that short piece in the longer chamber. It's gotta grow 4k to seal. Now, since you're not segregating, say it gets resized back down to the smaller chamber, bumped back 6k from it's second firing. Quite a bit of brass working, ja?
    Ja.
     
    You may also consider using a different sizing for each rifle so that you’re not constantly having to readjust your die. I’ve have different sizing dies for each rifle and its a quick exercise to swap them in and out of the COAX when working through brass for each rifle. Plus if one die happens to brake you can just use the other in a pinch.

    I use one Forster micrometer seater for each cartridge as its quick to adjust based on differing loads (ie 308 or 6.5 etc).
     
    You may also consider using a different sizing for each rifle so that you’re not constantly having to readjust your die. I’ve have different sizing dies for each rifle and its a quick exercise to swap them in and out of the COAX when working through brass for each rifle. Plus if one die happens to brake you can just use the other in a pinch.

    I use one Forster micrometer seater for each cartridge as its quick to adjust based on differing loads (ie 308 or 6.5 etc).
    Yep, go back and read the OP. I have a separate sizer die set up for each rifle so I don't have to adjust each time.
     
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    Yep, go back and read the OP. I have a separate sizer die set up for each rifle so I don't have to adjust each time.

    Doesn't matter ..... If your gas gun stretches the brass significantly each firing and you smash it down to fit in either your bolt gun or gas gun, your brass life will be measurably less end of story. I would measure how much the shoulder moves after being fired in your gas gun to get a feel for how much work that brass will see each reloading. If it's seeing. 005-.010 your going to run into big issues.

    If your running a normal load and not hot rodding it, it's not uncommon to get 15-20 firings or more on 308 brass in bolt gun.

    I usually toss my gas gun brass after 5-6 reloadings with my load recipe as that's when signs of case head seperations will start appearing
     
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    The issue I would think would come up is if one gun fires and stretches the case longer than the other and you size it to fit the smaller of the two rifles your overworking the brass more than needed

    Likewise if you fl size the shorter case in the longer setup die the case will stretch a bit but likely not be on par with the longer case sized in the longer die. If that makes sense. Resulting in one round bumped back .002” at the shoulder and the next being bumped .004”

    I could see this resulting in overworked brass and possible case head separation issues from brass flow after firing the shorter shouldered case in the longer chamber if the shoulders aren’t close enough in spec to each other. Likewise overworking the longer case to fit in the shorter chamber

    Maybe both are close enough that it doesn’t matter....??????

    Tuning in to learn as this is all a guess
     
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    One brass batch per gun.... I have 2 .308 bolt guns, one a light build for hunting and one heavy barrel target gun. They don’t share brass. Same thing for my pistols. Could I, yes, but every flier would be the brass’s fault, not my shitty form. My ocd must confirm that I suck at shooting, so I can get better. I like the only factor of my crappy groups to be me, not a component. If you have not guessed, I can justify anything.
     
    Easiest way to keep separate brass batches is to use different headstamps - example - Lapua for bolt gun, something cheaper for gas gun. Then you can easily tell difference even after tumbling or other bulk procedures where all brass is mixed.
     
    I use Lapua for my Comp bolt gun, and Hornady for my Comp gas gun. I refuse to use Lapua in my gas guns because they beat the shit out of brass, and you'll lose way more brass from a self shucker.
     
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    I use Lapua for my Comp bolt gun, and Hornady for my Comp gas gun. I refuse to use Lapua in my gas guns because they beat the shit out of brass, and you'll lose way more brass from a self shucker.
    My thoughts exactly! Run separate brands of brass so I's easy to sort em after a range trip. I did notice a huge improvement in SD with my gas gun though when I switched from Hornady to ADG brass. It's a lil bit cheaper than Lapua(pre-COVID, not sure if still true), but ADG seems to be a lot better than Hornady. Yes it gets beat up, but that's why I bought 400 of em :)
     
    Your improved SD isn’t due to ADG being a better case. It’s due because ADG is a completely different case. You arrived at your improved SD by pure luck.
     
    Your improved SD isn’t due to ADG being a better case. It’s due because ADG is a completely different case. You arrived at your improved SD by pure luck.
    So you're saying brass consistency has nothing to do with SD? It definitely matters, otherwise you'd see the pros trying out Sellier&Bellot brass to see if they get lucky
     
    I say do it. Saves time and instead of buying 2 buckets, you now only have to buy 1.
     
    Spend some time taking precise headspace measurements of statistically significant samples sizes of your resized cases using your proposed method and you'll see why it isn't a great idea.



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