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9mm Bullet Seating Problem

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  • 9mm Bullet Seating Problem

    I have reloaded .223 for many years, so am familiar with the process. I have just started to reload 9mm Luger for a friend. I have the dies set up (RCBS carbide three die set). I am loading brass he has recovered from his shooting range. FC brass is the most numerous, so I started with that and had no problems at all. I am seating 147 gr. Hornady XTP bullets for an OAL of 1.10, which I believe is the standard for 9mm., using 4.1 gr of Power Pistol. Next, I started loading a few WIN brass and ran into a problem I can't solve without readjusting the seating die. The bullets seat way deeper in the WIN brass. Deep enough that the bullet tip is being damaged and the cases are getting some deformity. Obviously I am not attempting to shoot these rounds. My best guess is that the load is being compressed and thus causing the damage. The bullets are the same length, using calipers, and so is the brass of the two brands. Any help as to why this is happening would be greatly appreciated.

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  • #2
    Compare the difference between FC cases and Win cases. That might be why you are having problems.
    The win case probably longer than FC which causes them to start the taper crimp process sooner than FC cases.
    If that is so you are going to have to adjust dies to work with the Win cases and then adjust when you switch back to FC cases.
    Unless you trim the Win cases to same length as FC cases.
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    • #3
      First off, seat 147's out to 1.165"
      ​Max for 9x19 is 1.169, not 1.10"

      Second, trimming is not needed. Taper crimping is capable of absorbing a LOT of length variation without trouble.


      • #4
        I normally use the bullet manufacturer's suggestions for OAL for a specific bullet. My Hornady manual is out in the shop and I'l too lazy to get up and go get it... Also pistol cases' walls are tapered in the ID and perhaps the Winchester brass is thicker at the bullet's base when seated, making it a tighter, more difficult fit?
        Last edited by mikld; 1 week ago.
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        • #5
          The Winnie's probably have a higher base web inside, never compared all mine. 1.1 is too deep with long 147's, fine with 110 & 125's


          • #6
            Smoke Eater - By any chance, have you checked the case capacity and compared the two? Weighed a couple and compared them that way?
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            • #7
              the 1.1 oal is correct for the 147gr XTP. [for the 147gr Horn. RN it is much too short]

              what happens is you set your dies up for one brand of brass, then you switch and you find out that brand B has more/less internal case taper or brand C has thicker/thinner case walls.
              now is a good time to measure and note the differences between the cases you have.
              look inside them, the web sits higher in some too, some even have bullet stops built into the case for a certain bullet weight.
              the 9mm is easy to load, just nobody can agree on how to do it at the factory.


              • #8
                Thank you all for your suggestions. Case length- same. Case thickness - same at top of case. Case weight - Win 61.5, FC 57.6. Case capacity (using Power Pistol) - Win 9.7 gr., FC 10.1 gr.

                Will try to seat bullet in Win case a little higher and see how that works.


                • #9
                  I use a couple different approaches that have completely eliminated the issue, problem is most hand loaders aren't willing to invest the time or effort, after all it's just 9mm and not a bug hole bottle neck rifle cartridge.

                  First of all, I trim my brass, by doing so I can blaze through the seating taper crimp process without a single hiccup. But when I'm not in the mood to trim or if I'm using brass that was trimmed during a previous loading session, I'll just chamfer the inside of the mouths then seat without taper crimping. If the mouths are chamfered real a good, this works amazingly well with jacketed bullets. The heel will sit up nice and straight in the chamfer and will slide straight into the mouth, no taper crimp necessary. Another benefit is that neck tension is at it's maximum potential using the no taper crimp process, and it takes the inconsistencies associated with taper crimping completely out of the equation, especially when using a bunch of mixed head stamps with varying wall thickness and lengths.

                  Edit to add, loading those 147 gr. XTP's that have the boat tail is a snap with the above process.

                  Last edited by HighBC; 1 week ago. Reason: Seating 147 gr. XTP's without taper crimping


                  • #10
                    Ok,, now that I am home, some measurements.

                    Random Winchester case from my stores:
                    Case length: 0.744 inches.
                    Case DEPTH inside: 0.574 inches.
                    That is a head thickness of 0.170 inches.
                    Fill case with 4.1gr of Power Pistol, it leaves 0.276 inches of available brass above it.

                    Power Pistol is a spherical powder which does not have much ability to be 'packed down'.

                    Hornady 147gr XTP: from a scale-size poster,, approximately .656 inches long overall.
                    My best judgement of the amount of straight bullet shank: 0.456 inches.

                    Inside a .744" case, to create a 1.10" OAL from a .656" bullet, you have to have 0.356" of bullet outside of the case.

                    In order to have .356" of a Hornady 147gr XTP outside the case, you have to put .300" of bullet inside the case.

                    The powder charge only leaves you 0.27+ inches of room to shove .300 inches of bullet.

                    the bullet tip is being damaged and the cases are getting some deformity. Obviously I am not attempting to shoot these rounds. My best guess is that the load is being compressed and thus causing the damage.
                    IMO your "best guess" is correct.

                    Federal case, 0.747 inches long, a mere 3 thousandths longer.
                    Case depth inside:0.583 inches, 10-thousandths deeper than the Winchester (but a longer case).
                    That is a head thickness of 0.164 inches, 6 thousandths thinner than the Winchester.

                    Lengthen the OAL to AT LEAST 1.130", more will do not harm IF it chambers properly without jamming into the rifling.

                    Hornady did NOT develop that load data with Winchester brass, they developed it with Hornady/Frontier brass, which is probably roomier inside than the Winchester.