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Extreme 124 HP


TPMINAZ

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The two reloading manuals i have state 1.065" for 124gr HP & 1.075" for 125gr HP...but this won't be much use... PLUNK TEST your barrels...every bullet manufacturer is a little different and the only way to be absolutely sure is to plunk test.

For my VP9, I had one brand of 124gr Round nose pass plunk test at 1.21" and another brand of 124gr RN pass at 1.05"...which decreased my case capacity too much and was giving high pressure at 130PF...

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I should have provided some more info. My issue is with feeding. I have put about 1,000 through the DW PM9 without a single issue.  In the XDM I have had about 5-6 FTF out of around 750 rounds. Right now they are 1.07.  I suspect they may be slightly short but wondered if anyone here has a working profile with this bullet. I have shot tens of thousands of Blue Bullets and Extreme in 124 RN without issues. The OAL is 1.12.   I realize I will need to find the exact sweet spot for my guns but feedback is welcome.

 

They all pass the punk test, cased gauged and are at 132 pf with VV320.

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1 hour ago, TPMINAZ said:

My issue is with feeding.

Oh...that changes the discussion entirely.  I have 0 xp with hollow points...all i know is that feeding them can be finicky...so sorry i'm not much help with "tuning" HP COL...  

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TPMINAZ, so 1.07 passes your plunk test.  Fine.  The question still remains what the maximum OAL is that will pass the plunk test.  That needs to be your starting point.  The chambers of your American-made PM9 and your Croatian-made XDm are going to be cut to different depths, with the PM9 being at the deep end, and the XDm at the shallow end.  I suspect your PM9 will handle those bullets loaded much longer than the XDm -- maybe .04 or more longer than the XDm.  So if you want one load that will work in both, it is going to have to be tailored to the XDm first, then function-tested in the PM9.  

If I were you, I would load a dummy (no primer, no powder) with that bullet to 1.12.  Make sure you taper crimp normally.  Plunk test to verify it won't plunk and spin freely.  Then seat a little deeper, a thousandth or two, and test.  Then a little deeper and test.  Then a little deeper and test.  Then a little deeper and test.  When you start, it likely won't plunk nicely, and won't spin at all.  Then it will produce a little plunk sound but won't spin.  Then it will spin with significant drag.  Then it will spin with lighter and lighter drag until you eventually get it down to an OAL where it spins with no drag.  It will spin absolutely freely.  That's the maximum OAL without rifling engagement.  You should deduct .015 from that max as an initial target OAL.  You don't want to try to load to the absolute max because there will always be some natural variation in OAL from one pull of the press to the next, and if you target the absolute max, you are likely to end up with some longer than what you're targeting, and you'll end up with some cartridges with minor rifling engagement and some not. 

My records show a max OAL of 1.11 in a CZ.  I do not own and have not loaded for an XDm, but I believe they are typically throated about the same or a little shorter than CZ pistols, so you should probably plunk and spin close to 1.11, maybe a little shorter, maybe a little longer.  I suspect 1.12 would be a good guess to start with, then start working down from there.

Good luck. ;) 

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