9MM XDM barrel upgrade and ? for Jerry

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9MM XDM barrel upgrade and ? for Jerry

Post by dronning on Tue Jun 28, 2016 2:31 am

The 5.25 9MM stock barrel is a very fast 1-10 twist.  Mine has a pretty tight fit, but could be improved.  I haven't been able to machine rest it, but I doubt it will hold the 10 ring.
Bar-Sto (1-16 twist) says their gunsmith fit barrel will give you 2 1/2" groups at 50 yards, the drop in barrel is 3 1/2".

Jerry,
Given some of the work you have done with fast twist barrels would it be worth the effort to have the stock barrel welded and fit verses replacing with the Bar-Sto?


I'm thinking the 1-10 twist might give better accuracy with lighter loads??

- Dave
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Re: 9MM XDM barrel upgrade and ? for Jerry

Post by Jerry Keefer on Tue Jun 28, 2016 1:08 pm

Light loads with lead will benefit greatly from the fast twist.. That being said, my conversations, or perhaps collaborations with some of the most knowledgeable in the game, ask, " How can you  over stabilize a bullet "??.. If you notice, the 32 twist crowd is cranking some high FPS to get the stabilization. The 9mm is very close to the 38 spl projectile in weight diameter, etc.. The 38 excels at slow speed, high rpms.. So the 9mm is going to act as a near mirror to the 38..
I am not a big fan of welding on barrels.. I have been very successful doing so.. I have also seen cracks appear.. In the days of Oxy/Acet, cracks were more common than not.  Today pulse tig is a much better, and more forgiving method..
pre heat and post heat with numerous copper heat sinks help  a great deal. Not all barrel metal is the same.. The Douglas barrel blanks I am machining now, is some rather tough material, which eats up HS tooling...

Done.. This KKM barrel went on to win numerous championships and set a fair number of records .. But I avoid welding on barrels..SmileSmile
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Re: 9MM XDM barrel upgrade and ? for Jerry

Post by JIMPGOV on Tue Jun 28, 2016 2:26 pm

WITH THAT 1-10 TWIST YOU WOULD DO WELL USING 147GR BULLETS. THE HORNADY 147 XTP IS A BOAT TAIL BULLET. IT HAS EXCELLENT ACCURACY AT 50YDS WITH THAT TWIST. OAL 1.142" 4.2 GR VV330 OR 4.0 GR WSF. THE ORIGINAL S&W PPC9'S WERE CLOSE TO THAT TWIST (1-11.5" IF I REMEMBER CORRECTLY)AND WERE AWESOME AT 50 YDS WITH THOSE LOADS. REAL SOFT SHOOTING. JIM P

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Re: 9MM XDM barrel upgrade and ? for Jerry

Post by dronning on Tue Jun 28, 2016 4:21 pm

Jerry, Thanks, I'll stay away from welding the barrel 

Jim Thanks for the load data, I have some Hornady 147gr XTP & 147gr FMJ RN bullets.  I'll give both a try with that load data.  

I need to tighten the group at 50 yards for the P100 run with the XDM.  Headed down to the loading room, then off to the range!

- Dave
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