40 cal to 9mm [Archive] - Glock Talk

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pdog
07-02-2010, 20:39
I have a G35 and want to shoot 9mm 115 grainers in it. Is simply replacing the barrel and mags all you need to do. I saw somewhere here a guy was having ejection problems and was told to try 124 grainers. I have a ton of 115 I want to shoot up.

JR
07-04-2010, 20:13
About 1% of our conversion barrels are affected by the poor performance of Winchester White Box (WWB) 115 grain ammunition. This rare failure is too low a percentage to make an issue, however it is one we are well aware of. The fix to resolve this issue is quite simple.

1 Clean and lube your slide and barrel.

2 Shoot 1 mag to 1 box of good quality +P or +P+ ammunition through the barrel.

3 Go back to the WWB 115 gr ammunition. If it runs... great! If you experience more failures you will have a couple choices to make.

Fix A Reduce the recoil spring weight to 11 to 13 lbs. Cost is about $25 for stainless steel guide rod and reduced power spring.

Fix B Shoot 124 gr or a better quality 115 gr ammunition exclusively. WWB 115 gr ammunition is no longer a valid option.



What causes this problem? Several issues come into play.

1 The 40 slide and (40 conversion) barrel is thicker than any standard 9mm slide and barrel. This extra thickness equates to more weight. The combined extra weight taps the energy of the "weak" WWB ammunition to its complete demise. It simply lacks in power and fails to reliably eject the spent round.

2 Every once in awhile a Failure To Feed/Failure To Eject (FTF/FTE) is caused by a fit issue. We resolve fit issues by pumping +P or +P+ ammunition through the gun. This hot ammunition provides extra pressure and the pressure will positively align any and all components. Once they are all aligned there is no longer a fit issue. The FTF/FTE is usually resolved.