I recently asked Lonewolf Dist. for further info on conversion barrels for .40 to 9mm. Due to 1% of 9mm conversion barrels are affected by the poor performance with WWB and Rem. (UMC) ammo. JR Sheppard of LWD was nice enough to give me a speedy and informative reply. From: TangoFoxtrot Sent: Saturday, February 06, 2010 9:20 AM To: JR Shepard Subject: Conversion Barrels On your web site you have the statement below. I was interested in the purchase of one of these converion barrels. Also when are they due in? Notice: About 1% of our 9mm conversion barrels are affected by the poor performance of Winchester White Box (WWB) and/or Remington (UMC) 115 grain ammunition and may fail to extract reliably. For more information email us direct at firstname.lastname@example.org Lonewolf Distributors Reply: TF Here is the info you requested: 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. FYI: WWB 115 gr ammunition is the weakest sub standard ammunition you can purchase. This ammo is also known to produce failures in all standard Glock 9mm pistols. JR Thank you for your business Lone Wolf Distributors Inc. <http://www.lonewolfdist.com/> Worlds largest selection of Glock accessories 208-437-0612 Office 888-279-2077 Fax Wanna kill these ads? We can help!