It is a slight chance you take. I bought a M&P .40 FS and inspected and shot it enough with the .40 barrel to prove to my satisfaction that it was not problematic and probably wouldn't need warranty work. I would think S&W would have the prove the problem was due to a conversion barrel before it voided the warranty. If the problem wasn't barrel related, S&W would still have to fix it.

Before I shot the M&P with the conversion barrel, I thoroughly checked to make sure it fit properly. If the conversion barrel has a problem, KKM will take care of you on the barrel - maybe the pistol if the barrel caused the problem.

I wouldn't hesitate to do it again. Glock will probably have the same policy. S&W wants to sell 2 handguns not 1.

Many on this forum just buy the factory 9mm barrel and have good results. I bought the KKM conversion barrel just to ensure good fit and function and because I have had good results with KKM barrels before.