I do have a .40S&W to 9mm Lone Wolf conversion barrel for my G35. It's a "drop-in" barrel so no extra cosmetics need to be done, besides picking up a G17 9mm magazine.

When I first shot it at the range, 100 rounds of Winchester White Box 9mm, I had some jams of failure to eject and stove pipes every other shot I took. I contacted JR at Lone Wolf and he said to try +P ammo or a lighter recoil spring (even though the G35 spring is the same as a G34 spring. I think I'm the 1% of having issues with this barrel. But the majority of others enjoy theirs.

I just picked up 250 rounds of Remington UMC 9mm and I'll have to use it up. Maybe the barrel needs to be "broken in".

Here it is:





Go try it out yourself. They are pretty affordable.

I ordered the same barrel for my G31 about two weeks ago. At the moment, they are out of stock... the guy I spoke with said that the barrels sound "be there any day now." I wish they would let you know on their website if an item is out of stock. It would have effected mt decision to order. But too late now. I'll post my comments on the barrel when I finally get it. I'm hoping that it's worth the wait.