Just wanting to let everyone know how my new Storm Lakes 40 to 9mm conversion barrel performed at the range today and let me tell you it exceeded all of my expectations... It's a noticeably tighter fit than the stock barrel but cycles so smooth like it was there from factory. I used Kci glock 17 mags i picked up on sale for 15 dollars an they worked just fine. i only had one fail to fire and im blaming that on the cheap russian ammo i ran thru the first couple mags. after i switched to federal ammunition i had absolutely no problems. I've seen some posts where accuracy was an issue with the barrels but i was hitting just as tight of patterns as with the stock barrel. Overall i would recommend this to anyone. Much respect to Storm lakes for makin yet another quality product.