I have two of them. Bought them about 6 weeks ago. One for my Glock 23 and the other for my XD.40sc. Upon receipt, cleaned them and went to an indoor range and they performed good. Took them to an outdoor range with my brother who is an AVID shooter and we had two FTE's. May have been ammo, not sure, but on the companies package it says may need a little polishing. My brother polished the area as directed and we went back and shot them and both performed flawlessly.
Yesterday went to the range and shot shoot 100rds. thru each and had 2 FTF's and 1 FTE. Not barrel or gun problems but cheap Tulow ammo. Two shells had primer hits but NO bang and the FTE not sure what may have caused it.
I got these for the following reasons: First on the Glock you don't have to buy 9mm mags. it works with your existing .40 mags. You do need 9mm mags. for the XD as the round "jams" if you try the .40 XD mag.
Second it came to cost of the rounds. Being retired money is tight and I figure over the my shooting life I can shoot more 9mm at about .22 cents around than .40 at about .35 cents around.
The company does not always respond well to after-the-sale questions, so be-aware.
Hope this helps
I would never question first hand experinece, but let me say that it is common knowlage that .40 Sigs use different height sights then .357 and 9mm in the same gun. Recoil related. I had a P239 .40 that I bought a Sig .357 barrel for, and it shot very low with the 6/8 .40 sights. 9mm and .357 are spec'd with 8/8 hight sights and .40 and .45 with 6/8. You can't blame high/low on the barrel unless it's tuned to the sights.
That sounds like more than I know about them. In use, the .357 Sig barrel from Sig is spot on at 15 yards. The EKF shoots 4 inches low. If I intended to make the change permanent then I might have adjusted the sights and I am sure it would have been fine. I did not have any FTE's, it worked smoothly. The drop may be attributed to the compensation on the barrel, since the Sig barrel did not have it.