Just finished install of the Swampfox Sentinel. Looks bad***. One minor thing kind of bothered me. In the manual, they label the three sets of mounting screws that came with the sight: M4 x .07 x 7.5mm screws for Springfield Hellcat, M4 x .07 x 10.1 mm length for Canik, and some M3s for P365. I messed with the 7.5 mm ones they specifically labeled for the Hellcat for 10 min and could not get them to thread. When I look at the sight with waterproof plate and screws in OFF of the gun it looks like the screws only extend past the sight enough to maybe get a 3/4 turn into the holes on the slide, if that. Like I said, I couldn't get them to catch at all. So, I ended up using the 10.1 mm screws. They go down flush with about 4-5 full turns, but I'm still concerned as even the SA website mounting kit comes with the M4 x .07 x 7.5mm screws. BTW
@SkyMarshall I got the Sentinel-M for $250. Looks like the Holosun 407K is only $30 difference FWIW.
Can someone who has successfully installed the Sentinel weigh in here? I won't take it to the range until I confirm. I will also email Swampfox. Anyway, here's some quick pics.