I recently got my hands on a Holosun HS407C V2 reflex optical sight which went right on the (optics ready) IWI Masada.
Optics Ready (After a Fashion)
The Masada includes a number of mounting plates and fasteners for the major brands and models of optical sights, and while Holosun isn’t explicitly listed as a compatible make, the RMR mounting plate fits (almost) perfectly.
And there’s that little patent lawsuit, but I’m not commenting on that.
Apparently there is a slight dimensional discrepancy between the Holosun sights and the Trijicon RMR, so the screws included with the Masada for the RMR would got a shade too deep (and prevent the pistol from entering battery). However, as an Amazon reviewer points out, the shorter fasteners for the Sig Zero sights would work.
Zeroing It In
There’s a gazillion blog posts, videos, and tutorials on calibrating that red dot, and they all propose the lather-rinse-repeat process of incrementally getting on-target. Which means a trip to the range, and I won’t argue with that!
Lather, Rinse, Repeat
The process turned out to be the following: set up the target at 10 yards, take 3 shots at that distance, bring the target back, make adjustments on the sight, do it again, at some point switch to a different target on the sheet.
Going from the lower right to the middle circles, then flipping the sheet around, I was getting the hang of shooting with the optic as well as “dialing in” the point of impact to the point of aim.
And then, a 10 yard run-through:
Given that I was firing from an unsupported two-handed stance, I figured this was close enough without using more ammo. I’ll be the first to admit that this isn’t a terribly precise calibration, but I’m playing (around) with what I got.
Some Snags Along the Way
Remember what I said earlier about the Holosun optic being a tad thinner than the Trijicon RMR? It turns out that using the shortest screws isn’t enough to prevent failures to enter battery! After a heckin' concern as to why the pistol wouldn’t chamber properly, I figured out the cause. After about 50 rounds, the slight bit of the excess bits seemed to abrade themselves out, so everything was back to normal.
Close Enough for Hand Grenades (And Red Dots?)
Here’s 15 rounds at 10 yards:
10 shots at 50 feet:
15 rounds of Speer Gold Dot JHP at 7 yards:
As exaggerated by less-than-stellar marksmanship, we see that points of impact at closer distances than the “zero” range are lower than points of aim, and the reverse occurs when going beyond the “zero” distance of 10 yards.
Iterate Through to the Other Side
I’ve got a pistol rest on order, so I intend to return to the range with it to do some fine(r) tuning of the sight. I may re-zero the Holosun to 15 yards instead of 10, but we’ll see how this turns out. I’ll also be keeping an eye on the Masada to see if the failure to enter battery issue continues.