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Discussion Starter · #1 ·
This weekend I got the magnifier swapped out on my primary AR; from the Vortex VMX-3T to the Trijicon Micro. Also went ahead and re-zeroed the rifle from its old 25/350 (really more like 25/370 if my calculations are correct) to a more-realistic (for my eyesight) 50/250 zero. I considered the 36/300 zero, which is better for longer ranges, but decided to go with the 50-yard instead. The 36-yard zero keeps things within about a 5-5½” deviation from point-of-aim all the way out to 300 or so yards. But it does it by being around 3¾ inch high at 150 yards to 1¾ inch low at 300. For my purposes, the chance of me needing to shoot that gun at 300+ yards is pretty nil. With the 50-yard zero, you reduce the mpbr distance to 250 instead of 300, but I can totally live with that for this gun.

The upside of using the 50/250 zero so is that not only does it shrink that variance from 5½ inches to 4½, but it evens it out a bunch as well; with the highest point of the arc being roughly 2¼” at 150 yards and the lowest being around 2½ at 250 yards. So from muzzle to 250 yards, bullet path is never more than 2.5” from point of aim. Obviously, this is based on certain variables of bullet weight, barrel length, etc. This is based on M193 from a 16” barrel.

On the magnifier change, the micro is definitely a LOT smaller and lighter. It still (just barely) lets me keep the backup folding rear sight in place as well. The optical quality is definitely better than the older Vortex, but that’s as it should be at the price point. The 5-6 oz of weight reduction is more noticeable than I expected, but that’s a good thing. Overall, very happy with it.

One issue that I held out faint hope for was that the new magnifier might reduce the ‘slash’ effect of the MRO’s reticle when magnified. But when magnified thru the Trijicon magnifier the dot looks just as it does thru the Vortex magnifier; more of a slash than a dot.

It’s a known & common issue - while MRO’s are great red dots, they do have a tendency for the dot to become more of a slash or dash when magnified, and mine are no exception. Un-magnified, it looks okay even with my minor astigmatism, but when magnified it becomes more of a slash than a circle. Basically it looks like a tiny red comet with the bright head at 10 o’clock, and the fading tail at 4 o’clock. It’s a fairly long comet shape, running about 10-12 MOA from head to tail. Also have to remember that the head (the brightest point) is the actual aiming point; you don’t center the slash on the target, you use the bright spot as your aiming point or it will hit left. Don’t really like that, but it is what it is, and I’m not going to start from scratch over it. The new MRO HD supposedly addresses the problem, but I’m not going to spend that kind of money for a better dot, especially when the new HD version has much-reduced battery life as well. It’s only an issue when magnified, and the odds of me needing the magnifier in a high-stress situation is (again) pretty nil. I briefly considered re-zeroing the MRO to make the center of the ‘slash’ the aiming point, but fortunately came to my senses before doing so. Because doing so would have dinked up the non-magnified aiming point, and non-magnified is how this gun gets 95%+ of its use. But as little as I shoot the gun with magnifier in place, things can stay just as they are at this point. The magnifier doesn’t even stay on the gun normally. It’s on a QD mount, and sits next to the gun in the rack so it can be grabbed easily if desired.

Fwiw, I did try the magnifier on another gun’s MRO, and same exact thing; same size, shape, and direction of the slash effect. I didn’t take any pics; if I think of it tonight I will.
 

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Discussion Starter · #2 ·
...The 36-yard zero keeps things within about a 5-5½” deviation from point-of-aim all the way out to 300 or so yards. But it does it by being around 3¾ inch high at 150 yards to 1¾ inch low at 300. For my purposes, the chance of me needing to shoot that gun at 300+ yards is pretty nil. With the 50-yard zero, you reduce the mpbr distance to 250 instead of 300, but I can totally live with that for this gun.

The upside of using the 50/250 zero so is that not only does it shrink that variance from 5½ inches to 4½, but it evens it out a bunch as well; with the highest point of the arc being roughly 2¼” at 150 yards and the lowest being around 2½ at 250 yards. So from muzzle to 250 yards, bullet path is never more than 2.5” from point of aim.
Fwiw, just saw an error here. It's not a "5 1/2 inch deviation from point of aim" out to 300, it's a total variance (difference between high and low points) of 5.5 inches. Basically, never more than 3 3/4" deviation high, to 1 3/4" deviation low; a total 5.5" spread, with POA being always inside that 5.5" circle.

That was why the change to the 50-yard zero. From muzzle to 250 yards, it keeps the POI within 2.5" (high or low) of POA, keeping POI closer to POA for the entirety of that distance; and it's very rare that I shoot this gun past 150 anyway.
 
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