For years I ran the Burris Fastfire III on my Minis.
I started out preferring the T.V. screen sights like the FastFire over the tube style dots as they seemed to offer better peripheral vision, less of a "tunnel" effect. And the reflex sights like the FF and Venom are much more compact and lighter than a 3 to 8 ounce Tube sight.
The Fastfire on its Picatinny mount out on the Ultimak is low, but just a tad high for my cheek weld. Due to the battery and electronics being under the screen, they will never be as low as tube sight with battery and electronics on the side.
I've been wanting to try the flush knob SLX from Primary Arms for a while. Shake awake, 3.8 ounce tube sight w/ 2 MOA dot.
But I think I did even better with their GLX MD-21s.
It is a 5 ounce sight with Shake Awake (PA calls it Autolive) and a solar panel on top. Supposedly the solar doesn't just kick in when the battery gets low, the sight will run on solar while you are shooting outdoors, so basically the battery is the backup instead of the solar option. Here I turned the carbine so the panel could get the rising sunlight, the first time it had "seen the light".
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But the kicker with this sight is it doesn't have just a 2 or 3 MOA dot, it has the ACSS reticle like some of their scopes and prism sights.
Now instead of a round dot, I can get more precision as I place the sharp tip of the Chevron top on the target.
With the top sighted at 100 yards, the "armpit" of the Chevron is 200, the bottom arms of the Chevron are 250, and the holdover dots are 300, 400, and 450.
I'm talking here about the x39 cartridge for the Mini-30.
The manual comes with the values for about a dozen cartridges, of course these need to be checked with actual range time to "fine tune".
The two buttons on the left side are big and easy to get to.
Press and hold both for a few seconds turns the sight on or off.
![Image]()
A quick press of the + or - button adjusts the brightness, and it can be made very bright. I have no problem in the high desert sun and I keep it turned 3 or 4 steps down from max.
The optic comes with an AR type riser along with a spacer of 3/16" to fine tune the height, and the Picatinny mount.
The sight can be cycled thru various reticle options by holding either button for a few seconds. You can have just a Chevron, just a horseshoe/donut, have both without the holdovers dots below, etc. If I was just target shooting at long range, I'd remove everything but the Chevron. Going into a buiding to check out a noise ? Set it to horseshoe only, no other distractions thru the viewfinder, only the big red horseshoe to center your target.
When you order the sight, you have the option of getting a discounted ARD filter (killflash) for $24. I thought, what the heck.
![Image]()
You get a slim rubber bikini cover for the lenses, and it fits well with or without the ARD in place.
One CR-2032 battery same as the FastFire, I can get a sheet of 10 or 12 for $6.
I zeroed for 100 with the tip of the Chevron, then shot a couple 3-4 inch groups at 200. For sure not as precise as a 4x or 7x scope, but better than a mere dot if you want to lob bullets out further. I plan to try 300 and 400 yard next time out.
The holdovers on this and on the two Primary Arms prisms I had seem close to being right on. One was on a x39 AR that I ended up selling with the carbine, and the other was a 3x prism that I ordered a few months ago.
The features of a prism are nice, etched glass so even with no battery you still have a reticle, and an adjustable diopter for older eyes. And just a bit of magnification for reaching out there.
But the prism has a short, barely 3 inch eye relief, so it has to be mounted over the action. I don't like doing that, but spent a week trying to get the prism mounted way back over the Minis peep sight. I just couldn't stand having to use a cheek riser and having the sight sitting way up there exposed., so I returned the sight to PA.
You can see with this sight mounted on my Mini that it could be lower if not for the Picatinny base which adds a good 3/8" to the height.
If the Samson has holes for the Trijicon 4 bolt pattern (does it ?) then bolting the MD-21s directly to the Samson would get the sight low enough to provide a co-witness of sorts if that is important to you. I'm not worried about co-witness on a Mini.
If it matters, i can barely see the tip of my front sight thru the Tech rear even with the mount I have.
![Image]()
There are a bunch of nice mounts, both Q.D. and fixed clamp from aftermarket sources for the Trijicon pattern, some costing as much as the MD-21 sight (around $200).
Some might get you lower than the one that comes with the PA sight.
As it is, the sight is the perfect height for me, slightly lower than the bottom battery Fastfire was .
Another pleasant surprise was the sensitivity of the Autolive shake awake feature. it's just right.
I have a $350, U.S. made Sig X Pro Compact RDS on my 365XL.
If I leave it in the on mode, walking across the floor of my cabin (floor joists over a crawlspace) the vibrations kept turning the sight on, so now I leave it turned off until I want to use it.
Out camping or whatever, I'd leave it on and trust that it would shut off.
It's so sensitive, and my floor lees than solid, that it kind of defeats the shake awake - battery saver/always ready feature.
This Primary Arms MD-21s shake awake sensitivity is just right.
I left the sight on, and despite walking heavily around, the sight turned off in 2 minutes like it was supposed to.
Bumping the Mini or picking it up and sighting, the reticle is back on every time. That's how they should work.
The ONLY thing I'd wish for is having a 2x version.
PA makes a couple of very nice magnifiers for these 21mm sights, a 3x and a 6x. The swing out mount just requires a stiff pull and it snaps out of the way, no release to hit.
But while the RDS has no set eye relief, the magnifiers do, just a couple inches, so it would never work out on the Scout rails.
But for you guys that are fine with the over the action Picatinny rails, the MD-21 sight and a 3x magnifier would be awesome.
Primary Arms sights are Chinese made. I don't know who makes their stuff for them, but they are on top of their game.
There is a lifetime, no hassle warranty on all their products.
(Sig only warrants any of the electronics of their sights for 5 years, after that you are out of luck).
I'm sure some have sent PA optics in for defects, but I haven't heard of any. They are solid optics.
www.primaryarms.com
I started out preferring the T.V. screen sights like the FastFire over the tube style dots as they seemed to offer better peripheral vision, less of a "tunnel" effect. And the reflex sights like the FF and Venom are much more compact and lighter than a 3 to 8 ounce Tube sight.
The Fastfire on its Picatinny mount out on the Ultimak is low, but just a tad high for my cheek weld. Due to the battery and electronics being under the screen, they will never be as low as tube sight with battery and electronics on the side.
I've been wanting to try the flush knob SLX from Primary Arms for a while. Shake awake, 3.8 ounce tube sight w/ 2 MOA dot.
But I think I did even better with their GLX MD-21s.
It is a 5 ounce sight with Shake Awake (PA calls it Autolive) and a solar panel on top. Supposedly the solar doesn't just kick in when the battery gets low, the sight will run on solar while you are shooting outdoors, so basically the battery is the backup instead of the solar option. Here I turned the carbine so the panel could get the rising sunlight, the first time it had "seen the light".
But the kicker with this sight is it doesn't have just a 2 or 3 MOA dot, it has the ACSS reticle like some of their scopes and prism sights.
Now instead of a round dot, I can get more precision as I place the sharp tip of the Chevron top on the target.
With the top sighted at 100 yards, the "armpit" of the Chevron is 200, the bottom arms of the Chevron are 250, and the holdover dots are 300, 400, and 450.
I'm talking here about the x39 cartridge for the Mini-30.
The manual comes with the values for about a dozen cartridges, of course these need to be checked with actual range time to "fine tune".
The two buttons on the left side are big and easy to get to.
Press and hold both for a few seconds turns the sight on or off.
A quick press of the + or - button adjusts the brightness, and it can be made very bright. I have no problem in the high desert sun and I keep it turned 3 or 4 steps down from max.
The optic comes with an AR type riser along with a spacer of 3/16" to fine tune the height, and the Picatinny mount.
The sight can be cycled thru various reticle options by holding either button for a few seconds. You can have just a Chevron, just a horseshoe/donut, have both without the holdovers dots below, etc. If I was just target shooting at long range, I'd remove everything but the Chevron. Going into a buiding to check out a noise ? Set it to horseshoe only, no other distractions thru the viewfinder, only the big red horseshoe to center your target.
When you order the sight, you have the option of getting a discounted ARD filter (killflash) for $24. I thought, what the heck.
You get a slim rubber bikini cover for the lenses, and it fits well with or without the ARD in place.
One CR-2032 battery same as the FastFire, I can get a sheet of 10 or 12 for $6.
I zeroed for 100 with the tip of the Chevron, then shot a couple 3-4 inch groups at 200. For sure not as precise as a 4x or 7x scope, but better than a mere dot if you want to lob bullets out further. I plan to try 300 and 400 yard next time out.
The holdovers on this and on the two Primary Arms prisms I had seem close to being right on. One was on a x39 AR that I ended up selling with the carbine, and the other was a 3x prism that I ordered a few months ago.
The features of a prism are nice, etched glass so even with no battery you still have a reticle, and an adjustable diopter for older eyes. And just a bit of magnification for reaching out there.
But the prism has a short, barely 3 inch eye relief, so it has to be mounted over the action. I don't like doing that, but spent a week trying to get the prism mounted way back over the Minis peep sight. I just couldn't stand having to use a cheek riser and having the sight sitting way up there exposed., so I returned the sight to PA.
You can see with this sight mounted on my Mini that it could be lower if not for the Picatinny base which adds a good 3/8" to the height.
If the Samson has holes for the Trijicon 4 bolt pattern (does it ?) then bolting the MD-21s directly to the Samson would get the sight low enough to provide a co-witness of sorts if that is important to you. I'm not worried about co-witness on a Mini.
If it matters, i can barely see the tip of my front sight thru the Tech rear even with the mount I have.
There are a bunch of nice mounts, both Q.D. and fixed clamp from aftermarket sources for the Trijicon pattern, some costing as much as the MD-21 sight (around $200).
Some might get you lower than the one that comes with the PA sight.
As it is, the sight is the perfect height for me, slightly lower than the bottom battery Fastfire was .
Another pleasant surprise was the sensitivity of the Autolive shake awake feature. it's just right.
I have a $350, U.S. made Sig X Pro Compact RDS on my 365XL.
If I leave it in the on mode, walking across the floor of my cabin (floor joists over a crawlspace) the vibrations kept turning the sight on, so now I leave it turned off until I want to use it.
Out camping or whatever, I'd leave it on and trust that it would shut off.
It's so sensitive, and my floor lees than solid, that it kind of defeats the shake awake - battery saver/always ready feature.
This Primary Arms MD-21s shake awake sensitivity is just right.
I left the sight on, and despite walking heavily around, the sight turned off in 2 minutes like it was supposed to.
Bumping the Mini or picking it up and sighting, the reticle is back on every time. That's how they should work.
The ONLY thing I'd wish for is having a 2x version.
PA makes a couple of very nice magnifiers for these 21mm sights, a 3x and a 6x. The swing out mount just requires a stiff pull and it snaps out of the way, no release to hit.
But while the RDS has no set eye relief, the magnifiers do, just a couple inches, so it would never work out on the Scout rails.
But for you guys that are fine with the over the action Picatinny rails, the MD-21 sight and a 3x magnifier would be awesome.
Primary Arms sights are Chinese made. I don't know who makes their stuff for them, but they are on top of their game.
There is a lifetime, no hassle warranty on all their products.
(Sig only warrants any of the electronics of their sights for 5 years, after that you are out of luck).
I'm sure some have sent PA optics in for defects, but I haven't heard of any. They are solid optics.
Primary Arms GLx MD-21s Push Button 21mm Microdot with AutoLive - ACSS-CQB Red Dot Reticle
The GLx MD-21s is a high-performance micro dot optic, built for superior agility and precision from close-quarters to intermediate range.
www.primaryarms.com
