Kinetic definition

We are shooters. We are manufacturers. We are KCT. This blog shares our experiences with gear, guns, ammo and more.

Check out our line of kydex holsters and magazine carriers! Holsters start at $35, and magazine carriers start at $25. Check out our ONLINE STORE.

If you have any questions or comments feel free to reply on the posts. Follow us on Facebook and Instagram!

Tuesday, February 5, 2013

PA 3X Long Eye Relief Magnifier

PA 3X LR on a PA FTS mount behind a Vortex Strikefire in a PA cantilever mount over an MBUS.

I've been looking at a different set of sighting options for the past few months, and I've come to find there's several different systems that seem to work, but as with most things, each system comes with some significant drawbacks.

Iron sights are great, and I recommend them on nearly any weapon you have, and with very few exceptions.  However, they are generally slower than a dot sight, and not as good as a magnified optic at longer distances.

I recently decided to work a pair of different sighting systems into my carbines to see how I would work each system as well which one provided better results.

To this end I picked up a few new pieces of kit, each of which will get their separate article.  The first thing on my list was the Primary Arms 3X Long-Eye Relief magnifier.  I had read good things about the PA magnifier, and more so about the 3X.  I will tell you right now, the long eye relief is worth the extra coin over the older model.  You have to be almost scope close on this one, and I can't imagine being able to maintain the closeness you need with a magnifier.

This point aside, I have to say the PA magnifier exceeds my expectations.  Now, this is before running it in the dirt, but that's on the menu.  The armored housing is robust, covered with a thick, textured rubber layer.  It is easy to grasp even with gloves, even those without great internal grip texture.

The magnifier sits perfectly above the Magpul MBUS rear sight, although only with the MBUS's aperture set to small.  If you flip the smaller aperture up, the sight doesn't have enough clearance to flip back into place using the PA FTS mount.  Nothing really big here, I'm sure it would be the same with most rear sights and mounts, but something to consider if you run the larger aperture on you MBUS (I do).

ADDENDUM: The MBUS can be used with the larger aperture open, the rubber mount on the PA magnifier has enough "give" to allow the aperture to be up, but it does put pressure on the magnifier and the mount.  A little work with a dremel or soldering iron will be enough to remove the material allowing the sight to sit aperture-up without hitting the sight.

The PA FTS mount is a great piece of kit for the price.  It's heavy, but you're not paying DD or Troy prices, you're paying 1/3 or less of that.  And honestly, the AR itself is light.  It's all the gear we put on it that makes it heavy.  So be able to run your gun and hump it from A-Z, or find a lighter option.

The FTS mount works well.  It takes a serious tug rearward on the optic to get it to flip in our out.  The flipping motion is smooth and grit-free.  There is a tiny bit of play in the mount when you yank on the optic when its mounted behind the red dot, but its nothing spectacular, and unless someone is smacking your magnifier, you'll never notice it.  This will be tested under recoil shortly.

The only thing I don't like about the mount is how the screw from the mount protrudes through the tensioning nut.  It's a slotted nut that allows the bolt to pass through it, so on the model I purchased, you cannot use a flat head screwdriver to tighten it all the way, you're going to need a pair of pliers.

To me it's not that big of a deal because the magnifier flips to the side, so I rarely need to take it off the gun, and if I do, I should have some way to do it, like a multitool.  But if that's an issue for you, it's something I noticed on mine.

After running some dryfire drills with this, I can tell you now, BLUE LOCTITE the mounting screw.  Because you're torquing on the mount every time you flip the magnifier, you are causing the mount to move back and forth on the rail, and this loosens the mount considerably and quickly.  I'd consider it a MUST DO.

The PA magnifier has a set of capped adjustment knobs for centering the red dot within the magnifier.  As I have not yet zereod the dot in its new PA mount, I will be testing this feature at the range once we get the carbines zeroed with this setup.

As far as questions about the mount go, we did up some more pics.  We'll have more info when we run it through the dirt, but here's some observations so far:

The magnifier is a little canted to the left.  This is due to the spring tension in the mount.  The dot will remain POA/POI if correctly zeroed no matter where it appears in the magnifier, so no worries on that, but I like my reticules centered when I'm coming up on my optic, one of the reasons I don't like 1/3 cowitness as much as actual cowitness.  The adjustment knobs should allow the user to center the dot, regardless of the cant.

This is the sight picture with the MBUS up and the dot on.  Low dot is because of the angle of the picture.

The mount in flipped to side position.  Note the attachment screws for locking the arm onto the pivot rod.

So far, the PA 3X magnifier has felt like a solid piece of gear, and the mount was better than I expected as well.

I'll bring another update when we get this in the dirt.

Update 6/23/13

We ran this today shooting about 200 rounds of .223.  Shooting from a range of about 50 yards to 7 yards, this thing worked well.  My eyes aren't that good as it is, and being able to go to magnification further out and snap the magnifier out of the way when moving up to closer ranges.

The magnifier worked well even when flipped to the side, and did not impede the function of the weapon in any way.   Working the BCM charging handle around the optic also caused no issues.

One issue I did notice though was that when flipped up, the wobble on the arm on the mount increased.  Previously, I used this setup on my M&P-15/22 with no issues, as you'd expect with a .22.

I never noticed any issues with the magnifier wobbling when shooting on either platform, it was something I noticed when locking the magnifier back into place behind the optic.   So far, it hasn't impacted my accuracy at all, since you need to shake the weapon pretty hard or bump the magnifier to make it wobble.

I'll keep an eye on it as testing continues, but it is something to bear in mind with this mount.   One other issue is that it does stack some weight on the weapon, which may or may not be a big deal.  after running, carrying, and shooting the weapon for about 3 hours, I could feel the added weight but it didn't hamper my manipulations of the weapon.  YMMV.

We'll keep you posted as we use it more.

 Update 8/18/13

The magnifier has been on one carbine or another the past few months, and has been getting a workout every weekend.  We have found that at the ranges that we trypically shoot at (about 30 yards or less), the magnifier is rarely used.  When working barricade and cover drills, the wisdom of PA covering the magnifier with a rubber coating becomes apparent.  The magnifier is often slammed into the dirt as the shooter goes prone or gets knocked into gear or walls during pistol transitions, and so far the magnifier has no issues. with the abuse.

One thing we did find is that when using a cheap red dot that was on its last legs and battery life, it seemed to blur out in the magnifier during 100+yard shots, making the shooter switch back to the unmagnified red dot to clear up the sight picture.

With a decent red dot, this is not an issue.


  1. Hi, was wondering if you could also give the mounting hardware you are using with this 3X Maginifier. I have your Red Dot sight, and was looking for this actual setup for my AR.


    1. We sure can. I'll see about getting expanded pics of the mount and its functions when I get out of work tonight.

  2. Sorry for the delay! New pics and detail of the mount are up, let us know if there's anything else you wanna pics or info of.

  3. I like your blog specially all the information are very great well done.
    gun optic and co-witness