On Target Review: Arsenal SM-13 Optics Mount

Arsenal's SM-13 AK Optics Mount-- a minimalist wonder
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by  Robert Kay

Arsenal’s SM-13 AK optics mount is a minimalist wonder

I sense a trend in the marketplace. As the AK platform gains in popularity in the U.S. market, more cool items are starting to appear. Just a few years ago if you were looking for parts to adorn your AK, there wasn’t a lot available. Seems like you’d have to go to online to Gunbroker.com or attend a rummage sale in Peshawar.


No need to visit the tribal areas of Pakistan. A case and point is the new offering from Arsenal, the SM-13 optics mount. According to Arsenal, the new product comes to the civilian world directly as a result of a military contract. (For whom we don’t know). The objective of the contract, says the company, was to build a “light-weight, precision, and highly rigid scope mount”.

What they came up with is pretty impressive.

Fit and finish on this one piece, anodized black, CNC precision-machined item is gorgeous. And, it’s light. Manufactured from aircraft grade aluminum alloy, it weighs only 5.76 ounces.

I had the opportunity to take the mount out for a spin with Brian Takaba, owner of X-Ring Security located in Waipahu. Brian brought along a brand new Arsenal 7.62 x .39 rifle so we spent a morning at the range putting the SM-13 through its paces. A gunsmith by training, he sells AK mounts at his shop and was particularly interested in checking out the SM-13.

The low slung SM-13 offers an ample amount of real estate–you can mount just about any kind of glass or a combination thereof. Note the furrowed rail which allows you to use the iron sights.
As anyone who has owned different AK variants knows, rifles from different manufacturers all seem to have slightly different specs.
Thus, there’s no one size that fits all so adding a mount to an AK can be an exercise in futility or at worse, could lead to a personality disorder. Certainly that won’t be your fate with the SM-13.
But I’m getting ahead of myself.
Brian has a very skeptical nature and his first impression of the SM-13 was that it was “a little big and long.” It is long—about 7.5 inches to be precise and it covers the area from the end of the top cover to the rear sight leaf. The large amount of real estate comes in very handy.

The advantages are that you can attach more than one optic at the same time.  Or you can attach a full-sized scope such as the CMR from Leatherwood.   Once we got the mount clamped on, Brian’s attitude changed. The mount is engineered to sit extremely low atop of the receiver—and as Brian said, it fit the contour of the rifle perfectly. Clearly a lot of engineering has gone into this mount. The sight line to bore-axis, which allows the shooter to minimize the compensation required by trajectory arcing, is shortened because the mount is so close to the receiver.

This is very desirable.

Another aspect we really liked was the “slot” or furrow down the center of the rail which allows you to actually use the iron sights when the mount is attached. (He noted that none of the other sights he sells at his Waipahu shop have that feature).

The castle nut adjustment for the QD lever was the secret sauce. It allows you to use the mount on a variety of AKs of different dimensions by finely calibrating the fit.Attaching the mount to the rifle was a simple affair. The only adjustment is a tweak of the castle nut that adjusts the QD lever’s tension. Clamp it down and the result is a very solid fit.
Attaching the mount to the rifle was a simple affair. The only adjustment is a tweak of the castle nut that adjusts the QD lever’s tension. Clamp it down and the result is a very solid fit.
It also provides latitude. As we mentioned earlier, not all AKs are built to exactly the same spec. The castle nut allows you to attach the mount to rifles of varying specifications by precisely calibrating the castle nut adjustment.
So how did it work for us?
The mount faithfully held zero—two inch groups at 50 yards the whole day. This pattern was repeated, even after removing the scope and putting it back on. The SM-13/HD Mico combination was deadly.  The red dot was perfectly centered which made it easy to ring the gong. 
However just slapping on a scope and expecting an ergonomic fit is asking a lot. We were pretty lucky that the geometrical equation that figures in the scope mount height, the scope’s optical axis and the ergonomics of the buttstock perfectly complemented each other. It didn’t hurt (in fact it helped enormously) that Brian purposely added an AK buttstock with a high check weld. The point I’m making is that even with a first class optics mount, such as the SM-13, all your ducks have to be in a row to make your red dot sight usable.
If one factor is off, the ergonomic equation is not going to work and you’re not going to have a very enjoyable experience. 
The QD lever worked just fine but maybe in the next iteration, it could be a bit beefier. Fit and finish on this scope mount were superb.
Fortunately, except for a nasty wind that day, our experience was quite positive.
My suggestion is that before you buy a scope explicitly for your AK, try it with your rifle/mount/buttstock combination and see what the fit for you is like. You may decide the Ultradot HD-Micro, or a similarly configured scope, is too high and perhaps you’re better off with a reflex style unit such as the FastFire III which sits much lower.
OK, so what didn’t we like about the SM-13?
Before I answer that, I should preface by saying that our criticism was minor or manini, as we say in Hawaii. Brian felt that the “One thing that could be improved was to add more notches on the castle nut that adjusts the amount of tension on the QD lever. It seemed like one notch was too tight and the next was too loose.”
My only comment was that the QD lever, while not feeling fragile, was made of pressed steel rather than being milled like the rest of the mount. That said, it worked just fine.
Our conclusion is that this is a very good scope mount. The length of the picatinny rail provides you with enough real estate to add any kind of glass you want and, the capability to hold zero.
In Brian’s words, “My professional opinion is that I would highly recommend this mount to anyone mounting a scope on to an AK.”
The SM-13 retails for $129.99—double the price of the cheap Chinese-made scope mounts.
As they say,  you get what you pay for.
Check out the recent review that my colleague Rob Ski of the AK Operator’s Union recently posted on this product. He concurs that this is a very good product.

A big mahalo goes to Brian of X-Ring Security & Firearms for helping us with this review.

Photos courtesy of On Target Staff.

Questions? Comments?  

Contact us at ontargethawaii@gmail.com

Rob Kay writes about firearms for Hawaii Reporter and is the author of How to Buy an AK-47.
Read more of Rob’s articles on OnTargetHawaii.com