Lightweight Keltec SU16 comes in several variants, with barrels ranging from 12 to 18 inches and with stocks that telescope or fold. The variant made for restricted states folds in the middle of the receiver instead. In most versions, the forend unfolds into a field-expedient scout bipod. The light weight and the simplicity of the design, along with a lower price than most AR15 and Mini14 competitors, make the SU16 quite popular for “sport-utility” uses. A police officer friend bought one he keeps in his vehicle for “show and tell,” and I immediately got out my parts bin.
My friend’s SU16C carbine is the folding stock version. He’s using the factory iron sights by preference because they are low-profile and weigh almost nothing. For the intended range under 100 yards, they should do fine. SU16 default sights are adequate.
While I have never seen these factory sights fail, they are plastic and lack graduated adjustments. Fortunately, for $40 Keltec offers an upgrade which comes standard only on the NFA-regulated D model with the 12″ barrel. This replacement is much more robust, is made of metal, and is protected from knocks. Unfortunately, it too lacks gradations for repeatable adjustments.
Tech Sights makes two other options at $72 to $82, one of which offers two apertures similar to an AR15A2 sight, the other a single AR15A1-style peep with the option to adjust elevation on the rear sight. Sitting farther back on the receiver than the KelTec part, they also increase the sight radius slightly. With the 18.5″ barrel of the SU16A model, the resulting iron sight resolution improves considerably on the AR15. The metal front sight tower of the 16A and B is likewise available as an upgrade for $49. Besides the increased durability, that part also extends the sight radius by placing the front post near the muzzle rather than on the gas block.
All of these rear sight options could benefit from a fiber optic front sight made by Hi-Viz. At $33, it’s the cheapest substantive upgrade of the aiming system. In my experience, this type of sight — also available for AK and AR15 — is fairly robust. The fragile fiber optic is well-protected and easily replaced if damaged. The glowing dot is just slightly below the tip, so long-range zeroing should still be done using the squared-off top of the post, while close-range reaction shooting can be done with the green dot. The point of impact will be higher, but not by enough to make a difference within 50 yards.