US Optics, based in Buena Park, CA, is a small manufacturer of custom high-end scopes and was the
repair center for the old USMC Unertl sniper scope. While USO has a variety of scope models, their
most popular scope for practical long-range shooting is the SN-3 3.2-17x44 mm. These are built to
the customer's specs, and are available with almost any combination of tube diameter, knob types,
clicks, reticles, and objective lens size. The most common SN-3 build has parallax adjustment on
the objective housing; however, the newer Turret Parallax Adjustment (TPAL) design has the parallax
easy to reach near the other knobs. The TPAL design can be customized to put the parallax and
illumination adjustment knobs on either side or the top of the turret body. USO's new 5-25x58 mm
SN-3 TPAL was designed for ultra long-range shooting.
Though built like tanks, the USO scopes exact a penalty with their size and weight. This
3.8-22x44mm SN-3 looks big even on this 50-inch-long .338 Lapua rifle.
With the USO, you can get a zero-stop many-click multi-turn elevation knob with 0.1-mil clicks and a
mil-dot or mil-hash reticle to match, or you can get MOA clicks and a MOA reticle if that's how you
are trained. With a 35-mm tube, the zero-stop EREK elevation knob typically gives at least 72 MOA
up from the zero-stop, which is roughly equivalent to a 100-MOA total elevation scope on a 20-MOA
base. Needless to say, the SN-3 has more than enough elevation for any rifle. Priced starting at
about $2000, the optical clarity and low-light performance are better than the Leupold and
This US Optics SN-3 provides 90 half-MOA clicks per turn of its EREK elevation knob; its windage
knob has 0.25-MOA clicks. The reticle has MOA hash marks to match.
The 35 mm tube on this US Optics SN-3 allows over 21 mils (72 MOA) of elevation from a 100-yard zero,
especially useful with the .338 Lapua Magnum cartridge.