The FNH SCAR 17S was a perfect platform to test the new U.S. Optics SN-4 DFP scope. Loaded with Black Hills ammo, it produced excellent accuracy out to 400 yards and beyond yet was still maneuverable at close range.
The SN-4 has been one of U.S. Optics’ most popular scopes for years. It has evolved a great deal over time and remains the choice of some pretty serious shooters—not only operators, but world-class competitors. The SN-4 is extremely versatile—it can be used as a red dot-type optic at close range and can also be dialed up to 4X for longer shots. This is great for most, as few operations occur beyond 100 yards. It allows for necessary precision at distance yet provides a fantastic field of view at closer ranges. The original scopes were a bit bulky, but that has certainly changed. Originally offered with a circle-dot reticle, the later models came with a chevron and even a few custom reticles. U.S. Optics can even design custom reticles to suit a customer’s needs.
When it comes to dual focal plane scopes, the idea is to have the ranging or bullet-drop compensation portion of the reticle in the first focal plane. It could be lines, dots, circles—whatever is used to hold over on a target or used to range. That way it was consistent without regard to magnification. The aiming point, or crosshair, is in the second focal plane and will not change with magnification. While dual focal plane scopes were generally designed for longer range, U.S. Optics recently applied this very theory to the SN-4, making it practical for the typical police carbine.
The SN-4 DFP uses two of the most popular reticles specified for this scope over the years, the DOE MK II and the circle dot. The DOE is in the front focal plane. This reticle has proven excellent for ranging out to 300 yards and even beyond, and was designed specifically for tactical use. It provides lines in various thicknesses that allow measurements for ranging, as well as two excellent lines for bullet-drop compensation. Graduated at 8 and 16 MOA, they make it pretty easy to divide into 2-MOA increments.
The second reticle is the circle dot. This is in the rear or second focal plane. It consists of a large circle with a dot in the middle. The center dot is 2.5 MOA, allowing for a great aiming point that is very similar to many of the red-dot scopes. The larger circle has a 24-MOA outside diameter with an inside diameter of 16 MOA. It allows for holding a dot at longer ranges and centering the threat at close ranges. It is really a very versatile reticle and the one that has been on my personal SN-4 for years.