Model K10 High Standard Shotgun Open Rear Sight

Model K10 12 gauge shotgun A was turned over to me for repair and sighting correction. The old gun appeared to be in very good condition but had been dropped, sustaining impact damage to the variable choke adjustment ring. The gun was reportedly hitting very low and to the left of the aim point at 50 yards when shooting Federal Foster-style one ounce rifled slugs. The customer had the variable choke set at full choke and was shooting while sighting down the rib, using only the front brass bead as a sight.

My preliminary evaluation revealed some impact damage to the choke adjustment ring, which was later corrected on the lathe. As given to me, the choke setting was at full choke. As a baseline for accuracy and point of impact, I shot the gun at 50 yards using the same type of Federal slugs. When the choke was set on Improved Cylinder, the 50 yard point of impact was about 11 inches low and slightly left.

A Temporary Rear Sight As a test measure for sighting, I made a temporary rear sight at the height I felt would work and taped it to the rib just forward of the receiver. I had filed Bottom a shallow notch in the sight for the first tests approximately 0.250" above the rib. The slugs were now impacting very close to point of aim at 50 yards, so I suggested use of a small, openleaf style sight for the gun, a type of sight I could readily make.

The sight would be cut from angle iron material and milled to size with a small 0.075 half round notch for the front bead. The part would be attached permanently with J-B Cold Weld. Making And Attaching Sights Apiece of metal 0.010" thick, formed at a right angle, was cut from an existing piece of rectangular tubing. The

Bottom When the bead fills the notch while sighting, the notch size is just right. Top top of the rib by only 0.085". This is basically a very small open sight just allowing the front bead to fill out the notch with the eye about 16 inches from the rear sight. I blued the finished sight and attached it permasight base was limited to thickness so as not to interfere with viewing over the shotgun rib with the bottom of the rear sight notch aspect clearing the nently with J-B Cold Weld.

The roughened finish helps prevent glare. Note the milled-out radius at the front for correct leaf thickness and better sighting. Bottom This proved to be a very effective method of shooting rifled slugs while deer hunting. Conclusions When it comes down to sighting a smooth bore shotgun with rifled slugs, few perform in the same way. Often a plain, open rear sight coupled with the factory front bead is very effective for slug shooting and doesn’t change performance when using the shotgun for shooting birds.

It’s a very practical way to go and the cost is low. AG