Scope Mounting An Airgun Dovetail Receiver

The airgun brought to me was a modern, high-velocity .177 caliber model with a fully rifled eighteen inch barrel. The rifle featured an under-barrel cocking lever. While the gun bore no name, it showed excellent workmanship. One little problem arose, however, as I tried a standard 3/8-inch dovetail on the slotted receiver. It wasn’t even close to a fit. I then tried a few bases and finally chose to use a pair of rings with integral bases made in Australia.

The split half of the base clamp was part of the dovetail base and did not allow for enough spreading to fit the receiver slots without the possibility of breaking the wing from the base. So, as a measure to assure flat contact of the base wings in the receiver slots, I did not attempt to spread the narrow base wings to fit wider receiver slots. Instead, I chose to mill the fixed side of the dovetail base which was also the more precision way to go.

I then cut the scope base slot wider using one of Brownells dovetail cutters in the milling machine. This milled the fixed side of the dovetail openings from an existing 0.405-inch to 0.435-inch. I was then able to slide the base in place where the side screws could tighten them securely. The scope was mounted 1 5/8 inches above the bore with three inch ring centers leaving ample viewing above the existing open

With an absence of recoil, a shorter eye relief is usually desirable on an airgun. sights. Eye relief was perfect with the Tasco four power scope as the rifle was shouldered. As a bonus, the scope really enhanced the overall appearance of the rifle. Testing The Scoped Airgun The newly scoped airgun resulted in a well-balanced gun that is easy to shoot. Loading the gun required about 30-foot pounds of the under lever to cock and load.

With the cocking lever at a right angle to the action the breech opens about three inches, leaving room for the thumb and forefinger to load a single pellet. This model does not have an automatic safety. The manual safety lever is positioned within the trigger guard, which is pulled rearward to a safe position. Trigger pull is about three pounds with nominal creep but let off was crisp. The gun balanced perfectly when shot over sandbags or off hand.

Accuracy at 25 yards was about an inch for five shots using a sandbag rest. Conclusions Mounting a scope on an airgun makes it an excellent choice for shooting targets and small game like rabbits, 177 caliber pellet into the breech of the cocked airgun. There is ample room for loading with the scope object lens well back of the loading port. Target shooting is a pure pleasure compared to open sights, particularly with aging eyes. squirrels and small varmints.

Before attempting to mount a set of scope rings on a grooved dovetail receiver be sure the receiver slots and dovetail base blades are compatible. Milling to correct size is the best way to go. Not all airguns pose the ring mounting difficulty encountered with this one but it was worth doing, leaving me a very pleased customer. AG