Fitting A Forearm Hanger Extension On The Knight KP-1 Rifle

There are several styles of single-shot, break-frame rifles with accuracy problems traceable directly to the way the forend is attached to the receiver. The Ruger Number 1 and Knight KP-1 are notable among these. This treatise will deal with solving this problem on the Knight KP-1 singleshot rifle. The Knight KP-1 single-shot action is used on muzzleloader, centerfire and rimfire barrels. A different forearm is, of course, used to fit each style of barrel.

Unaltered, the forearm is attached to a short hanger which is an integral part of the receiver and locked in place with a special latch on the underside of the forearm. Each forearm style leaves the barrel free floating with no contact at any point along the barrel channel. In this way the barrel is allowed to vibrate freely as the rifle is fired. This approach is often thought of as away to deliver best accuracy from the rifle design.

However, such uncontrolled barrel vibration can also be the very cause of poor accuracy, typically manifesting as vertical stringing on the target. This is particularly true of lighter barrels using high intensity cartridges such as the .300 Winchester Magnum, .30-06 Springfield and the like. My experience, thus far, with the Knight KP-1 rifle has included the .300 Winchester Magnum and the .30-06 Springfield which I why I mention these cartridges specifically.

The theme of this text will cover a KP-1 I modified chambered for .30-06 Springfield. Improving KP-1 Accuracy After much experimentation with the KP-1 rifle it was discovered and proven that applying forend pressure to the forearm greatly improved accuracy by dampening barrel vibration at a point near mid-barrel. This required the addition of a forearm hanger extension attached directly to the existing short forearm hanger on the Knight KP-1 rifle receiver.

The challenge then was to devise a means to fit and attache a forearm hanger extension. Close observation of the KP-1 receiver showed a milled slot extending into the forearm hanger. This precision milled slot provided a perfect place for a length of 3/8-inch square steel stock. The only alteration needed to fit the steel extension beneath the barrel was the

The escutcheon is positioned in the old sling swivel hole and sling swivel moved forward about an inch. addition of a short taper so the piece would slide back to the receiver. The reinforcement webs in the composite forearm were milled out to make room for the new hanger extension using a 3/8-inch end mill. This slot also served as a perfect forearm/ hanger guide. As a means of attaching the forend to the new hanger extension, the front sling swivel hole was used.

A 1/2-inch diameter brass escutcheon was countersunk at the bottom of the forearm. A hole for the number 10-32 attaching screw was drilled and tapped into the front of the forearm extension bar. A stainless steel socket head screw was used. The original sling swivel was repositioned 3/4 inch above the forearm attachment screw. Contact Bedding The Forend Tip A major part of the forearm hanger application includes pressure bedding the forend tip.

The principle here involves dampening of barrel vibration tones (barrel whip), thereby improving accuracy. The amount of upward lift pressure at the forend tip is dependent on barrel diameter as well as caliber/cartridge intensity. In the case of the .30-06 barrel discussed here, the barrel at the pressure point measures 0.650 inch, which is comparatively small.

In this case controlled pressure between 6- 10 pounds of upward pressure is ap- Brownells Steel Bed was used as a bedding material. plied near the tip of the forend. This is later controlled by loosening or tightening the forend hanger screw as accuracy is monitored. Following the usual procedure of epoxy bedding, the forend tip is masked and release agent is applied to the barrel. Brownells Steel Bed is used for the bedding, which forms perfectly around the barrel contour and sets hard as steel.

Sides of the forend are masked to prevent bedding material from making any un-

Torque is being applied with an Allen wrench. Shown above is the forearm with the newly bedded forend tip. wanted contact. Ample space must be allowed for bedding material beneath the barrel. As the epoxy bedding is applied, the forend is lowered 0.150 inch to allow room for a draw down by the forend tension screw if needed. I applied a wood spacer between the barrel and forearm extension hanger to control this prespacing as the epoxy bedding was applied and allowed to set.

Following clean-up, everything looked neat and precisely in place. Testing The Work For Accuracy With previous accuracy of the 30-06 Springfield barrel already known to be very erratic, a marked improvement was anticipated. The scope was re-mounted on the carefully reassembled rifle. I applied approximately seven pounds of uplift pressure on the newly bedded forend tip and tested several five-shot groups using the same loads as those used prior to the work performed on this rifle.

In this particular testing I used wellprepared Winchester cases loaded with Redding competition dies. Accuracy results were immediately very encouraging as groups at 100 yards were now in the normal range for a 30-06 bolt action rifle. All undesirable vertical group stringing 30-06 Springfield with a Weaver target scope used in testing. From this picture one would not know a special forearm hanger extension is used to hold the forearm precisely in position for improved performance. 30-6 rifle.

Groups inside the wavy lines were shot at 100 yards before forearm bedding. Note the vertical stringing. Two five-shot groups pictured in the rectangular square at right were shot after work was done to bed the forend using the forearm extension hanger. was now corrected. Where accuracy can be so dramatically improved with the simple addition of a forearm hanger extension and bedding the forend tip, it definitely should be done.

It is a very straightforward gunsmithing procedure and you are likely to see a very satisfied customer as a result. AG