Loading Ramp Bedding Pillar Combo Installation

In my long journey as a rifle builder there have been numerous improvised and modified parts adaptable to the performance improvement of many of these rifles. Such was the case with a Model 700 action set into a Bell and Carlson target stock, made over as a single shot and equipped with a special dual purpose cartridge loading ramp and bedding pillar. This rifle is also a switch barrel with two bolts The stock used is a Bell and Carlson with two-point bedding system.

A central action screw will be added through the hole back of the loading ramp/bedding pillar. The flat side surfaces of the cutout rest squarely onto the side rails of the loading ramp/bedding pillar. The bolt is pictured here half forward as it would move through the channel in the cartridge ramp feeding a cartridge into the chamber. and four barrels, chambered for .260 Remington, .270 Winchester, .204 Ruger, and 5.6×44 (.223 Improved) of my own design.

Getting To The Work There was nothing mysterious about this work. Bedding pillars are commercially available for this purpose but not this particular one. In American Gunsmith April 2013 ("Davidson Loading Ramp Remington Rifle Installation") I covered the installation of a Davidson Loading Ramp on a Model 700 Remington short action rifle. The part is bonded into the receiver race, originally occupied by the magazine box. These ramps are normally cartridge specific to accomplish smooth cartridge feed.

But this loading ramp does not have a pillar bedding feature. In this new design, a unique loading ramp serves a twofold special purpose, interfaced between the laterally opposing races in the receiver (where the magazine box was removed) and built up stock support from below. The new loading ramp actually serves as a solid bedding pillar, bonding solidly in place with Brownells Steel Bed. This adds measurable support to the central bedding area where the Model weakened somewhat by the magazine cutout.

Above, the loading ramp/bedding pillar is bonded into the stock occupying the space where the magazine box was removed. The rifle bolt passes through the slot in the ramp, pushing the cartridge forward into chamber. The new (third) action screw passes through the front of the trigger guard from below and between the trigger assembly and rear of the loading ramp/bedding block into the underside of the rifle receiver. Each loading ramp/bedding block combo is unique to the rifle stock and action being worked on.

Precise measurement must be taken in making and fitting this part. Here I like to work with cast aluminum which is easy to machine and has excellent durability and maintains good dimensional stability. Some space is allowed at the sides and bottom of the block for the bedding material. The old magazine housing makes a good pattern. Always be sure to place the new bedding block/loading ramp in position on the rifle from below to be sure of proper bolt clearance.

As a means of assuring solid square contact between the bedding block and the machined races on the receiver, I use a screw-on cleat to attach the bedding block to the receiver as the Brownells Steel Bed bonding material sets. There is a telltale, filled-in screw hole in the bolt channel as evidence of this. A poorly fitting receiver rail would present a real problem, particularly with use of a central action screw.

The third action screw is added, positioned back of the loading ramp/ bedding pillar entering the action immediately behind the new loading ramp where a semi-circle notch is cut at the rear of the ramp. Here I used a 10-32 threaded screw with This screw replaces a wood screw used here to secure the front of the trigger guard. The third screw adds strength to the action as the screw pulls it into the bedding block. American Gunsmith Reader Services 1.

The front screw enters a newly tapped and threaded hole. These two screws provide a great deal of stability to the action with the bedding pillar interfaced between them. The result is a very sturdy bedding system converting a weaker repeater action into a thoroughly-bedded, single shot target rifle. socket head to match the other two receiver screws. It was necessary to enlarge and re-tap the smaller existing receiver screw hole. This central screw also serves as the front trigger guard attachment.

There is absolutely no action springing in the stock as these three screws are alternately torqued. Dial indicator tests show absolutely no barrel movement in the forend channel as action screws are alternately loosened and tightened. This four-barrel rifle is shown equipped with a Sightron S-TAC 4-20×50 rifle scope mounted on a Tally Picatinny mounting system. The rifle wears a Criterion 8 twist, 26" barrel chambered in 260 Remington. Exemplary accuracy is shown in the two series of groups shown.

Used were a variety of bullets and components, including bullets by Berger, Nosler, Sierra, Hornady, and Barnes. All of the five-shot, 100-yard groups shown here are sub-half inch with an average in the 0.34". I installed a Talley Picatinny scope rail, adding to the rigidity to the Remington 700 action. This has been proven in tests conducted using specially mounted dial indicators. This, in conjunction with proper coaxial scope mounting, is a positive measure in accuracy enhancement.

Conclusions There are scores of things that affect precision to some degree, however small. Shooters wanting groups hovering around minute-of-angle may not notice such modifications, but I can assure you where quarter-minute groups are in the realm of possibility, there is a difference. AG