Vintage race car consulting
Class A CDL
Manufacturer of F-Class stocks
Manufacturer of expander kits

Mk Ill Stock/BiPod for F-Class

This is the current generation of stock/bi pod developed for F-Class target shooting.

Weight: 3.0 # as pictured. Price: $800.

BiPod is a very rigid carbon fiber tube and aluminum billet structure with ski type slider front feet extended forward and to the side at 45 deg. to provide maximum stability. Adjustment for cant is by the attachment stud and nut. Adjustment for elevation is by eccentric attachment of the Delrin bag rider. Three different bipod heights and available and specials can be made to order.

The barrel is attached to a 1⅜” dia. main carbon fiber tube by an aluminum billet clamp allowing use of a longer barrel and removing the strain off of the receiver to barrel joint. Fit between barrel and clamp is important and should be done by a machinist or gunsmith. Barrel should have 6″ of straight 1.2500″ dia. for the clamp.

The butt plate and cheek piece are made out of Delrin, a very slippery, relatively light black plastic. This was done so the gunsmith finishing the assembly can add ballast to the butt or replace the cheek piece with steel to bring the total assembly up to maximum weight.

The laws of physics still dictate that recoil is directly opposite to the bullet direction. If the bag rider sticks in the rear bag then the muzzle will climb adding to inconsistency. If the stock mass is inline with the bullet direction there is less tendency for the climb inherent in hunting rifle type stocks. The more the center point of mass of the rifle assembly is above the centerline of the barrel, the more the muzzle will be forced down. This is the big advantage this stock has over any other stock. 4½ # of ballast can be added to the butt by replacing plastic parts with steel. Stock is shipped with plastic parts which can be exchanged for steel parts when rifle is ready for final weight adjustments.

Current testing is showing that very large diameter barrels are a distinct advantage in F-Class. Barrels as big as 1.453″ diameter by 33″ long can be used and still make the 10 Kg maximum weight.

Bag kit consists of a Protector Bunny ear bag with Delrin balls bolted to the ears to provide a low friction, small contact point for the bag rider to slide on. A 6″ X 9″ steel plate, attached by Velcro, is used to provide a base for the bag. Two ½” thick wood shims are included just in case you get a really weird firing point.

Contact information: Steve Jennings 435-850-2815

SJR Enterprises Expander with Gauge Pins

This expander uses modified gauge pins as a final operation to qualify and finish the ID of case necks.

Price $80


Parts list:
Collet Holder and Nut .284 thru .308 $39.50
Gauge Pins: .0005″ increment each 6.00
ER-16 Collet 33.00

Collet Holders for taller and shorter cases can be created on special order about 2 days, same cost.