Carnell, a past Australian Sporter Class champion, is an accomplished benchrest shooter with decades of experience. In 1993 he won a Silver Medal at the World Championships, and he has placed highly in events he’s attended in the United States. But Carnell is far more than an ace trigger puller. Robert is a skilled and creative “home gunsmith” who has crafted his own custom action and built his own railguns from scratch. You can learn about these and other Carnellian creations in the “Personal Projects” section of Robert’s website.

Home-Built Rail Gun — Aussie Innovation
Below are photos of one of Rob Carnell’s most amazing builds. This liquid-cooled, tension-barrel rail gun is a great example of self-reliant Aussie engineering. The barrel runs inside a coolent-filled, large-diameter sleeve, much like an old water-cooled machine gun. This is the fourth rail gun that Rob built, and the second fitted with a tensioned barrel.

Robert explains: “My railgun design has a 1.75″ barrel under tension inside an aluminium tube filled with radiator coolant. There is nearly a gallon of coolant, and the barrel stays cool no matter how many shots I seem to fire, or how quickly they are shot. The brass nut on the front rides on a nylon bearing and can be tightened to get the best accuracy. I am a believer in the ‘tuner’ idea and this seems to work for me. The main tube is thick-walled aluminium 600mm (24″) long. There is a flange at both ends. The flange at the back fits onto the barrel before the action is screwed on. The front flange is a press-fit into the tube, then there is a brass nut that fits over the barrel and screws against a nylon washer on the front flange. The Railgun’s base is aluminium and has the standard adjustments — windage, elevation and a sighter cam. In addition, there is a 1/10 thou dial indicator for windage. This allows me to zero the indicator and shoot my group. If I need to add a bit of windage for a condition, I can quickly get back to the original position if my condition comes back.”

Home-Built Action Uses Remington Bolt
Rob’s rail gun uses his own home-made stainless action, which features Panda-spec threads and a modified Remington 700 aftermarket bolt. Not bad for a do-it-yourself project we’d say! CLICK HERE to read how Rob designed and built the action.