Month: June 2005

Rifling

Posted by on June 3, 2005

Guy Lautard lives in Vancouver. He is what the Americans call a home shop machinist. The British would call him a model engineer. He has made a point of collecting some very useful hints and tips from correspondents all over the world and publishing them. Three books so far ” Machinist’s Bedside Reader”, “Machinist’s Second Bedside Reader”, and Machinist’s Third Bedside Reader.” They are among the best books about lathe and milling machine work and associated hand work I’ve ever seen. I can do work on my lathe far exceeding anything I expected because of those books. The fourth should be out anytime now and I’ll certainly be buying it.Bill Webb is a gunsmith in Kansas, of long experience. He builds bench rest rifles among other things. A few years ago he got tired of what he considered iffy quality in the available barrels and set about making his own. He designed and built his own machine, that drills reams and rifles. It is probably the first machine that does all three operations. Built from scap and readily available components like pillar block bearings at minimal cost. He was already corresponding with Lautard, and when Lautard heard of Webb’s successful machine he arranged to film it.The objective of the tape is to provide the fine nitty gritty detail that had before not been available. In three hours it sure does that. There are only two possible shortcomings. Not much is said about barrel steel, and Webb doesn’t make his own gun drills and reamers. He reckons it’s not worth the effort considering that top quality tools are commercially available, in carbide no less. As he makes barrels for his customers’ rifles he’s right, as carbide tools will probably make a couple of dozen barrels before they need sharpening. The cost per barrel is therefoe negligible. But as far as I know they are not cheap for the guy who wants to make the occasional barrel. As for the rest, it is as detailed and complete as could be imagined, with drilling speeds and feeds, oil pressures and temperatures, etc. Nothing left to the imagination.Although Webb doesn’t make his own drills and reamers, he does make his own rifling cutters as they are not commercially available. His instructions for that are as complete as the rest. Those on a tight line might want to make their own drills. They can be made more simply than the commercial drills at the cost of some speed in use. In WW2 Bren gun barrels were drilled with a simpler drill than the more usual type, that could be made quite easily. If the pressure oil feed is dispensed with it becomes easier still.For some calibres, not many unfortunately, economies can be made by using the same gun drill for two calibres. 45 ACP, 45 Colt and 458 Win Mag come to mind. The handguns are 451 groove diameter. The 458 is 458. That’s only 7 thousandths difference. Use the smaller drill for both, then it just needs an extra reaming operation for the 458.As for reaming, a standard machine or chucking reamer of the type readily available should do quite nicely, if ground to the right diameter with a suitable lead and a shank suitable for sweating to a pull tube. I have no doubt that Somta would adapt a standard reamer at modest cost.In early times the gun drill was a simple D bit. About 1980 the Cardew brothers, air rifle specialists of London, made experimental barrels with D bits, D reamers and a simple rifling cutter all of which they made. Lacking high pressure oil feed and chip removal they had to stop drilling every 3mm to clear the chips and apply some cutting oil. Consequently it was a long job. But it got done, successfully. All on a Myford lathe. The results were published, in “Air Gun World” I think. I still have a copy somewhere.To return to the Webb machine, anyone who wants to know precisely how to make barrels and doesn’t mind spending a few bucks could not do better than buy the Lautard tape. Just be warned that it only plays on a VCR and TV that will play the north american NTSC format. Price last time I checked was about $90 but that was a few years ago. Worth every cent. And like I said it’s probably available on disc.As a final word, the early rifling benches were very simple. I have a picture, unfortunately of only part of the machine, but the main pull rod that pulls the cutter through the bore and imparts the twist is wood, with the spiral groove cut into it. How simple can it get?[Originally posted to SATalkGuns -- Admin]