Originally Posted by cabelas90
Thanks all! I understand how a cut barrel is made but how are button rifle barrels made? I don't plan on cutting any corners just wonderd what was best!
A cut barrel is made by running a hook (cutter) through the barrel and removing a very small skim cut of metal to form the start of a groove. The barrel is then rotated some degree, and the adjacent cut is made parallel to the first. As the barrel is turned through a 360 degree rotation and all the grooves receive their first pass, the cutter is adjusted just a bit (a very slight bit, as in .0001" or so) deeper, and it then follows in the first groove cut, rotated slightly to the second, etc., etc, etc, ad nauseum. Cut barrels are very labor intensive, and that cutter may make 300, 400, or more trips up and down that barrel before all the grooves are cut to their final depths. And yes, you read it right, the cutter cuts one groove at a time, and only takes a very light "scratch" each time through the bore. This incidentally, is the origin of the term "start from scratch' comes from; the first pass of a cutter through a drilled blank that begins the rifling process. Yeah, there's a lot of American vernacular that originates from the gun industry; "lock, stock & barrel", "go off half-cocked", "Keep your powder dry" and my personal favorite, "the whole nine yards" among a host of others.
"Buttoning" barrels as a method of manufacture was developed in the 1940s as I recall (anyone?), and I'm pretty sure Remington's Mike Walker was involved in this. Originally, it was intended as a faster, cheaper way to rifle a barrel for production guns. In this method, a blank is drilled out to bore diameter (little less, actually). Once done, a small carbide "button" is pushed or pulled (depending on who's doing it) through the bore. The button, shaped like a tiny football, has a series of grooves cut into the surface, essentially a mirror image of the desired rifling. The twist rate is determined by the pitch, or angle that are present in the button, which rotates itself during its passage through the bore. As the button makes its way through the barrel, it literally irons that reverse image into the interior surface of the bore, leaving finished rifling in its wake. One pass, one (almost) finished barrel. Much cheaper and faster, especially when dealing with a maker whose producing dozens (hundreds, thousands, etc.) of barrels. As Michael touched on, this button somewhat limits the versatility, since they're made for one
specific bore size and one
specific twist. You can make any twist barrel and any bore size with a button; you just have to cut a new button with the appropriate twist/size in its surface, and that's the only twist that
button will ever make. With a cut barrel, it's just a matter of resetting the gearing that turns the barrel, and any
cut can be made on the same machine. Much more versatile, especially for smaller runs or custom twist/dimension barrels. The cut barrels are also rigidly controlled during the process, generally making their advertised twists closer to the truth than buttoned barrels. With the button, the twist can vary a bit if it encounters "hard" or "soft" areas of the barrel. Remember, the pitch of the cuts on the button are what causes it to rotate at a given rate, not any mechanical control.
As I said before, excellent quality barrels can be made by either method. Buy a good barrel from a quality vendor, and you'll get what you pay for.
Hope this helps!