I'm simply having a .62cal Flint "smoothbore" barrel rifled.
Normally when a rifled barrel is made, it is drilled/reamed out to a certain diameter for the caliber it's intended to be...the "bore diameter"...and is still smooth at that point...and essentially to sell it as a "smoothbore" it's basically done.
But to make the same barrel a rifled barrel, the next step is that a proper sized cutting head is pulled (or pushed) through the open bore to cut the spiral rifling grooves into the metal. (the breechplug has to be removed so the cutting head equipment can operate through the empty barrel)
After that, the untouched spiral strips that were originally at smoothbore diameter remain just as they were but will then be called "lands"...and in this case there will be a corresponding number of alternating grooves that will have been cut .012" deep by the cutting head and it's 6 square cutting fingers.
They produce square bottom grooves around the bore...looking just like the rifling looks in any muzzle you've probabley ever looked down into. (as opposed to asking for what is called "round bottom grooves"...rarely done). PS: I'm having the rifling cut at a 1:72" rate of twist.
The only difference with my barrel is that instead of all the steps being done at once, I first bought the barrel as a "smoothbore", shot some deer with it for that experience...now I've decided to have the rifling work done and had to send it to a barrel maker who has the equipment & knowhow to add the rifling step, ie: Ed Rayl in West VA...$65 + return UPS.
