Straight flute gun drill - GIF

[Altair]

Straight flute gun drill.




Previously:

Homemade button rifling press - video
Naval gun rifling cutting bit - photo

[Christophe Mineau]

These Gun drills are the exact same we use on hard wood , ebony, boxwood ... in woodwind instrument making.
In this case we use compressed air instead of collant.
I think I have a tool already showed here explaining my setup to do such boring operations and the copler I made to drive compressed air in the shaft.

[schuylergrace]

Is there any benefit to this drill configuration (the cutter arrangement, not the cooling) beyond that it appears to be really good at clearing chips from a deep hole. That's a plenty good reason to use one in some situations, like I don't know, making a gun barrel bore. But I wonder if there are other ways it excels and might be useful. Any drawbacks? I assume it probably cuts less aggressively.

[piper184]

Supposedly the main advantage to a single cutting edge is that it does not have a tendency to wander sideways like a standard drill with two cutting edges.
As long as the bore is straight, it can be reamed to final size later. I think originally they used a spoon type bit to drill out the bore. I find this kind of work on a lathe fascinating. Doing it by hand even more so.