First time cutting flutes in a barrel

[Mikado Do]

Thanks for all the info.I like Hotguns set-up(appreciate the pics).
I fully agree with the 180 degree opposing cuts to equally release any stress.Will add support to the middle of the barrel just for paranoia's sake.Custom barrels aren't cheap.
My two cent's on barrel fluting.Theoretically better cooling through increased surface area.

[AR15DCM]

Aluminum is fairly inexpensive so I was thinking of buying some lengths of 1" to practice with and see how the tool reacts at varying depths etc etc..

[steamin10]

I think that is an apples to oranges kind of thinking, and wont teach you much about any crossover. Aluminum does not behave like any of the tougher barrel materials. If you parctice on correct alloy numbers of just plain bar, I think you will have the identical feel then for a barrel material.

[AR15DCM]

For someone just learning how to use a mill I think it will be fine. Once I get more comfortable with it I will get some 4140 or something like it.

[Harold_V]

For someone just learning how to use a mill I think it will be fine. Once I get more comfortable with it I will get some 4140 or something like it.

You'd best rethink that decision. You will become familiar with how the machine operates, but how aluminum cuts is not the least bit representative of how steel cuts, in particular, tough alloys like chrome moly. You risk building a host of bad habits cutting aluminum, habits that will be totally unacceptable when machining tough materials.

This is one of the hardest lessons for the novice to learn. It borders on the impossible to run aluminum too fast, especially with home shop type equipment. That is far from the truth with steels, and tough alloy steels, especially chrome moly (and stainless). If you hope to learn anything of value in the way of machining those materials, that's the only way you're going to achieve your goal.

If you insist on using aluminum, make the transition to steel as quickly as you're comfortable with the machine controls.

Harold

[AR15DCM]

Guys, because they screwed up and sent the wrong chip tray with my mill, I haven't even set it up much less turned it on yet LOL.
I have no choice but to take one step at a time, and slow ones at that. I have aluminum stock sitting in the garage
and with the cost of 4140, I will start on the aluminum first to at least learn first hand how to set up and work the table.
Any serious milling will be done on 4140 as that is what my projects requires.

[Harold_V]

Not a problem. Do as you wish, but keep in mind the things I told you. They're a lesson you'll learn, one way or another.

Do take note, I didn't suggest you start with chrome moly. Just plain old mild steel, cold or hot rolled (1018 up through even 1045) would be an excellent material to work with, as they all present virtually the identical problems. No need to waste chrome moly.

If you machine aluminum for an extended period of time, then make the transition to steel, you're not going to have a fun day. You might consider talking with seal killer in regards to this subject, as he's been there, done that, and not all that long ago.

Harold

[seal killer]

Harold and All--

As I was reading this thread, I kept thinking about the issues I encountered when I finally started working with steel . . . and it was mild steel. And then I read Harold's final sentence. Deja vu, or something like it.

--seal killer