All I can find are homemade plans, with household materials…I’m looking for actual plans to make one out of metal, using a lathe and any other necessary machinery.
Thanks. 
isn’t that illegal?
Yes.
I didn’t say it’d be USED, just built!
Dude, I can’t explain enough how illegal this is. If you post that you still want to go through with it, I would ask why you want to know. Granted, this is an idle question with a smilie at the end, but it seems pretty suspicious.
Sorry to darken yer day, but you ain’t got any explainable motives, and even I ain’t that crazy . . .
Tripler
But I can tell ya how to do it. . . ::eep::
My dad is a machinist.
He works with CNC lathes and those types of machines.
Currently, the company he works for is experiencing a slow period. Right now, my dad has nothing to do.
He is a gun advocate, and owns quite a few.
He’s always wanted a silencer, and knows he can build one.
He has no evil intentions, has never been in trouble with the law, and is an upstanding citizen of the U.S.A. with no criminal record of any kind.
He just wants one. 
I can fully agree with the “He just wants one.”. Hell, I bought an AR-15 because “I wanted one!”, but there’s a distinct difference:
my AR-15 is legal.
If your Pop is a machinist, he should be able to make one up on his own without our help. Anyone can find instructions anywhere. Dude, asking me (or even us on the SDMB) for help is tantamount to criminal. Providing such info is very criminal. . .
Tripler
Yeah, I am a jackass. So what?
Well that’s good enough for me. It’s not like he’s Canadian or anything. Just give him the goddamn information. When’s the last time an American misused a firearm?
Ok, I’m not getting anywhere with this, and it was a bit foolhardy to ask such a question.
If I overstepped my bounds or offended anyone, I’m sorry.
Mods, please close this thread.
Why go to all of the trouble of building one yourself? Just pick up a copy of Shotgun News and buy the parts. You’ll need to get the internal parts from one dealer and the tube from another. Why? Because it doesn’t matter if you use it; it’s a federal crime to possess the parts to make one.
I’ve heard that books like The Anarchist’s Cookebook and The Poor Man’s James Bond have that sort of information, but don’t do it. Do not even buy the parts. Hell, a 2-litre soft-drink bottle can land you in a federal prison if the BATF thinks you intended to use it as a silencer.
I’m not offended, but I seriously question the intent. Just because I want one. doesn’t exactly stand up in court. . .
Tripler
You want info? I have no official comment.
Well, the problem is that it is illegal, without the proper license, and without being in the proper State, and jurisdiction, etc, etc to possess a silencer. Whether or not it is ever used. Whether or not it is ever installed on a firearm. And, get this, whether or not it even works! Yes, a judge can rule that a completely non-working silencer is an NFA device (National Firearms Act), and thus eligible to send you to 10 years or so to a nice happy place called prison.
So essentially…people are trying to tell you that if your Pop wants to make one without being licensed to do so, he’s on a slow-boat to the Official World O’ Hurt if he gets caught.