If the bore of a suppressor is 3/8", it seems you could call it any caliber less than .375, right? What would you list it as?

ATF won't accept 'MULTI' as a caliber - they want a number, even if you may use the can on a .308, a 9mm, and a .22LR the same day.

As much as I'd wanna F with them. I wouldn't want a reason for a delay.

I'd go with the largest calibre designed to work with it.

techno beat me to it.

.475. Gives you the ability to play with .45 ACP, and everything below.

Wouldn't marking it as suitable for .45 be a deliberate falsehood since the bore is only 3/8" (.375")?

The highest caliber/pressure that it is rated for.

Sub calibers are fine, but you don't want to be running .308 through a .355 can (9mm).

Aye, that's the rub - highest pressure is .308, biggest caliber is 9mm. Can't engrave both . . . .

Well since most pistol/subgun cans are marketed at pistol/subgun calibers and centerfire cans are marketed at rifle calibers the next questions would be:

a) What did you build?
b) What is the intended purpose?
c) What is it capable of?
d) Are you planning on offering it for sale to others who maybe don't have as much brain power as you? (liability, legal, warranty, etc)

Nothing yet. Will efile on a Form 1 tomorrow. 9.6" long carbon steel tube (not a Maglight), carbon steel end cap (3/8" hole), and stainless steel spacer tubes are on order from SDTA. I already have 34.3mm OD galvanized freeze plugs from my car project days. I won't drill any holes until the stamp is in my hands.

Until I get the stamp, it will be a solvent trap; after that, it will be made into a suppressor (NFA firearm that can't propel a projectile).

https://www.youtube.com/watch?x-yt-ts=1422579428&v=YlpSOLcmHEQ&x-yt-cl=85114404

No. It's a one-off not to be sold during my lifetime (Trust-made and Trust-owned).

If you are building to use on a variety of hosts..... Label it .375SF (super fun) and call it good.

Sounds like a cool DIY project, Doc. Let us know how it turns out!

20 mins of work, 6 months of waiting.

:sigh:

if doc e-files, it should only take about a month or so.

doc, just put down the largest caliber (bore size) you plan on using through it and call it good

I turned in a form 1 last December 2014, received the stamp in January 2015, 34 days after submittal. So if the processing is still the way it was a couple of months ago, it shouldn't take to long.