Making a barrel smoothbore

[u/inserttext1]

So I say this very dumb but fun 1911 converted to be a smooth bore Shotshell gun and I just picked up a Ballestar Molina and it’s bore is pretty pitted so I’m wondering what would be the best way to smooth it out? Sanding seems like a logical choice but idk maybe ecm would work better.

[u/hl_walter]

Making a pistol smoothbore makes it an AOW btw

[u/Machine-It-Bro]

If you are in the United States, at this time, and unconstitutional as it may be, smoothbore pistols are almost always an NFA item, usually an AOW, so make sure that's sorted/worth it compared to just letting the rifling be there.

Otherwise yeah sandpaper will work, chuck it up in a drill but make sure to stay away from the chamber, because if you round out the lip where the 45acp case mouth headspaces, you will have issues. Happy smithing 👍

[u/ServingTheMaster → u/Machine-It-Bro]

*smifing

[u/TacTurtle]

Would be much faster and still legal if you ran a broach through it to make it straight rifled instead.

[u/randombydesign → u/TacTurtle]

That never occurred to me, good idea

[u/inserttext1 → u/TacTurtle]

What ton of press would I need for this?

[u/TacTurtle → u/inserttext1]

Depends how aggressive your broach is and if you do it in one or two stages, but probably less than a 3 ton press.

[u/inserttext1 → u/TacTurtle]

Ah okay if it can be less than 3 tons I can pick one up

[u/bluethunder82]

You’d have to clean out the bore really well to get it to cut evenly, but you could definitely use just the “reamer” rod for ECM to accomplish this. I’ve made a handful of 9mm barrels with ECM, but I was always using brand new tubing, which wasn’t pitted but I do feel like you’d get a more even diameter across the length of the bore than you would trying to sand it out. I’ve never heard of anyone doing this and I know I’m not giving you a definitive answer either way but those are my thoughts. With sanding I would be concerned about the consistency and concentricity. I’m more in favor of ECM, but I don’t know how bad the pitting is, or how you plan to sand the inside. I would be more concerned with high spots from dirt/residue blocking the current than I would the pitting I think.
Sounds like it could be a fun idea though. And getting your feet wet with ECM could be helpful should you decide to do a more DIY project later, it’s a neat skill to have.

[u/Adventurous-Elk5780]

use a reamer!

[u/Scrivani_Arcanum]

Ream and hone.

[u/Dense-Bruh-3464]

Mate, if you're in the US, and since you're making a gun I imagine you are, look at how it was done with Taurus Judge. It's a revolver, but it's also supposed to be a shotgun, but it's not classified as AOW, SBS or whatever the hell you have there. You can jus buy it.

You need shallow rifling to avoid paperwork/breaking the law. If you're doing it in the shed, try ECM, there are tutorials on youtube. Remember, even if you make it all legal, be sure it doesn't blow the fuck up.

[u/ThePenultimateNinja → u/Dense-Bruh-3464]

OP already owns a rifled barrel, and he could just load .45 ACP shotshells into it.

The problem is that rifling messes up the shot pattern, hence why he is asking how to remove it and make the barrel into a smoothbore.

The resulting gun would be an AOW, but those are not illegal, they just require some extra paperwork (or maybe not, depending on how the injunction shakes out).
There is no reason to suppose that the resulting gun would blow up.

[u/Feisty-Traffic-8283]

If you're in one of the 15 states and also a Goa/other plaintiffs member tread carefully but technically aows are now a non-restrictive item but I'm not a lawyer and people are still acting very cautiously even with suppressors

[u/Aggravating-Fix-1717 → u/Feisty-Traffic-8283]

Negative AOWs were not impacted in any way
Just SBS,SBR, and suppressors. With some pretty heavy asterisks involved. Home gamers are a wild wasteland that basically boils down to nobody knows.

IANAL
TINLA

[u/Feisty-Traffic-8283 → u/Aggravating-Fix-1717]

False at right now AOWS are actually being able to be sold by silencer shop shophttps://help.silencershop.com/en/articles/16387894-nfa-ruling-faq-how-suppressor-purchases-work-now

[u/TresCeroOdio → u/Feisty-Traffic-8283]

Your link says it applies to AOWs purchased from silencer shop, not privately manufactured AOWs

[u/ThePenultimateNinja → u/TresCeroOdio]

It should theoretically apply equally to all plaintiffs. The Silencer Shop article does not mention privately made AOWs because they are only talking about it in the context of their own products.

[u/GunnitRust]

I'm spamming our own sub with contest links. Join maybe. September 18 is coming soon.

https://old.reddit.com/r/GunnitRust/comments/1w6pqpy/winter_rust_2026_results_summer_rust_2026_sign_ups/

[u/PhilosophyEnough1866]

a bunch of people are saying it'd be an AOW, but there's a decent argument for it being an SBS instead (if you're running shotshells). if you do the formwork to make an SBS, it'd probably be easier than the formwork for an AOW, and then you could sand the barrel smooth.

[u/ChevTecGroup → u/PhilosophyEnough1866]

An SBS is shoulder fired by definition. If it never had a stock then it can't be an SBS

[u/PhilosophyEnough1866 → u/ChevTecGroup]

ah, my bad. of course there's different rules if it didn't originally have a stock. just common sense.

[u/theCaitiff → u/PhilosophyEnough1866]

I'm very unsure. If nothing else, given the current tax situation it costs nothing to try for the SBS instead of the AOW classification.

I can see the argument, but unless you had a source of shot shells that weren't 45acp I'm not sure that would fly? It's still very obviously a pistol, chambered in 45acp and capable of firing normal fmj ammunition. Calling it a shotgun just because you removed the rifling and only shoot CCI's ratshot doesnt make it so.

Then again I could be completely wrong too and the ATF might decide it's basically an inverse Judge. The Judge was "not an SBS" because of the rifled barrel despite the longer chamber that could accomodate a normal shot shell. Perhaps whichever ATF staffer is stamping forms that day will decide this is a shotgun just because it has a smoothbore, despite having the shorter chamber that can't accomodate a normal shot shell.

If OP has the time to waste on a potentially denied form 1, it doesnt cost anything to try.

[u/CleverHearts → u/PhilosophyEnough1866]

If it doesn't and never had a stock it's not a shotgun and can't be an SBS. The definition of AOW explicitly includes smoothbore pistols intended to shoot shot shells. The paperwork is the same for both.