I'm not familiar with Missouri law, but took a quick look out of curiosity.

This is all I found:
http://www.moga.mo.gov/mostatutes/stathtml/57100000201.html



http://www.moga.mo.gov/mostatutes/stathtml/57100000101.html
Definition of explosive weapon:


Did I miss a statute, or is it in here?  

This would be easier if you pointed us at the offending statute.

ETA:
I missed it on the first pass.
"explosive weapon" includes devices designed or adapted to deliver/shoot the "explosive weapon"?

ETA2:
I'm not sure, but a broad interpretation of this statute could include almost all AR15's and military firearms.  
After all, many of them were designed or adapted to launch rifle grenades, right?

Maybe there's case law limiting it to possession of the explosive along with the launcher?

I too am completely unfamiliar with MO law.

If BATFE is approving forms for grenade launchers in MO, they must think it's legal. If the state of MO hasn't prosecuted anyone for possession of a federally registered grenade launcher, etc. then they must be ok with it also.

From the BATFE Form 4 & Form 1:

Information for the Chief Law Enforcement Officer

This form provides notification of the transferee's intent to acquire and possess a National Firearms Act (NFA) firearm. No action on your part is required. However, should you have information that may disqualify this person from acquiring or possessing a firearm, please contact the NFA Branch at (304) 616-4500 or [email protected]. A "Yes" answer to items 14.a through 14.h or 16.b or 16.c could disqualify a person from acquiring or possessing a firearm. Also, ATF will not approve an application if the transfer or possession of the firearm is in violation of State or local law.

I would try contacting a class 3 dealer in the state, they should know what will be approved or not.

FWIW, all I could find that mentions DD would say it's a no-go
https://www.guntrustlawyer.com/2011/07/missouri-mo-what-nfa-class-3-f.html

Not that I put a whole lot of faith in an internet reference

Destructive Devices are legal in Missouri. There are multiple examples of private ownership. You can consult with Plan B Industries out of Saint Clair, MO. They process civilian transfers for DD and maintain 09/03. The only thing standing in the way of a M203 is a couple hundred bucks and probably a year wait at this point.

Missouri law is largely silent on what would include a federal definition of a "Destructive Device;" similarly, the same exists for AOWs. The MO law is a bit convoluted and it results in confusion. If you look at RSMo. 571.020.1(1) and (2), you would think Explosive Weapons are illegal. Then you might read RSMo. 571.072.1(1), and spit out your beer when you learn "unlawful possession" only occurs when one has an explosive weapon and...

"He or she has pled guilty to or has been convicted of a dangerous felony, as defined in section 556.061, or of an attempt to commit a dangerous felony, or of an offense under the laws of any state or of the United States which, if committed within this state, would be a dangerous felony, or confined therefor in this state or elsewhere during the five-year period immediately preceding the date of such possession; or
(2) He or she is a fugitive from justice, is habitually in an intoxicated or drugged condition, or is currently adjudged mentally incompetent."

I am restricted in the number of characters in a post, but see my post above.  The following was cut from it too:

A cover letter with your application would probably help.  I would not get into the RSMo. crap, rather a straightforward statement that you believe your application is lawful and you understand certain ammunition are in and of themselves DD.  Saying something such as, only lawful ammunition would be utilized in conformance with all local, state, and federal laws.

Anybody have any recent experience with transferring DD in MO. I saw earlier in thread where people have successfully had approved form 1 DD in MO. Anybody do a form 4 DD within last year or so in MO that was approved? Would love to add a M203 to my collection.

Contact Plan B Industries. They are a DD dealer based in MO.

Thanks. Just sent them an email. I forgot they were mentioned earlier in this thread.

Help me understand what are you perceiving as the difference between an approved form 1 vs an approved form 4?  Both will be approved.  NFA branch has started a practice of requesting some sort of "assurance" on what types of ammunition you will be using in the launcher.

No difference but someone had mentioned approved form 1 before so I was looking for more recent info as I know the ATF opinion on things can vary greatly depending on who and when you ask before I start any Form 4. Plan B industries mentioned no issues with approvals. Is ATF inquiring about ammo choices something universal now? What are people saying, "all lawful purposes" :).

Gotcha, I believe the form change after 41F now differentiates among the type of DD.  I simply documented that I was aware that certain ammo were in themselves DD, requiring additional ATF approval and storage requirements.  They approved without any back and forth.

I was asked about ammo on one of my DD transfers. I included a large list provided by grog that pretty much covered everything.

Did they mail you a letter or call? If I end up getting an M203 should I just send a cover letter with my form?

Emailed. Approved a couple days later.

Well placed order for LMT 9inch M203 today . Gots lots of time to collect goodies till this is approved. Definitely getting a 12inch barrel and gotta start getting adapters and chalk rounds.

get a few of these before they are gone $14.99
(for M181/2/3 14.5mm arty trainer projectiles)

12g sold out  


http://damageindustries.co/index.php?route=product/product&path=142_68&product_id=202

Sorry to revive such an old post but update my m203 was approved last week. No issues. Just gotta find time to drive 2 hours to pickup. Now to start collecting parts and ammo.

Cool! 
Don't forget to post pics.

Is the KAC quick detach barrel hanger what I want for mounting? Im planning to mount on my m4 and later get a standalone stock. Is the KAC unit better than the USGI style? Forgive my ignorance on this.

Load up on ammo from Reloadableshells.com

Tri-barrel Cannon and 6 .54 caliber lead balls over 16gr of Bullseye and you're cooking with gas!