Commander: Hey Larry, did you bring the 4.2" mortar?
Larry: Naaaaw that was Marty's job.
Marty: No way! My wife would kill me if I put that in the garage! I told you that!
Commander: Dang it! Who's got the 4.2?
Voice from the back: I've got it but I don't have the ammo, that was STEVE.
Commander: Where is Steve?
SILENCE and a quiet cough
Ummmmmm he had a small electrical fire at his place and ummmmmm well the ammo touched off.....
More silence. Commander: Okay who's got the 60mm Mortar? Please don't tell me it was STEVE!!!! Dang it, people! There's a war on! Now what do we do?
I doubt seriously if the 2nd Amendment was meant for the people to keep those terrible implements of war at home. They show up at a central place with their battle rifle and probably a sidearm and ammo for those.
Under those conditions, if I'm in opposition to my government a battle rifle is a fine starting place because with such I can almost by myself stop a division cold (sniper activity) and if I feel the need for bigger stuff, I can collect such from my enemy. If I have a rifle I can get a tank....and so goes the progression to forming my own "militia." If my militia is already formed, I show up with my rifle and my 4.2" mortars will be waiting for me so we can roll right out. But the basis is always the individual infantryman and his personal weapons.
Nobody would _obligate_ militiamen into buying/storing crew-served arms. Obviously they're too expensive/unwieldy/dangerous for most individuals. Key word: MOST.
HOWEVER, if someone DOES have their own mortar/tank/howitzer/bomber/etc., nobody should be complaining if such is needed and he shows up with one!
Obviously, the gov't does its part in ensuring whatever is needed is available ... but that does not automatically preclude someone showing up with more big toys for the party. If you've got the money for one, you've probably got the money - and motivation - to store it appropriately.
Commander: Hey Larry, get the 4.2" mortar out of the armory.
Larry: Ummm...I would but it's broken. The replacement won't be here for another month.
Commander: WHAT! I'd chew you pansies out but that wouldn't give us a working mortar. Dang...
Larry: Ummm...actually, I brought mine. It's in my truck; shall I get it?
Now, at this point, does the Commander chew Larry out for being a crazed dangerous lunatic for owning one, and proceed with no mortar? or does he demand that thing be retrieved on the double, and Larry gets double rations that night?
...and of course, if it's the people vs. the gov't, the gov't sure won't be sharing its heavy/crew arms with their opposition. Remember: the point is to keep the people armed to the point that the rulers are "in awe" thereof. As I've noted elsewhere, the feds may have "won" (Phyrric victory) at Waco and Ruby Ridge, but they sure didn't try that crap again for 15+ years.
That's why it was common for towns to have a central armory: not so the gov't would control those arms, but so people would have a safe place to store dangerous stuff.
A howitzer in my driveway isn't a threat to anyone; it's not going to "go off" accidentally. Neither is Bill Gates's aircraft carrier.