I did some investigating and found a page all about these at4's that the military uses but had some questions, it says they are expendable are these the kind where you only shoot them once and then throw them away?? and how can a rocket only be enforced by a fiberglass tube

www.au.af.mil/au/awc/systems/dvic541.htm

The AT4 is a one shot deal.  You pretty much fire it and throw it away.  I've even seen ads in the Shotgun News for the expended tubes.  A fiberglass tube works because the round is a rocket.  A diaphram at the rear of the tube bursts, venting the gas to the rear.  The tube itself is not pressurized.  

There is an AT4 used for training that shoots special 9mm tracer rounds.  If your interested in the AT4, you should check out the SMAW.  It's a reusable weapon, scoped, and has a ballistically matched spotting rifle attached to see exactly where the round will go.

How much do the empty tubes cost out of shotgun news? It would make a cool wall hanger.

but are they legal in CA?

Dats a pretty damn grey area 1911 greg.
Ive seen them for sale in california and stuff, and so im assuming no.
However, Kaliban law does state its illegal to own any device that can fire explosives and wat not (you get the gist) which is why we cant own the 37 mm flare launchers on our AR's. The bofors DID fire an explosive device at one point, but now its just a empty tube with a few switches and pop up sights.
If you ever do decide to buy one, and wanna stay on the safe side, drill two holes (small) through the tube around the triggering mechanism. This would definitely make it inert, and should leave you hassle free should the feds ever kick in your door and accuse u of trying to make an anti armor device. And you really wouldn't notice the holes either.

Honestly though, its just a hunk of tube that looks kinda cool. So if you really into collecting military relics, go ahead and get it. Ive seen them for around 200 bucks and wat not. Id rather buy a brick of ammo..lol

yeah for 200 you might be better off with a couple cases of 223.

i have personally fired both the AT4 and the tainer. all i can say about the real one if FUCKING BOOM!
technically you can reload an AT4 but it's not a thing that can be done in the field. they are pretty much issued as expendable.
the ones that fire the 9mm were designed to fire a tracer. if you are looking to buy one then i would say pass on it. they are very bland to shoot and horribly inaccurate. i think personally if i were looking for a military relic a LAW would be a lot cooler.

ian

The AT4 9mm system was designed for soldiers to learn how the safety and fire system work.  The AT4 is a one shot deal. Armorers can reload them, but they are sent back to the factory.  I shot the AT4 in basic.  Its a cool weapon, but I think the LAW is easier to lug around.  Gunsamerica.com has them for around 200 last I looked.

A funny AT-4 story we were doing a night live fire exercise and someone got the bright idea to put a mount with a night vision scope on it. I think it was a pvs-4 anyway they wanted me to put it on when i got ready to shoot so we go through clearing the buildings and trenches and get to the end and they say there's a vehicle fleeing the AO. so i break out this scope clamp it on and sight on this tank hulk but there is somthing wrong its pointing down to much.sgt is yelling shoot the dam thing im yelling back its f'ed up he yells again shoot so i did it hit the ground right out infront of our position luckily it didnt frag any of us. they yelled at the FO's for calling in fire to close to us. but it was just me and a f'ed up mount.

$200...insanity, a lot of them end up at DRMO so contractors can get them free and sell them for $200. if you buy one youll be pissed that you spent $200 on it.

after its fired im combat, the tube is usually destroyed.

The AT-4 uses a firbeglass tube just to hold the rocket-the motor is an ABOL that is directed out the back of the tube-the tube takes none of the backblast from the motor.