Ok, I know I'm going to get allot of shit for this, and this post may be deleted, but here it goes.
Iíve wanted a M203 for many years now. I know I can buy a Rapid Fire or Shivak receiver and build one in either 37mm or 40mm. I can even buy a LMT. All of these options start at $1500 and go up from there. I've debated the 37mm or 40mm option, 37mm being more realistic for flares, smoke and the occasional bird bomb. The only thing I could fire in the 40mm would be the orange marker rounds, and they aren't cheap. As for any other rounds available for the 40mm, cost prohibitive. In general the M203 is a very expensive toy to purchase and feed, with little practical use. So I asked my self, If the only thing I'm going to do with a M203 is lob inert projectiles down range, what other options are there.
I've researched the airsoft market for some time. There are several manufacturers producing a near identical copy of the M203. Specifically, a company called King Arms. They make a version of the M203 entirely out of aluminum, except for the hand guard. They call it their near metal version. Externally this unit is identical to the real thing, within .020-.030" as checked against M203 prints. You can't tell its a airsoft unless you look down the barrel, which has straight rifling, no twist; or open the barrel to see the pusher which activates the round. Internally, obviously the firing mechanism is completely different. These units work off a 40mm shell which contains a fill and trigger valve. The valve where the prime is, only needs pushed .125-.250" to discharge the round. Therefore the trigger is a simple lever push button. The 40mm round is what makes this interesting. It is a copy of the M381 HE, with a rubber projectile. These rounds are loaded with Green Gas (propane without the odor) or the special stuff you get at hobby stores. Anyway, the propane is cheap. As for lobbing projectiles down range, it does the job. Without riflings, the round tumbles. So, here is my summary of why I went this direction.
I can't be the only one who's done this!
1.Looks and feels like the real thing.
2.Mounts exactly like the original.
3.Marked exactly like the original
4.Cost $100, plus $50 for each round.
5.Rounds are reusable many times, if you don't loose the rubber projectile.
extra rubber projectiles are availabe.
6.Rounds are rebuild able.
7.Rounds are powered by propane.
8.Rounds go 100yds or more, why go any further, harder to find.
9.No registration, itís a toy!
1.Its will always be a toy.
2.Round is not spin stabilized and tumbles.
3.No flares, smoke or bird bombs.
4.No bragging rights.
Here are some pic.
Very nice write-up and photos, but unfortunately, it is off-topic for this forum.