M203 Grenade Launcher rifle

[jimma]

I was bored so I decided to desighn one its kind of like the v3 one but I think it would be more sturdy.

 

[TerranCmdr]

Very cool, I like it.

[ninja master of coffee]

I'm actually thinkig of doing something similar, currently I'm vacilating between an M79 type deal, an underbarrel grenade lancher for my FAMAS or a mock up grenade firing RPG 2. My thinking is that the underbarrel one woudl be simplest but the least interresting, the M79 would be more usable than the RPG but the RPG would probably be the most interresting. What do people think? Also, can anybody think og a way to stock the grenade falling out of the muzzle of the RPG?

 

Cheers

[Village]

Ahh, i get it, all that stuff to keep it from falling out. Anyways, I think I said it before, 40mm piping is not availible at my local hardware stores, I like in america, where everything is in inches. 1.5 OD to 2.0 OD to be specific, where the grenade is about 1.68inches wide I think, so 1.5OD is too small, 2.0 OD is like 1.8 ID I think, too big.

<{POST_SNAPBACK}>

 

doopydoo, uh what am I missing? Aren't these grenades 40mm in diameter? Here in America the 1.5in Schedule 40 PVC pipe is exactly 40mm internal diameter. I have a length right next to me and just measured to confirm. The wall thickness of said pipe is 4mm, so you'll have room to chamfer out some material in case the grenade is a little thicker.

[doopydoo]

40 millimeter = 1.57480315 inches.

http://www.onlineconversion.com/length_common.htm

[doopydoo]

OOH, I see, the piping isn't ACTUALLY 1.5 inches, but for some reason, different! I just checked a pipe website. That's really wierd.

 

Anyways, this ups my hopes. I've also come up with a new design:

 

[zentaurus]

Anyways, this ups my hopes. I've also come up with a new design:

<{POST_SNAPBACK}>

 

may have to do the locking mech in material other than plywood. also think that while the shell button only needs a push a more positive firing sequence can be achieved with a hammer-like mechanism.

[doopydoo]

What do you mean, a more positive firing sequence? And what material should be used? How would I go about getting/creating it?

[doopydoo]

Wahoo, I have the stuff!

 

Listo:

 

ONE ten foot 1.5 inch Schedule 40 PVC Pipe(measured the inside, JUST under 40mm, maybe about 39.75mm, but I dont have calipers)

TWO .5" x 6" x 24" poplar pieces of wood(instead of plywood, I just like this wood better)

TWO hinges of different size, didn't know which one I would need

SOME assorted springs, for trigger spring, and something else I have in mind which will be explained in the next design

ONE nail, for the trigger's axle/pin thingy

 

 

Anyone willing to ship ANY relatively working(at least it shoots, doesn't have to shoot well) M203 nade for $30-35?

[renegadecow]

Which grenade are you planning on using by the way? I just measured the CA ones and they measure 38.90mm on the slug, 41.45mm on the brass case, and 43.00mm on the rim. Which means they won't fit your pipe. Do you have access to 2" pipes? I just finished fabricating my barrel design yesterday, with the fake rifling holding the shell in place by the brass case. Used a 2"~ 50mm (od) pipe and a 1"~ 25mm (od) pipe cut into strips for the rifling. Land to groove depth is approx 2.5mm.

[doopydoo]

Well,... dammit. I could do that hot water thing that someone mentioned. How do you do that? And does anyone else have measurements for any other grenades?

 

I just measured it again, with a different ruler... and it came out to be about 40.75mm this time. Since the widest point was not obvious, I had to measure at a bunch of different areas... I didn't do that last time. Also, in a slightly unrelated topic, about how long is your nade, and what's the capacity?

[renegadecow]

Well,... dammit. I could do that hot water thing that someone mentioned. How do you do that? And does anyone else have measurements for any other grenades?

 

I just measured it again, with a different ruler... and it came out to be about 40.75mm this time. Since the widest point was not obvious, I had to measure at a bunch of different areas... I didn't do that last time. Also, in a slightly unrelated topic, about how long is your nade, and what's the capacity?

<{POST_SNAPBACK}>

 

Just dip whatever part you want to mold in boiling water, then when it gets soft, jam the nade in it. I haven't measured the 120 rounder CA M203, but was told its the same with the 18 rounder (which is what I have), but with a less pointed tip. 95.60mm long.

[doopydoo]

Thanks for the measurement. However, I think a safer alternative would be to sand the inside down slightly, becaus then the outside won't inflate as well. With my break-barrel design, it may not work if the part holding the grenade is bulgy. And I can try both methods, I have 10 feet of pipe.

 

I just talked to someone else, he said his was about 43mm on the rim, 41mm on the casing, and just under 40mm on the slug. I think it was for a Madbull grenade.

[doopydoo]

Update: ordered a Madbull XM108HP and decided I could probably just sand out the inside of the pipe. $73 shipped with tax to california, and judging from how long my UTG MP5 took to get from them, this could be here as early as monday. So yeah... Just some notification that this project has NOT died.

[renegadecow]

Just to ensure that you don't heres a few pics of my latest to keep you motivated. As this is indeed a rifle, I didn't bother making a new thread.

Forergip, butt stock and receiver are made of wood (receiver is hardened and painted to prevent scratching). The barrel, front sight, rear ladder sight, trigger, trigger guard, chamber lock are fabricated from PVC. The whole thing only weighs 1.3kg loaded and is just as intimidating in the battle field as its Japanese branded counterpart, minus the hefty price tag.

[doopydoo]

O.O

 

 

No way mine's turning out that good. You, sir, are the master.

 

Anyways, my nade got here, and I just opened it up, really want to shoot it by hand to test it, and OSHI-

 

"Step 04: Load your grenade into your grenade launcher. Remember, don't use your finger to push the fire button or it will fire immediately and cause damages."

 

Does this mean that I should not shoot it by hand, because it will kill the m203 or are they warning me not to because it'll go off supposedly when I don't want it to, and accidently damage something?

 

Bottom line, is it ok to fire them off by hand?

[Wolfram]

The barrel that I have used in homemade 40mm launchers is the bottom of a golf ball holder. Remember the "shag bag?" or other golfball holders that let you pick up balls by pressing down on them? A golf ball is about 39mm and the holders always run a little big to accomodate the ball. It keeps the 40mm grenade quite snug and is pretty cheap. Good luck with this project.

[newbkiller]

link to this golf ball thing?

[renegadecow]

I think it meant "cause damages" to yourself as firing by hand leaves the possibility of having one of your digits shot. I have a friend whose been using deep fire grenades, fired by hand for quite some time now and haven't heard of them getting damaged.

[doopydoo]

Yup, shot it off by hand, this thing is a BEAST. It actually has recoil, more than my G19, much louder, has lots of visible gas, spread is crazy. I was shot by a CA nade once and could barely feel it, but I can't wait to use this on a cheater and hear the scream.

[doopydoo]

OK, status of project: about 5%. I cut the PVC pipe and sanded the inside for about 3 hours and now its finally got to the point where it slides in and out easily. It's about a 10 inch long barrel. Probably going to keep a bit of spread.

 

Anyways, what should I do next?

[ninja master of coffee]

What firing mechanism did you use renegadecow?

[doopydoo]

 

Look ok?

[renegadecow]

Just a lever. Pushes the valve of the shell as you pull the trigger.

 

Cut out your template on a piece of carboard so you can have a feel of it, and also so that you can make the other half as symetric as possible. OK design, but make the trigger guard slimmer. Use half a circle of pipe for that.

[doopydoo]

I don't want to make it too slim or it will give it a less beefy look, and possibly break if impacted. Also I don't think it will look as cool with a piece of piping for the guard. And right now my design calls for 3 0.5" pieces of wood, so one sheet of cardboard won't do much for telling me if it will be too thick. However, I don't think it will be, I just measured the grip around an M9 and at the widest point it's just about 1.5".

 

Also, what color should I spraypaint the barrel? I have textured black(when you spray it it's kind of like a glock heavyweight frame texture) and glossy olive drab, or should I go to the store and get some glossy black?