Semi-Auto Shotgun

iknowmy3tables · Mon Mar 29, 2010 4:01 pm

whitexnightjp wrote:isnt it bad to put C02 in a pvc chamber. (thats wat ive heard, i could be wrong) but yeah i like it. I am also working on airsoft shotgun. What do you use for wadding? and also do you think you could put up some damage shots?

the concern with CO2 and pvc is that if done wrong CO2 and freeze plastic parts causing them to be become brittle and potentially break. However if you heard some guy warning you that it should never be done then they're just safety nazis who don't know what their taking about. The effect usually never that bad

all you have to do is have some volume of some of material that isn't vulnerable to low temperatures to bridge the connection between the regulator and the pvc, in this case it's a length of tubing. this is also known as the expansion volume.

@lockednloaded: for your loading mech you might want to check out this or this

also I'm hoping to see some interesting loading mechs including ones for cartridges in the upcoming Nerf gun competition, in fact if you could figure out a loading mech for 1/2" caliber soon you should enter the competition

Lockednloaded · Mon Mar 29, 2010 4:41 pm

hmmm.... looks pretty easy to pull off, this way my cartridges could be made out of a more available type of pipe. They would also be cheaper and easier to make thanks a bunch.
The only tough job for me will probably be the magazine.
And if my shotgun cartridges get done, I might make one for NERF because i don't have a half decent NERF gun at the moment.

whitexnightjp · Mon Mar 29, 2010 6:03 pm

hey so i have an idea for your shells i came across it in my barn: oar sleaves

Lockednloaded · Mon Mar 29, 2010 7:15 pm

Whitexnightjp: thats a pretty cool find you should try to use some as shells for yourself, but i don't know where i would get them.

And I also have an update!!

I have painted the barrel with a blue/black "urban camo" I hope you like it!
Its a blurry picture due to bad lighting, but you get the idea:

whitexnightjp · Mon Mar 29, 2010 7:52 pm

i think you should be able to buy them at like dickssporting goods or a sports or outdoor store

Lockednloaded · Mon Mar 29, 2010 9:29 pm

I'll check it out, any idea on the OD??
btw do y'all like my new "camo"

Gun Freak · Mon Mar 29, 2010 9:52 pm

It looks good.
I plan on hand painting mine with green themed cammo.

iknowmy3tables · Mon Mar 29, 2010 10:57 pm

nice job on the camo, you should get some sort of 3way valve to pilot the gun instead of the pop off valve, having the input run into the pilot while you vent really wastes air and reduces power, you can reduce affects on power by attaching the input to the chamber which should improve fill rates because sprinkler valve do not fill quickly from the pilot, just add a flow regulating valve or due something to reduce flow if it has trouble seating or more drastically try this

Lockednloaded wrote: The only tough job for me will probably be the magazine.

which part of the magazine?

Spudders · Mon Mar 29, 2010 11:00 pm

20 gauge shotgunshell wads fit perfectly in .5 in pvc thats what i use when i shoot bbs

Lockednloaded · Mon Mar 29, 2010 11:11 pm

nice job on the camo, you should get some sort of 3way valve to pilot the gun instead of the pop off valve, having the input run into the pilot while you vent really wastes air and reduces power, you can reduce affects on power by attaching the input to the chamber which should improve fill rates because sprinkler valve do not fill quickly from the pilot, just add a flow regulating valve or due something to reduce flow if it has trouble seating or more drastically try this

Well if i find a cheap easy 3-way i might get it, but for now i like this set up. The pop-off is used specifically because of this, it open for very little time, and since i'm using it 5 psi below its popping pressure all you have todo is barely touch it to pilot, and once the pressure drops, the pop-off becomes harder to pull, and the spring pulls it closed again.

which part of the magazine?

The part that holds the ammo, i might just make it out of wood though

whitexnightjp · Tue Mar 30, 2010 11:34 am

I'll check it out, any idea on the OD??

im gonna sound like an idiot and ask whats an OD?

Gun Freak · Tue Mar 30, 2010 12:32 pm

Outer diameter.

LnL do you say its semi auto because its hooked up to the Co2 or do you get more than one shot per fill in your pvc tank?

iknowmy3tables · Tue Mar 30, 2010 1:18 pm

Lockednloaded wrote:
nice job on the camo, you should get some sort of 3way valve to pilot the gun instead of the pop off valve, having the input run into the pilot while you vent really wastes air and reduces power, you can reduce affects on power by attaching the input to the chamber which should improve fill rates because sprinkler valve do not fill quickly from the pilot, just add a flow regulating valve or due something to reduce flow if it has trouble seating or more drastically try this
Well if i find a cheap easy 3-way i might get it, but for now i like this set up. The pop-off is used specifically because of this, it open for very little time, and since i'm using it 5 psi below its popping pressure all you have todo is barely touch it to pilot, and once the pressure drops, the pop-off becomes harder to pull, and the spring pulls it closed again.

a cheap and easy 3-way like this, I admit though the 3way blowgun does have have pretty bad flow and I'm not sure if the performance would improve because I don't know how well your system works and I also appreciate the fast trigger
however I would still insist that you move the input to the chamber because of the slow flow through the diaphragm.

Lockednloaded · Tue Mar 30, 2010 4:49 pm

LnL do you say its semi auto because its hooked up to the Co2 or do you get more than one shot per fill in your pvc tank?

in the current setup I can get two shots, but I can get nearly six with a larger 3" chamber

however I would still insist that you move the input to the chamber because of the slow flow through the diaphragm.

well my ultimate goal for this valve will be a semi auto inline piston by replacing the diaphragm with a piston which should optamize preformance to it's all time best.

a cheap and easy 3-way like this, I admit though the 3way blowgun does have have pretty bad flow and I'm not sure if the performance would improve because I don't know how well your system works and I also appreciate the fast trigger

like I said, I will try to look into this especially your blowgun mod, but ATM the popoff I have has way better flow than any other pilot so far, but again I'll experement