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BBMG trouble

Posted: Sun May 02, 2010 7:26 pm
by Lockednloaded
I am about to build my first bbmg, and i need a few tips on the vortex...
I plan on making a burst fire "shotgun" which will consist of a small co-ax feeding a vortex cap bbmg. The co-ax and co2 system will be the easiest part for me, but i need a few tips on the bbmg aspect.
1. for the vortex cap i cannot find a flat pvc cap, will one with a concave end suffice?
2. I am having trouble drilling at angles, I have a c-clamp and a power drill, any tips?
3.In JSR's burst fire bbmg, he uses a tiny cloud chamber, but i do not like this due to reloading issues, but with a large cloud chamber would this concept really work?

Thanks in advance for all your help.

Posted: Sun May 02, 2010 7:49 pm
by Cannoneer
Okay I will try to help as best as I can. 1. in my experience a concave end does not create a problem. 2. whenever I drill at an angle I start by making a vertical pilot hole and then proceed to make the angle. This makes it alot easier to do even without clamps. 3. I'm not sure but I use my vortex cap like a shotgun using a piece of hose as a momentary chamber,but you're idea to use a co-ax is certainly more sophisticated. Good luck.

Posted: Sun May 02, 2010 8:21 pm
by Lockednloaded
thanks cannoneer,
should the pilot hole be smaller than the size i want the final hole to be?

and BTW i can't wait to see your bbmg, post it as soon as you can.

Posted: Sun May 02, 2010 8:45 pm
by Cannoneer
You're welcome. Usually I just get it pretty close to the final diameter then I change the angle of the drill then make it the right size. As far as my BBMG it's nothing special I'l post pictures as soon as I can get my hands on the camera, it's basically a standard vortex cap of pvc construction and it runs on direct feed propane(smells terrible).

Posted: Sun May 02, 2010 8:46 pm
by Marffy
Concave caps will work just fine. As for drilling holes at an angle with the limited tools you have. Make a hole in the cap at an angle with a small drill bit as a guide then go all the way up to the size you need for your barrel. start going straight on for less then or about a millimeter then angle it. good luck :D

Posted: Sun May 02, 2010 8:49 pm
by kydavies
if yu use a smaller vortex cap/chamber yu shouldget more power because the air has less room to expand therefore tere will b a higher pressure inside the cap resulting in more power andpossibly a higher rate of fire. for further info check out PC Guy vortex, i would link it but i dont know how :oops:

Posted: Sun May 02, 2010 9:19 pm
by Lockednloaded
What kind of spread should i be expecting for this project using 100 psi and a break line barrel? At what pressures do you think a gun like this would become no longer airsoft friendly?

Posted: Sun May 02, 2010 9:30 pm
by Marffy
Lockednloaded wrote:What kind of spread should i be expecting for this project using 100 psi and a break line barrel? At what pressures do you think a gun like this would become no longer airsoft friendly?
I would think at 250 psi would make this gun to painful to play with. With a break-line barrel you should be able to keep all the bb's group the size a 34" car tire at 20ft depending on your barrel.
kydavies wrote:i would link it but i dont know how :oops:
copy and paste the link.

Posted: Sun May 02, 2010 9:39 pm
by kydavies
wth minei run it at 40 to 80 psi (depends on what im shootingat) and the spread is a result of you movingthe gun slightly between each bb comming out. rememberi ts not like a shotgun where all the pellets come out at the same time, each bb leaves the barrel seperatly so spread is a result of a combonation of the following: you moving the gun ever so slightly, inconsistancy in the ammunition, each bb is also fired at a slightly different pressure so the trajectory is affected, and also barrel movement ifyou barrel is not firmly attached. look up 2nd 6mm vortex and watch the video of mine and a pic which might give yu some help, sorry about all the spelling errors, im doing this from my ps3 andi have a tiny keyboard. edit: im guessing if your barrel end vortex cap was shaped like a cone you would have a much higher rate of fire because the bbs would hve a greater chanceof entering the barrel at a higher velocity. just a theory. :D

Posted: Sun May 02, 2010 9:40 pm
by Lockednloaded
Marffy wrote:I would think at 250 psi would make this gun to painful to play with
I was thinking that this gun would pack a strong enough punch to break skin at 150 psi because of the extremely high flow. When you put into consideration the minute flow a blow gun has compared to full 1/4" flow i think ill see a considerable power difference

Posted: Sun May 02, 2010 9:52 pm
by kydavies
I would think at 250 psi would make this gun to painful to play with. at 70psi i put 12 0.12gram airsoft bbs through 3 popcans no problem and at 80 psi i put 4 bbs through both side of a tin can so basicly i would go above 50psi ifyour shooting your friends but the moment the piss u off id go to 60 to inflict a wee bit more pain... :twisted:

Posted: Sun May 02, 2010 9:59 pm
by Marffy
I was thinking more along the lines of at least .25 g bb's. I didn't know that he was going to use a ball valve or not and i didn't know if he was a pro airsofter. if he was, he'd probly use .25's for accuracy's sake. (even tho he doesn't plan on using a 6.03 barrel or something.)

Posted: Sun May 02, 2010 10:03 pm
by Lockednloaded
I'm not using a ball valve, I'm using a piston valve which will be more powerful. I will most likely be using .2g bbs due to their price.

Posted: Sun May 02, 2010 10:04 pm
by kydavies
for my barrel i just used some connector rod for toilets (really cheap :D) and a ΒΌ inch BV
im so cheap 8)

Posted: Sun May 02, 2010 10:56 pm
by Marffy
Oh, a piston valve? then 250psi would kill people (not really) but still that would hurt. i'd go to 175 psi max?