Gunna build a Disco... Something different though. VERY Different!. Got a question though...

[SDale]

Well, I've got a deal goin through this weekend that'll net me enough cash for a Disco and pump. As soon as it gets here, she'll be torn down, tuned a Re-Barreled.

My plan is to up the power as much as possible. I plan on using something like the Boss Valve. A riser breech drilled to accept a custom bolt and a Green Mountain barrel in .38cal and a few other things.

My goal is to end up with something similar to the "Evil Black Rifle" Disco that was posted here a while back that shoots a 125 grain .38cal bullet in the 800FPS range.

The question is: Am I litterally setting my sights too high, or is this at all possible with this platform?

[daveshoot]

Depends on the end game, but wouldn't a .30 cal be nice? Plenty of mass but less weight to move. You could use .30 carbine rounds. Lots of slug choices with nice BCs. 2k psi is not a lot of energy but I am no engineer. I was just kinda surprised to see Quackenbushes in .308, other stuff in Eun Jin 9s and up, and nothing for the .30 carbine bore.

The Koreans are launching 77 gr 9mms with close to 3k psi. I don't guess there are any .30 diabolos so you would have a high drag coefficient.

[SDale]

I actually thought about .30 cal. But I have a surplus of .38/357 bullets.

I also thought of .223 (too much like plain .22 for me!) and .303. Couldn't find a .303 barrel though.


As far as pressures so, I ain't no engineer either  :p  But I thought back to CO2 and how the larger surface area of the .22 is more efficeint than .177 got me thiking that if .22 is good, .25 is better, then .38 would be the cats ass! hahahaha

Anyway... Time for bed. I need to think about this some more.

[Jaymo]

a .303 barrel would be sweet. Then you could use .32 cal lead wadcutters. That would be a little thumper.

[bodiej]

On mythbusters last night, I was amazed to see a homemade cannon shoot a bowling ball 70yds with only a shotgun shell's amount of power.  Not that this expresses anything relating to airguns since air is compressible, but all that with so little power!  How about beefing up the air chamber, as well as the barrel, to be able to contain much more pressure?  Im sure someone will be able to give some advice on the matter.

[SDale]

Thanks for all the input guys!

As far as the air tube,I believe I read somewhere that a Disco tube is good for around 2500PSI. Barrel wise, the barrel I wasn planning on using is a Green Mountian stainless 1.025" Bull Barrel. It should be able to have pressures in excess of what I would be putting through it.

[melloroadman]

Sam my 201 s shots .357 125 grains at 745 fps  if that helps you any . I don't know if you can get enough air to pass through the valve to get as high as you want . That is a short throw on the hammer . But have fun .Marvin

[SDale]

What's the fill pressure on your 201?

Short throw may not be a problem as long as I can get a good dwell time.

[kp4att]

GO AHEAD AND CREATE SOMETHING INTERESTING TO SHOW!!!  GERALD

[melloroadman]

Sam the fill is 3000 psi . I hope you understand I am not saying don't try or it can not be done . I do not have that much experience my self . Just giving you some info . You might take a look at what Roy at Mountain air is doing with his .25 . From what I have seen there are not a lot of barrel choices for longer lengths in the .357 caliber . I tried to get Jack to make me a .357 instead of his .32 and the barrels just are not there . I would think you would need to go at least 26 - 28 inches to get close . I know the .454 he is making me will have a 30 inch barrel on it to get the most out of the air . His .32 have a 26 inch barrel . Here is a link . Good luck Marvin
http://www.southernairgunconversion.com/southernairguns_008.htm

[SDale]

Oh no, I completely understand Marvin. Not a problem at all!

Thanks alot for the info! Those numbers are close to what I was thinking my creation would put out, but I didn't factor in barrel length.

You're also right about barrel selection. The ONLY length I was able to find was 25 inches.

[melloroadman]

My rifle is stock . I have been told my two tuners that they can get another 100 fps out of it and I would have a 3 shot count . The barrel is only 21 inches long . One tuner said he has made longer barrels out of barrel liners but that leaves a lot to be desired at over $ 4.00 a inch and they are thin walled . I might play with mine a little but I am not going to pay $ 150 - 250 for a tune . I will sell the 201's and buy a .32 from Jack after he gets done with my .454 if every thing works out as planed and I do not dought that it will . Then again I might keep the 201 and buy the .32 as well I kind of like the 201 Marvin