Disco Carbine

[Trophyhunter49]

  Here is a picture of one that I built with a P-ROD forearm on it.  I used a barrel band to hold it in place by drilling and taping the bottom set screw to 8/32.  If you are using a Disco valve in it ,2500 psi  its not going to shoot worth a flip!! Also I really would not want to put that amount of PSI in the Disco tube!! I have built several PCPs with the Disco tube and the 2260 tubes. The ONLY tube that I would use more than 2000 PSI in would be one of Don Crothran's SS tubes.

[Monkeydad1969]

  Here is a picture of one that I built with a P-ROD forearm on it.  I used a barrel band to hold it in place by drilling and taping the bottom set screw to 8/32.  If you are using a Disco valve in it ,2500 psi  its not going to shoot worth a flip!! Also I really would not want to put that amount of PSI in the Disco tube!! I have built several PCPs with the Disco tube and the 2260 tubes. The ONLY tube that I would use more than 2000 PSI in would be one of Don Crothran's SS tubes.

Hey,

Don't be showing off my carbine...

[BillK]

  Here is a picture of one that I built with a P-ROD forearm on it.  I used a barrel band to hold it in place by drilling and taping the bottom set screw to 8/32.  If you are using a Disco valve in it ,2500 psi  its not going to shoot worth a flip!! Also I really would not want to put that amount of PSI in the Disco tube!! I have built several PCPs with the Disco tube and the 2260 tubes. The ONLY tube that I would use more than 2000 PSI in would be one of Don Crothran's SS tubes.

http://www.magnumairpower.com/pressure-testing.html

The above site seems to indicate the Disco tube is save to appx 3,000+psi while the screws holding the valve are not.  Although with the upgraded screws you can go to 2600psi. 
I just upgraded my Disco to a Prod gauge block and the upgraded screws.  Have not done s shot string yet but it is holding 2600psi and shooting hard as he!!.  Will start another thread when I chronie it.

[beejwest]

I went with 3 10-32 x 1/4 ASTM A574 low head socket cap screws.  I retapped my valve to 10/32.  All the testing by various other members including our Gippeto, indicates this setup leaves a 3-1 safety margin at 2500 psi.  The tube itself is higher than 3-1 even in my understanding.  The screws won't even shear at the 3x pressure, but rather the tube wall starts to fail not from the pressure within the tube, but the force of the screw heads on the wall.  I don't understand why if you have the hammer spring and striker weight, 2500 psi wouldn't work just fine.  We'll find out tomorrow!

[beejwest]

Got it all back together and tuned up again this morning!  Got my P-Rod forend on it with an extra barrel band to hold it.  I had to retap the top screw on the barrel band to 10-32 because I didn't have any factory grub screws for it.  I cut to length the bottom screw so that at the same time it goes tight on the forend, the screw makes contact with the tube, holding everything tight.  I had to add two delrin washers as shims under the forend to get everything to sit tight and snug up as it should.  There was approximately a 1/4" gap before I added the shims.  Feels much better with a forend and I think it looks dang sharp. 

New shot string to handle the 2500 psi fill only took me about 100 shots to get right.  Just needed to up my hammer preload to accomodate the higher fill pressure.  IF I wanted a low power plinker, I'm pretty sure I could get 60 shots around 600fps out of this thing!  But for now it's a hunter through and through.  Shot string as follows:

2400 PSI-1250 PSI
34 shots on the string and within 4%. 
High 940
Low 902
Average 924
ES 38
SD 11

She literallly runs 902-940-902 over 34 shots.  I'm super happy.  Upped the shot count by 10 shots over 400 psi. 

[Trophyhunter49]

  Super looking shooter and good numbers too!

[Monkeydad1969]

Nice, glad you got it where you want it.  I remember my Disco when I first started to mod it.



Now, the Disco is a 200yd, regulated P-Dawg buster (rifle in black Boyd's Pro Varmint stock).

[BillK]

Got it all back together and tuned up again this morning!  Got my P-Rod forend on it with an extra barrel band to hold it.  I had to retap the top screw on the barrel band to 10-32 because I didn't have any factory grub screws for it.  I cut to length the bottom screw so that at the same time it goes tight on the forend, the screw makes contact with the tube, holding everything tight.  I had to add two delrin washers as shims under the forend to get everything to sit tight and snug up as it should.  There was approximately a 1/4" gap before I added the shims.  Feels much better with a forend and I think it looks dang sharp. 

New shot string to handle the 2500 psi fill only took me about 100 shots to get right.  Just needed to up my hammer preload to accomodate the higher fill pressure.  IF I wanted a low power plinker, I'm pretty sure I could get 60 shots around 600fps out of this thing!  But for now it's a hunter through and through.  Shot string as follows:

2400 PSI-1250 PSI
34 shots on the string and within 4%. 
High 940
Low 902
Average 924
ES 38
SD 11

She literallly runs 902-940-902 over 34 shots.  I'm super happy.  Upped the shot count by 10 shots over 400 psi.

[BillK]

Got it all back together and tuned up again this morning!  Got my P-Rod forend on it with an extra barrel band to hold it.  I had to retap the top screw on the barrel band to 10-32 because I didn't have any factory grub screws for it.  I cut to length the bottom screw so that at the same time it goes tight on the forend, the screw makes contact with the tube, holding everything tight.  I had to add two delrin washers as shims under the forend to get everything to sit tight and snug up as it should.  There was approximately a 1/4" gap before I added the shims.  Feels much better with a forend and I think it looks dang sharp. 

New shot string to handle the 2500 psi fill only took me about 100 shots to get right.  Just needed to up my hammer preload to accomodate the higher fill pressure.  IF I wanted a low power plinker, I'm pretty sure I could get 60 shots around 600fps out of this thing!  But for now it's a hunter through and through.  Shot string as follows:

2400 PSI-1250 PSI
34 shots on the string and within 4%. 
High 940
Low 902
Average 924
ES 38
SD 11

She literallly runs 902-940-902 over 34 shots.  I'm super happy.  Upped the shot count by 10 shots over 400 psi.

That's a fine looking and especially good shooting Disco.  You have built a great high  FPS gun w/great shot count.  Congrats!