Converting the 2240 to a Disco repeating carbine
I got all the parts in today to convert my 2240 HPA Hipac conversion into a Disco carbine.
What I ended up with is:
Bluefork frame
Disco shortened 14″ tube
Disco Boss valve
poly modded 14″ 2240 barrel
TKO LDC
Charles Mellon Power adjuster/stock port
M4 stock
Rim 8 shot mag conversion
Charles Mellon extended bolt
Millet sp2 reddot sight
Pacific Pellet guns fill port and hammer spring
Anthony J aluminum breech and barrel band
Using 25.4 grain JSB Monsters, I shot this 8 shot string, Starting PSI was 2800PSI and ending was 1900PSI which averages 630 FPS and gives me 22.4 FPE.
614
610
627
636
638
640
640
634
I then tightened up the power adjuster screw two more turns which should open the valve a bit more and speed up those first two shots.
This is what it looks like now and what it looked like before I put on the Disco tube
I get almost identical velocity with the Mosters in this carbine and my SS.
Regards,
Roachcreek
All Replies
Viewing 13 replies - 1 through 13 (of 13 total)
I was running a larger diameter tranfer port and modded valve
real short string but didn’t care, I wanted power on level with my AR6 folding stock carbine
never was able to quite get there
Jim,
700 FPS seems to be the limit with this gun, and that is with a heavy spring and 3000PSI fill, and then it kills the bathtub string.
At 675 I get the bathtub back for 8 shots and that is where I will leave it, and that is doing 25 FPE, with 18.1’s it puts it at 770 FPS which is exceeding my SS, but my ss is slow.
Regards,
Roachcreek
Walt,
Thanks Walt, we were all hoping you would show up.
So the short answer is the aluminum ones will come back in your face as may the brass ones without the proper retaining screws.
I sent it to Bryan and Associates for their Boss Disco valve, looking in the bottom frame and bottom valve screw holes, I saw it was brass, I had Ron put it in first due to all the trouble Joe had doing it the first time with leaks.
So being as it is brass, then I need to go get stronger valve retaining screws, from what I have read, I assume I can get those at Ace? Any clues on what to look or ask for?
Rj,
I did fill it and shoot it at 2200 PSI, pretty much the same FPS, just 6 or 7 shots rather than 12.
Riverside,
Yeah I do know I could get a little more, but the shot count will suffer, and I may still do it next week. I have a lot of room left on the poweradjuster, and it is still very easy to cock, where as the spring on the Hipac was a bitch to cock to get the FPS I was getting. And it appears once I replace those screws I can go all the way to 3000PSI instead of 2800 PSI.
BTW, I came up with a fix for the fucked safety on the BlueFork frames, remember how they want to go too far into the fire position and then not fire?
Your going to laugh at this, but after you rebuild your Shoebox, take the leftover used oring, the little white one, it is hard as hell to stretch it over the end of the safety shaft on the right side, but once on it stays put and it will limit the travel of the safety shaft and then the safety works very well. It would work better if you cut a grove for it to sit in, but it seems to stay put without it.
Thanks all for the comments, perhaps I will replace that little red gauge also so I can sleep better at nights.
Regards,
Roachcreek
If that Disco tube is using crosman Disco valve screws and an aluminum valve body I would not use it above 2,000psi.
If that tube is using the fasteners as used in the 1700P and a brass valve body I would us it to 3,000psi.
Tube is not the issue but he valve fastening is. The pic appears to show the philips headed weaker Disco screws.
That is a sick setup roach i’am putting together parts with a local airgunsmith right now for a similar project in 22 cal . This post has me jazzed up big time i can only hope it’s half as sweet as yours . I’am looking at this trigger http://www.cothranmachine.com/images/Trigger_small.JPG and a muzzlemack wire stock 2240 is a great platform and your showing me i’am heading in the right direction .
Hopefully Walter Glover will chime in on this one Roach
seem to recall some time back Walt run a test the results of which he posted to the Yellow on his attempts to destroy a Disco tube by over pressurization.
he did counter bore the retain screw holes in the valve for greater strength but he ran up some pretty crazy pressures
Bottom line is I have never been fearful of a Disco tube letting go
The Colthran tubes are a bit stronger but the standard tube is perfectly safe in the 3K range
one thing you might consider is pulling the gauge and installing a regulator
btw…when I was using that tube on a .22 I was pulling 800FPS+ with the same length barrel using monsters
yours seems to be running a tad slow
Question is, why does it say red?
The 2240 tube with the “weak roll marks” issue is used up to 3000 PSI and the roll marks are supposed to be the issue, the Disco tube has no roll marks. The valve has the three anchoring screws, and the tube is rated far above the 3000 level.
I would like to know why the limit is at 2200 or where the level is.
Is it actually the tube? Many use the 2260 tube to 3000 PSI, and it is believed to be weaker because of the roll stamping, so what is the rating of the DIsco tube and why?
Darren from PacificPelletsguns said there is a safety factor, it is the rating of the tube, which is 4 or 5 to 1,, while the 2260 tube is 3 to 1, what exactly does that mean? Does it mean if you fill to 4 or 5 times the 2200 PSI it will blow up?
And do the 3 screw holes in the tube for the valve make the tube fail at that level of pressure?
On the Hipac I used it to 3000PSI, and was a bit nervous, I gathered that the Disco tube was safer. Should I use the Cothran tube instead?
Regards,
Roachcreek
hey rc try it with a lower fill pressure and let us know how it does im just curious to see how it does
If I’m not mistaken, the Disco gauge shows “RED” starting at 2400psi..I’d be VERY hesitant to go beyond thatbut then again, I am old and a LOT more careful than I was at25 years old !!
I turned the power adjuster in two more turns.
With a 2800 PSI fill, and 25.4 Monsters, I am getting 12 shots starting at 21.5 FPE and topping at 23.7 FPE and ending at shot 12 at 21.5 again, (609FPS to 648FPS and back to 611FPS).
And it is a repeater than weighs 4 lbs. 😎
Now this is a Disco tube and a Disco Boss valve with a PacificPelletguns fill cap and heavy Disco spring they sell, is 2800 PSI too high, the stock Disco is what 2200 PSI?
Regards,
Roachcreek
nice work man! really like it.. fun little gun to tinker with.
now that’s a tight little rig
Viewing 13 replies - 1 through 13 (of 13 total)
- You must be logged in to reply to this topic.
Riverside,
I have opened up the port and poly modded it, and have the Boss Disco, I have no idea what a stock Disco gets with the Monsters.
Regards,
Roachcreek