Air Gun Home :: View topic - New Disco, 12-15 shots before refill?

dr7197 · Member

Just got my new Disc .22, really like it! VERY accurate! Only thing is I'm getting just 12-15 shots on 1000 psi with 14.5 g pellets. Is this normal? I had expected double that number of rounds before having to refill. Comments? Suggestions? Thanks!

radar · Silver Status Member

You should get at least 20, maybe 25 power shots from 2000 psi down to the red zone on the gauge.
Do you know what your velocity is? Not leaking-hissng air?

Rob

rsterne · Moderator

Assuming you are filling to 2000 psi, you should be getting about 24 shots by the time it drops to 1100-1200 at which point the velocity will be down about 4% below peak.... They typically get about 30 shots within a 10% velocity window....

I wonder if the hammer is somehow sticking at the front and holding the valve open longer.... Something is keeping the valve from closing normally.... unless of course you have increased the hammer spring preload or done other mods.... Was it "new", or just new to you?....

Bob

NZ Shooter · Suspended

Am I missing something ?? dr7197 said he's shooting from 1000 psi.
But the replies are mentioning 2000 psi ......
I'm sure I'm not blind. Mr. Green

rsterne · Moderator

I think by "on 1000 psi" he meant from 2000 down to 1000.... at least that's how I understood it, and that's how a Disco normally operates....

Bob

NZ Shooter · Suspended

Ah, that explains it, I read it the complete opposite Mr. Green

Mind you, what do I know about PCP's ???
:censored:

nothing, clearly Exclamation

dr7197 · Member

SMP · Silver Status Member

Diagnosing a valve hanging open is unfortunately not scientific at all.

The sound can give it away if it's severe enough. Instead of a short crisp pop you might hear a much louder bang with a pronounced duration.

But mainly it's diagnosis based on experience. And Prof Bob has a LOT of experience Smile

If you continue to shoot it there is a good chance everything will work itself in and your shot count will increase.
or
Tear down the hammer and valve assemblies for a quick clean and polish
or
Return it

radar · Silver Status Member

yourdaddyjoe · Supporting Member

The moment you open it, you void the warranty. But in doing so you will learn more about your Disco.

Personally, I'd open her up and polish the heck out of the hammer.
Slip on over to Professor Bob's thread on his 2260. Prime example of hammer pics.
http://www.airgunhome.com/agforum/viewtopic.php?t=8104

The top hammers are stock Disco, I'm presuming after Bob has given them a quick polish. Crosman hammers out of the box are pretty rough. I usually machine my own so I don't have all that galling and they run smoother in the gas tube.

The result will be a much smoother operation and reduced air consumption.

NO PETROLEUM BASED LUBE in or around the air system. It can get explosive!

De-gas/pressurize your Airgun before attempting to work on it.

In order to get the hammer out of the Disco, you will have to remove the breech and barrel.

The trick on a Disco or 2260 is to remove the safety from the trigger group first. You will need a small pick to reach in the trigger group and lift the end of the spring that holds it in.

Remove the stock screw & stock.

Remove the rear trigger screw and breech screw. The end cap holding the hammer spring will pop out and the spring my fly. So be prepared.

Remove the barrel band.

The you can slide the bolt all the way back to get to the .05" hex in the loading port of the breech. Careful, the heads strip easy. I have a straight .05" hex that I insert into the hex and give it a little love tap with a brass hammer before attempting to un-screw. It will tend to loosen it up just a hair so I don't strip the head out.

Watch for the transfer seal under the breech. Should be 2 pieces. one rubber and one steel. Rubber goes against the valve.
(advise 1/4" poly tube tx port mod here)

Once the breech & barrel are off, then slide the hammer all the way back and lift the cocking pin. The hammer will then slide right out.

Polish up the hammer and assembly is the reverse.

Want a hammer spring/power adjuster?
While you have it apart... Get a "hammer spring guide" and take a trip to your local hardware store for a screw that will fit in the end cap just long enough that when you have it tightened down from the rear that you leave at least 1/8" space in the spring area of the cap. If the screw is too long you run the risk of the guide slipping out and binding everything up.

Install the hammer spring first then the guide to the rear. Wait to install the adjusting screw till after assembly.

Then you can per-tension your hammer spring for mo-power! Mr. Green

dr7197 · Member