how many shots out of disco .177?

[venxxxxx]

Hi guys,
Got my disco for a few days and wondering how many shots I should get out of 2k psi filled disco? So far I only get about 18 before it goes to 1k psi. Is that normal?

[Ribbonstone]

Hard to judge without knowing the power produced in those 18 shots, but it does seem like too few for that much air.

Have had anything done to it?  Power adjuster, spring change, etc?...or is it "out the box"?

[venxxxxx]

Nothing done to it as far as I know of...got it slightly used but no marks of it tampered with. I do notice a lot of air gushing out from the breech and trigger when fired.
Im ordering a .22 barrel and bolt to swap out. Maybe that might be better than .177

[Ribbonstone]

Shouldn't be leaking air from the breech and trigger area, that's where at least some of your air is being used.  Have to suspect the bolt probe o-ring and the transfer port as the likely leak sources.

[venxxxxx]

Just retest it. Pumped to slightly over 2k I got 26 shots til 1k. I'm going to fill it again and leave overnight to see if any leakage.

[Ribbonstone]

OK..but was talking about the air "extra" air squirting out at the shot.   Should be a little 0-ring on the end (probe) of the bolt...if it's chewed up or missing, will squirt air at each shot.

Guess the easiest way to check the number of "good" shots without a chronograph would be to set a target out at your normal max. range for practice and shoot.  Keep track of each pellet's hit, and once it starts consistently hitting low, call it the end of the "good" shots.  May find that your point of impact climbs a bit at first as well.  Aren't talking a lot of shift at short range.

Will find a picture.

OK..different gun...and i do have a chronograph....but shot this row of targets as i was getting velocity readings.  Can see how it started a little slow, leveled off to a "sweet spot", and then declined in velocity.  Pellet impact wasn't a whole lot changed, but enough to measure.

[venxxxxx]

Ahh, gotcha... I'll get a bench and try that ...so far I put it on a tripod and a towel to shoot, my hand shakes a bit a each different shot so no accurate measurements thus far. Thanks for your input, i will shoot again tomorrow and post results.

[jrinehart]

i also get about 18 to 20 good shots in both .177 and .22   I think at normal power setting that what they get.

[Ribbonstone]

Can print free graph paper from on-line sites, which makes it easier to keep track. Some guns do tend to wander their point of impact a bit, which complicates matters a bit.

One way to look at shot count is to think in terms of the target you are shooting...if plinking bottle caps 20 yards, then could keep on shooting until the rifle showed 1/2 a bottle cap of drop (which would be a lot of shots).

[jimmie lee]

I got a lot more shots than that w/ .22 disco stock no mods. Now have double tube and can get 100 shots from 2000-800 psi. Not all those are in the "sweet spot". I now fill to 1750 and shoot to 1200 for 40-41 shots in the sweet...there is just too much deviation with my disco above 1750 psi or below 1200 psi hence, "sweet spot".