New 177 QB 78 very disapointed, only 15 to 20 shots on 2 CO/2 cells

[Ron3]

As said above only 15 to 20 shots on 2  co2 cells. very inaccurate, due to power dropping so fast i would guess. i am very disappointed. after all the good things i have heard about the QB78. anyone have any ideas what the problem could be before i send this gun back to Airgun-Depot.

[Gipper]

Sounds like some sort of leak to me as your shot count should be at least twice that.

Brian

[tennx]

My AR2078 and QB78D both get 25 to 30 good ones on a single.....and both tack drivers...good luck

[Underwhelmed]

Are both cartridges getting properly pierced?

Sounds like the performance of a single cartridge.

[Ron3]

i have tried different cartridges brands, yes they are well pierced.

[floydlong]

Send it back NOW! It's a lemon.

[Ribbonstone]

One of two things...and I'm betting on the first.

#1. It's leaking co2 from somewhere.

Would have to calmly chase down the leak.  Are enough older QB posts on this that you should be able to trace that leak.

#2. It's cranked up in power...or wants to be.

Problem is that sometimes folks crank up their QB by just increasing mainspring tension...which does increase power...but it also DRASTICALLY increases gas use.  Most of that co2 is getting to the party too late to add any fun (pellet isn't gaining speed past some point, but you can keep squirting out co2 long after the pellet has left the barrel).

[Ron3]

gun has never been out of the stock, no mods.new from factory .

[Ribbonstone]

Then fill it with ONE live cartridge and a used one, cock and fire it once, and let it sit over night...try it tomorrow.

That 24grams of co2 (two cartridges) isn't being teleported...it's either leaking out slowly while at rest or being squirted out of the valve at the shot.

[Rayc384]

I read somewhere that the end cap is tightened to pierce the forward cartridge, then loosened 1/2 turn to pressurize the tube.