Smk Qb78 Deluxe Question......

[PJWmids 35]

does the smk qb78 deluxe use both the 12g co2 cannisters at the same time when inserted in the rifle back to back, or is only one in use and then switch when the one is empty?

[PJWmids 35]

it must only work of the one co2 canister, the other must just be a spare used as to fill out the cylinder.

[jjbull 38]

as far as i know it uses both but you can load an empty and a full one

[TonyHunterSBT 5]

It uses both to fill the tube once the cap is tightened you undo it half a turn t help release the gas to fill the tube, as previously stated u can use one empty one but you get less shots,

 

Cheers

 

Tony

[PJWmids 35]

Does using one full canister instead of two not result in low power then i.e reduced feet per second?

[reaper1064 285]

Hi mate only time mine didn't pierce a bulb was if the cap didn't tighten up enough. they are designed to puncture and use both bulbs, otherwise they would be like the rabbit stopper which only uses one.

[kruby01 114]

they use both mate, i had one for a few weeks and it wouldnt seal at all so i got rid and went back to springs

[barrywhite 282]

co2 work different to air .when the co2 reaches a certain pressure it becomes liquid .this pressure changes at different temperatures .So in the cylinder of co2 on the gun ,the gas is at a certain pressure and the rest of the co2 is liquid .When you shoot the gun the co2 pressure drops ,as the gas is released .Then some co2 liquid turns to gas filling the co2 cylinder of the gun to the pressure it was before you shot the gun .this gives shot to shot consistency with co2 but when the temperature changes from day to day the guns power will vary .unlike pcp s as the air pressure changes so does shot to shot consistence .Think I have got this right and you can understand what I have written .

[secretagentmole 1,701]

In answer to the OP yes the use two bulbs, the way to make them use one bulb is to put a use bulb in with an unused bulb....

[georgenottingham 7]

Like already said above. Most times I only use one, inserting an empty one first. This will not effect power but half the co2 = half the shots per fill. I suggest doing this if you like me like to tinker with their plinker.

 

George

[secretagentmole 1,701]

I have been tinkering with my plinkering, that is the fun of these little rifles, infinite tinker possibility!

[PJWmids 35]

My concern was only using one bulb would give half the power, but this is not the case from the replies, just less shots but the same power. I shot one over my chrono but it was only achieving 6 foot pound at best, they are stated as being 10 foot pound new, but the one I used was an older model. I wondered if the lack of power was because I only used one full bulb and an empty. But this seems not to be the case.

 

My other question is that the 12g co2 bulb had been in my possession for quite a few years as I use them with my pistol but hadn't used it for some number of years. Is it possible for the canister to lose pressure if old. Or should it still work as efficient as a new purchased co2 bulb?

[kruby01 114]

the co2 canister is sealed so it should never lose pressure until it is pierced

[georgenottingham 7]

Its not the co2 that's the problem. Unfortunately these rifle are quite poorley finished. With the right attention you will achieve that 10ft/lb mark and beyond so take caution. When finished properly you'll have a perfect working rifle. Plenty of help available at the "uk chinese airgun forum"

George

[barrywhite 282]

when you got this 6ftlbs .Was the gun a 177 and was it cold when shot .this will also stop you achieving the ADVERTISED 10 ftlbs .As above a badly made gun that will be improved with new seals, polishing,and new parts if required .may just need a polish and a clean and a new hammer spring .