are all 12g co2 capsules the same?

[derekm]

All CO2 obeys Boyles' and Charles' laws of pressure volume & temperature.

Maybe the differences you found were due to the temperature of the gun dropping during the tests as more shots were fired.

[Hollowpoint]

The differences i noticed where an average over a whole capsule. I did leave a good while between capsules so maybe air temperature was a factor. Having said that the umarex capsules where down about 1ftlbs on the ASG capsules. Perhaps they where under filled

[derekm]

At a given temperature, as long as you have some liquid in the cartridge, the pressures should be the same. The quantity of liquid is immaterial.
Over 3 cartridges, say 240 shots in a session, the gun will cool considerably, lowering the pressure.

[hwtyger]

Umarex have different length head iirc. Longer?
I've had several problems with them piercing too soon (before the cap sealed) with my tau 7 Junior..
Crosman for me, NEVER had any problem with those..
I've seen walthers as well, even 'maintenance caps'(with oil probably)

[Hollowpoint]

At a given temperature, as long as you have some liquid in the cartridge, the pressures should be the same. The quantity of liquid is immaterial.
Over 3 cartridges, say 240 shots in a session, the gun will cool considerably, lowering the pressure.

While I have no doubt that what you say is scientificly correct. I know for a fact that the 20th shot is always lower power than the 1st even if you leave the gun to warm for a lenght of time.

[evert]

I'm bringing this thread back from the dead to see if anyone knows anything more about this topic?
Has there ever been done any tests?

[Cannon Fodder]

Some have oil mixed in (the crosmans from memory) and I know stock class paintball players in the states avoid crosmans ones as the foil that seals them is thicker than other brands so dull pierce pins quicker (but then they'll get through a lot of them). Personally I'd go for whatever is cheapest.

[evert]

Personally I'd go for whatever is cheapest.

Thats what I've always done. I keep my Co2 guns well oiled, so the oil cartridges are not needed.
But some people are raving about umarex Co2, is there any truth in that? Are they cleaner? do they contain more Co2?

[WesseH]

All the types I've used, including Milbro, Crossman, Umarex and what I think it classed as JSR's own ones did absolutely fine for me.
I used the Walther oiled ones once as well, but as others have said, it is much cheaper to just dob a drop of pellgun oil or similar on the head before inserting (afterwards would be absolutely futile...!).

I do have to add, it never mattered much for me as I only used CO2 for speed shooting reactive targets and never in official competition, so if my pellets started dropping off mid session they either still hit the plates or I just swapped CO2 and started again.

[evert]

I've been thinking about a jig to pierce and empty capsules, with a disposable filter that captures any dirt that is blown through.

[Rickstar007]

In my experience, you want the co2 cannister to be a nice comfortable fit in and out to prevent it from getting stuck. I know some people often use grease on each cannister but I find that continual use of grease will result in mess and everything conjuling up in there, so find a brand which works best and fits for your gun!

[ibzt]

I've tried lots of different ones and never noticed a difference performance or power wise