Pluging Up One Co2 Cartrige in a Two Cartrige Gun to Get More Shots ?

[wll2506]

What would happen if I plugged up one Co2 canister (probably the top one), that way the volume from the live canister would stay in the canister tube and the volume of that tube would be less ? Now that probably will not increase velocity but would it give you 3 - 5+ more usable shots ?

Just a thought ?

wll

[csitas]

Hey WLL, your the engineer here, try it , no danger , no loss. 

[Earl]

I hope someone tests this.
I would like to see the results.

[wll2506]

I will drill out a canister on Tue, fill it and go from there ;- ) I'll fill it will epoxy if I can and see what that does ?

wll

[Blowpipe Sam]

I found a piece of aluminum rod that is the same diameter as a 12 gram Co2 cartridge.  I cut it about 3/16” shorter than a cartridge.  I drilled a dimple in one end to keep from blunting the cartridge piercer.  I have used it in my XS60.  My personal XS60 is set up for maximum power and this was not a success.  I’m normally getting about 25 full power “hunting” shots out of this gun with two cartridges.  That dropped to about a dozen with the dummy cartridge which is pretty much what I was getting with one full cartridge and one empty.

[csitas]

I think the results you mentioned are because the volume your playing with is so small , it's almost impossible to see the effects.. Just my thought s.

[AndyKunz]

I opened up a canister so it could breathe freely. I went from 60 shots for two to 25 for one. That little inefficiency is acceptable to me.

Andy

[wll2506]

I opened up a canister so it could breathe freely. I went from 60 shots for two to 25 for one. That little inefficiency is acceptable to me.

Andy

Yes Andy,  I'm getting 25 shots with a single also, and I'm very happy with those results. For a short hunting excursion 25 shots is enough ---- enough to sit in an old abandon barn or someplace else and sit and wait for small pest to land :-)

I'm impressed with the performance of my QB, but I may change the transfer seal to get better air flow and another 25-50 fps depending on your original seal condition.


wll

[jimbo]

Carter, is your xs60 a .177 and what are you getting in fps?

[AndyKunz]

I'm impressed with the performance of my QB, but I may change the transfer seal to get better air flow and another 25-50 fps depending on your original seal condition.

I did a ton of work on my 1085, but I've finally gotten performance that I can be proud of.  It was one heck of a learning experience and I really appreciate all the help I got from the guys here, Ribbonstone in particular.

Andy

[Blowpipe Sam]

Carter, is your xs60 a .177 and what are you getting in fps?

Mine is a .22.  I don’t have a chronograph but Mike sent the test results with it and he indicated that it was making 687 FPS with 14.6 gr H&N FTTs.  I shoot 16-18 grain pellets in mine for less velocity but more fpe.  I have killed several squirrels this year using 18gr Air Arms domed pellets at ranges of almost forty yards.  Mine is flat out the most accurate gun I own.
Oh yeah.  Shooting heavy pellets lowers the shot count even more.

[wll2506]

Carter, is your xs60 a .177 and what are you getting in fps?

Mine is a .22.  I don’t have a chronograph but Mike sent the test results with it and he indicated that it was making 687 FPS with 14.6 gr H&N FTTs.  I shoot 16-18 grain pellets in mine for less velocity but more fpe.  I have killed several squirrels this year using 18gr Air Arms domed pellets at ranges of almost forty yards.  Mine is flat out the most accurate gun I own.
Oh yeah.  Shooting heavy pellets lowers the shot count even more.

For a CO2 gun in 22 shooting those weight pellets you got the pedal to the metal for sure --- that is great velocity ;-)

wll

[wll2506]

Well I'm back - OK, stop your moaning :- ).... here is a pic of a dummy Co2 that has been filled with molten plastic. This unit will take up space so we can see if this idea works or is just a waste of time. I have some shooting to do today with my QB78 that I just changed the breech seal, I will shoot it in a normal way and then with this dummy Co2 to see if that makes a difference .... Until later !



wll

[Ribbonstone]

Volume is small...but you can see the effects.


One co2 QB still runs on it’s bulk fill/PCP valve….doesn’t have a piercing pin.  Will still run from one 12gr. (the front end cap pops it).  So with a live (but un popped) 12gr in first, have taken most of the dead space out of the air tube, and expect that rifle to shoot 25 good shots.


When I swap the used 12gr. For the full one,, it’s exactly the same system, but now the live-12gr has to fill more volume.  Get the same speeds as before, but only 21-22 good shots.

[wll2506]

Volume is small...but you can see the effects.


One co2 QB still runs on it’s bulk fill/PCP valve….doesn’t have a piercing pin.  Will still run from one 12gr. (the front end cap pops it).  So with a live (but un popped) 12gr in first, have taken most of the dead space out of the air tube, and expect that rifle to shoot 25 good shots.


When I swap the used 12gr. For the full one,, it’s exactly the same system, but now the live-12gr has to fill more volume.  Get the same speeds as before, but only 21-22 good shots.

I will gladly take the 3-4 extra good shots !

wll

[Ribbonstone]

Just to be clear.

Hold the co2 rifles to the same velocity limits.  Could shoot more shots, just don’t count the ones that are slower.

It goes back to that often posted co2 pressure graph.  Not quite right for 12gr use, but accurate as an analogy. 

Rather than looking at the pressure to temp…..notice the bottom % of fill numbers and assume a constant temperature.  So pick something like 70F.

co2 by Robert Dean, on Flickr

The level line at 70F is a lot shorter from 50%….much less than ½ the length than if starting from 100%.

[wll2506]

I made a Dummy blank of .736-.737 diameter aluminum and 3.10" long. I did get 4+ more good shots using this method and the Dummy really used up a vast majority of the volume in the compression tube. Being the Dummy length was less then a regular Co2 I could screw the cap way down to the bottom of the threads which also took out some of the tube volume.

My velocity using the 177 cal Monsters in the QB78s was very consistent for 26 shots averaging 604fps (fps as I was getting before, but getting 4+ more consistent shots).  I will take the extra shots gladly for use in a field situation.

More to come I'm sure ;- )

wll

[wll2506]

Just tested with Re-Designed Monsters -- I got 20 shots at 602 fps, had three in the beginning that were in the 575fps area and climbed , and the last two started to dip.

I notice I needed to be sure to give a quarter turn on the front cap before piercing the cartridge to give the valve more freedom to move and better space for the co2 to get to the poppet.

I will shoot and test again tomorrow.

wll

[Nvreloader]

Will

Did you make the dummy cartridge the shape of a regular co2 cylinder,
or use a straight cylinder to the length needed?

I got a 78 coming, I hope............

Thanks,
Don

[Earl]

Someone should print us some plastic "dummy" cartridges.