Hi,

I have a Beeman RS2 in .22, some CR600 bits that I'm going to set up with a Sodastream bottle and scratch built transfer valve that will be battery heated to 31C, lastly a Crossman barrel (24") with a metal breach and some CroMoly 19mm id tube that would take 3000 psi.  This could become a HPA but most likely a variant on the Sodastream theme.  Done a few CR600 work overs up to 700 fps in .22.  I like to fiddle.

Right now looking for permissions round Auckland for new season bunnies for the table, ones without spotty livers, been a lot of that around the area.  I know some eat them anyway but I guess I'm fussy about it.

Welcome, Sounds like a fun CR600 project. The sodastream bottles are quite heavy, Is there a newer aluminium bottle now?

As mentioned soda stream are very heavy. Find yourself a 9oz paintball tank for co2. easier to find adapters for etc as well..

Hi,

My first go a CR600 worked quite well, went for max volume in the transfer valve and ended up creating a new seat.  Got 700fps with JSB 14.35gr pellets and a slight tightening of the groups as well at the higher power.  The downside was 8-9 shots with liquid present and then a drop off to 15 shots where it was back the standard 480fps. 

Hence my interest in Sodastream.  I have 3 of the new alloy bottles 2x60L (605cc  0.75g tare) and 1x30L (460cc 0.52g tare) so the weight is not bad.  Decision now is infront/behind of the trigger, has a better feel with it behind but that complicates everything relating to the gas path.

I'm a bit concerned that the creation is going to look very like a tactical PCP and that has Police issues.  How do you prove it is CO2 not HPA ?  This whole PCP classification is a clear as mud, the Police can just decide what a dangerous airgun is and that means trouble.  In fact a CR600 at 700fps x 14.35gr is still 15.6fpe, is that really dangerous ?

The gas properties of CO2 are attached, the critical temp is 31C where you will have 1018psi above the line and liquid below.  An unheated CO2 gun at 12C gets about 850 psi or 83% of what it could be heated. 

Fps has many factors, barrel length, gas psi, transfer speed as a product of transfer area and the directness of path.  A real design task, fun all round.

The cr600 is a co2 rifle, and if its running co2 then still a co2 rifle and no police issue.

Doesnt matter if it looks tactical, like a pcp, a machine gun or a bazooka..

 cheers mike

Hi,

Good idea, I'm planning to make a custom transfer valve with an Oring at the front that will cover the sight port.  A section of it will be turned down 5mm for heating coil windings with the wires exiting through the sight port.  I'll have a thermo couple in there too setup for 31C and a LiPi battery pack in the butt.  In front of that the plan is for a permanent plug that has a Sodastream thread and valve actuator.  I'll use the 460cc bottle (about 20 12g powerlettes).  I have a 4k carbon fiber tube as a barrel sheaf.  I'll leave 50mm in front of the valve as a staging tank, I should get enough heat transfer from the alloy transfer valve to to keep this warm enough.  The CR600 barrel is quite nice, got a bit of a choke and likes JSB 5.52s.  The scope will be a Veyron 3-12x44.  I would really prefer a compact fixed 4x32 with zero parallax at 40m.  Light, simple, and cheap, I'm trying to get Vector Optics to build an airgun specific (springer ready) model that has mil dots and a nice cross hair reticle designed for hunting, no luck yet

Must dedicate some bench time for this.......

Very cool.

Tempted to have a play with my Hammerli 850 .177 now... maybe a simple motorcycle heated hand-grip wrap from Aliexpress.

Look forward to learning more about your projects.

Note to all - do not heat CO2 bottles or capsules, 31 degrees celsius sounds like a great performance enhancement but believe me over temperature is bloody dangerous, even left in direct sun they can become a real risk.

Be Safe Mates