FPE from CR600W

Hi guys what is the average FPE or FPS you get out of a modified cr600? I am trying to work out a plenum size and from my research it is recommended to have 1cc per FPE.

I know co2 gas pressure can change a lot but if I can make the plenum a bit bigger it should hopefully help when the pressure is on the low side.

565fps is with JSB Stratton Jumbos 15.89 grn pellets. These preform the most accurate through the gun.

Billbobnz thanks for that it will help me figure out the plenum I will make it a bit bigger as I like to run heavier pellets.

kruzaroad it is a very nice little gun I was quite surprised at the weight too.

The bottle heater is a good idea not sure what could be use as it will need some kind of thermistor to regulate the heating element but I'm sure someone with knowledge of electronics could easily make an insulated sock with heater using a lithium battery or something, it would be greate for night shooting.

😂 that primitive idea is a pretty good one, I'm not sure how long they last but I know they get pretty warm. I think I'll pick some up from chemist wearhouse and see how they do.

The hand ones go for hours, I'm assuming the body ones do too.
I'd check temps,diff temps for the different applications of them I guess.

10 hours some say and 63 degrees some say too the pressure at that temp are crazy 😂. I will have to definitely do some testing.

Average running pressure on c02 is around 850psi but then due to being sensitive to temperature can go up or down from there.

Worst thing for the little cartridges is that also as you shoot there is a little power curve and rapid firing makes it cool down and drop fps.

I've modified both my cr600 and a crosman 2250 to bulk filled and each shot is so much more consistent + you get about approx 500+ shots from a tank and it cost me under $5 to fill at the local gas supplier.

Spot on. What tank are you using? Also what kind of FPE are you getting? Are you shooting light or heavy pellets?

I have roughly worked out I need a plenum of around 30cc ish if people are only getting around 565fps.

I have one shot at doing the plenum as I will be parting the pressure tube and putting in a regulator so the more feedback I can get on FPE the better the chance of having the correct size plenum, I have read people get a FPS boost from increasing their plenum size so I will go a bit bigger then needed to allow for any increase in FPS from it.

Having the reg should hopefully help with a consistent pressure in the plenum and I'm pretty sure I have found a simple way to maintain a consistent temp of the cylinder so the pressure out put is consistent.