Bulk filling eliminates the volume occupied by the carts and any piercing assemblies which are removed after conversion. Just eliminating these parts yields an estimated 50% increase in usable volume. In addition, with carts you are stuck with known volumes of CO2, namely 12 gr each. With bulk fill, you can effectively increase the amount of CO2, using improved procedures when charging the rifle.
The bulk conversions I have completed yielded a 100% increase in CO2 capacity, so that is now the goal with every conversion I do. So, if the rifle uses two carts in stock form (24 grams), the goal is to double it, to 48 grams, or more.
The goal is to restore (or exceed) the shot count of the standard rifle, because the conversion to Bulk, almost always involves a modification to the valve, etc, to increase performance (consuming more CO2).
When I was a Paintballer, we used to store our empty CO2 bottles in ice water to ensure a maximum fill. Now, I don't suggest you stick your PCP gun in ice water, but if yours takes bottles then go for it!
Years ago I watched my 20 lb bulk fill tank get refilled at a cylinder service company. The technician hooked my bottle to the "Big Machine" and he bled a whole bunch of CO2 through my tank just to cool it until there was 1/16" of very white frost over the entire bottle. Only then did he close the valve and fill my tank. Without this procedure, you can't fill bulk tanks, or reservoirs on guns.
During winter months I often leave my rifle outside for a few hours to chill it. During the Summer months, the action (minus stock) often sits in my freezer for 5-10 minutes til it's nice and frosty. This allows for better CO2 "transfer" into the reservoir from a room temperature bulk fill tank.
my prob. is that i dont seem to be getting much co2 in the gun.i didnt realy mod the valve just put a discovery front on the stock valve, is this my prob? getting only 4 shots of 530 to 545 fps. i put in a stronger valve spring and tryed a lighter hammer just dont think its filling corectly. do i fill slow? i have plenty of co2 i got a 55 lb. tank to fill smaller tank to save on gas driving 45 min to paint ball shop. Thank You ~ Don S.
Your bulk tank needs to have a siphon (also called a dip) tube installed. The siphon tube goes from the valve all the way near the bottom of the tank. It's purpose is to dispense off the bottom of the tank, where heavier Liquid CO2 is. (Liquid CO2 falls, Gaseous CO2 rises.)
If you are filling from a heavy 55 lb tank standing upright, and the tank doesn't have a siphon tube, you are dispensing only CO2 GAS (from the top of the bulk tank) into the gun. CO2 gas is no longer a compressed liquid... it has already built the pressure needed in the gun, so it won't allow more gas in, hence your limited fills.
CO2 transfers from one vessel to another best when it flows from a Liquid state in one vessel into a vessel where it also meets liquid CO2. Assuming your gun has the bulk fill adapter at the end of the reservoir tube, and that you have a dip tube in the bulk tank, you want to hold the gun muzzle down when filling, so that any residual CO2 in the gun falls to the fill adapter end. In this manner, the liquid flows from the bottom of the Bulk tank into the liquid environment at the fill adapter end of the gun. The watchword is: Think about how to get liquid CO2 to flow to liquid CO2 without meeting any more gaseous CO2 than necessary.
If your bulk tank does NOT have a diptube, you will need to have one installed, or you will need to place it in a couch (to cradle it) upside down, to get the CO2 to fall to the dispensing valve. I suggest this, because a tank this heavy is too awkward to hold upside down by hand without dropping it. And you do NOT want to drop a tank this heavy onto its valve.
Some people build a metal or heavy wooden rig in their garage that allows them to store the tank upside down. While this can be done, you still have the hazard if the rig breaks, dropping the tank on its valve. (Say unguided missile 3-times real fast) I think it's safer just to have a diptube installed so the tank can rest vertically on the floor. This way you can pursue any needed acrobatics with the rifle.
Combine all this with the need to create a cold receiving vessel to create a temperature differential from the bulk fill vessel, discussed before, and you can maximize the movement of liquid CO2 from one to the other.
Oh, I forgot, cock the rifle before loading CO2, to insure that the hammer is not resting on the valve stem, letting gas leak by.
Finally, one of my guns likes to be dry-fired while filling with the muzzle pointed down... This makes sense, because the liquid CO2 is rising up the gun's reservoir, compressing the CO2 gas at the top (just outside the valve head). Firing the gun expells gas from this end, creating more room for liquid CO2 from below. Fire the rifle several times, until you see snow being expelled from the muzzle. This means that the gas is mostly gone and you are shooting some liquid CO2 out through the bore. Time to stop shooting, and close the fill valve on the bulk tank. You're full.
Get a decent quality 5000 gram scale, and weight the rifle empty and then full. The difference in Grams confirms the amount of CO2 transferred. No more guessing.
ill try it,yes it does have the tube in the tank when i fill the smaller paintball tank it gets liquid. i didnt see other posting on the tanks being diff. temp i have both in my garage , so both are cold but same temp. Thank You for your help ~ Don S. P.S. how many shots sould i expect with tis set up. i have a 11 in. tube on the way only 1 in. but hopeing it will help.trying to stay with the pistol look.
But in the Winter, you need to move the bulk fill tank inside. A corner of a warm laundry room is great and won't get the significant other on your butt. Leave the gun outside in the cold. Then bring it inside and go directly to the tank and fill, muzzle down, etc.
and i had to change the fill foster fiting, i used the one that came with discovery and for some reason wasent allowing a full fill. used one from paintball shop it is on the right in pic. big dif. but works great. went from 6 shots to, im on 25 and still getting good crony numbers.
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