Co2 Bulkfill

[tinbum]

I have a Co2 pistol with Bulkfill capability and a Co2 bottle from home brewing that screws directly into the pistol, I tried filling it but the power and shot count were very low. I have since learnt that the tank should be inverted during fillng to allow liquid co2 into the pistol, but that sounds kinda scary! With no gauge etc is it possible to overfill? Any hints tips or advice?

[Hsing-ee]

When I bought my Brno from Mays gun shop, they recommended I put the pistol in the freezer (!) for a while before bulk filling it - put it in a cloth and then a plastic bag first. The reason is the storage reservoir needs to be cold to get a good charge in there. Then I found out that just filling it a bit and then firing ten shots rapidly would do the same thing. Also, yes you do have to let the liquid co2 flow into the reservoir. You have to let the pistol warm to room temperature after, but it doesnt take long.

So, fill it a little, then dry-fire ten shots, then fill it properly. You can't over-fill with CO2 as far as I know, it runs much much less pressure than HPA as it liquefies at a much lower temperature (CO2 molecules like sticking to eachother more than the mix of gasses in air, and is therefore more viscous). It is a pretty safe propellant, and you cannot have the kind of catastrophic explosions that can happen with HPA. The downside is if you fire alot of rounds rapidly on a cold day, not only will the power be very much lower than if it was powered by HPA, but there is a risk of finely engineered parts getting supercooled and jamming. My brief relationship with a QB78 included a jammed bolt during an accuracy testing day in very cold weather, and that rifle had been smoothed out by an expert.

Have fun!

[tinbum]

When I bought my Brno from Mays gun shop, they recommended I put the pistol in the freezer (!) for a while before bulk filling it - put it in a cloth and then a plastic bag first. The reason is the storage reservoir needs to be cold to get a good charge in there. Then I found out that just filling it a bit and then firing ten shots rapidly would do the same thing. Also, yes you do have to let the liquid co2 flow into the reservoir. You have to let the pistol warm to room temperature after, but it doesnt take long.

So, fill it a little, then dry-fire ten shots, then fill it properly. You can't over-fill with CO2 as far as I know, it runs much much less pressure than HPA as it liquefies at a much lower temperature (CO2 molecules like sticking to eachother more than the mix of gasses in air, and is therefore more viscous). It is a pretty safe propellant, and you cannot have the kind of catastrophic explosions that can happen with HPA. The downside is if you fire alot of rounds rapidly on a cold day, not only will the power be very much lower than if it was powered by HPA, but there is a risk of finely engineered parts getting supercooled and jamming. My brief relationship with a QB78 included a jammed bolt during an accuracy testing day in very cold weather, and that rifle had been smoothed out by an expert.

Have fun!

Cheers Al, it's a Brno I'm using. I think I'll have to eat some ice cream to create room..

[Hsing-ee]

I didn't follow the freezer advice because I was a bit concerned about condensation and rust, but if you make sure you oily rag the pistol it should be OK. Ice-cream is top stuff, I like the Carte d'Or stuff, especially the Rum and Raisin - do your local smugglers/pirates eat this? And of course the tubs are excellent for all kinds of DIY storage and paint mixing purposes....

The Brno B-96 is one of the best airguns ever! You must try machining up a 10, 12 or 20 shot mag, it will be like a miniature Hotchkiss machinegun.

[tinbum]

I didn't follow the freezer advice because I was a bit concerned about condensation and rust, but if you make sure you oily rag the pistol it should be OK. Ice-cream is top stuff, I like the Carte d'Or stuff, especially the Rum and Raisin - do your local smugglers/pirates eat this? And of course the tubs are excellent for all kinds of DIY storage and paint mixing purposes....

The Brno B-96 is one of the best airguns ever! You must try machining up a 10, 12 or 20 shot mag, it will be like a miniature Hotchkiss machinegun.

Confession time! It's Black cherry flavour frozen yoghurt! I've never been quite the same since I started using .177, I fear a pair of Espadrilles looming on the horizon for the summer.

My empty pot is full of frozen chillies from last years crop, this never ceases to annoy my wife who grabs it with a look of hope every single time.

[hwtyger]

You cán overfill CO2. Its filled by weight though so simply check max filled weight. Its mentioned on the cilinder. If its a non-detachable cilinder, it may be in the manual. But in case of a grip reservoir, it wont take much more CO2 than the 12gr bulb gives it. If overfilled, you will hear it during first shots. You can also bleed it on some guns.
Yes if yr bulkcilinder doesnt have a syphontube, it needs to be inverted to fill.
Imo, bulkfill with a gun with non-detachable cilinder is pretty much worthless.
Even if you dó dryfire shots, to get a max fill is terrible. Its just not as good as freezing a cilinder.
If you cán just use 12gr bulbs (or if you have detachable cilinder, use a freezer)

DONT put the whole pistol in the freezer!! If you do nót have detachable cilinder, use bulbs.