QB78 HPA Conversion, Need a 3000psi Bittle Recommendation Please

[Portland Jon]

I am just starting out converting my QBTuned 78 to HPA and am looking for air cylinder and regulator recommendations please. I'm in the UK but will pay international shipping if I can't find anything in the UK. Can anyone help?

Thanks

Jon

[ribbonstone]

Here are two sites offering airgun type small HPA bottles. JDS only uses ANS type regulators, while ExpertHPA offers a choice...but get the ANS regulator version.

http://jdsairman.com/
http://www.experthpa.com/

IF you intend running the rifle with a remote line to a large sized HPA bottle, then try one of the paintball supply houses...are literally dozens of them on line offering various size tanks.  As you won’t be attaching it to the gun, then I’d go for a larger sized tank.

Am also a believer in lower output pressures...in the 850 psi area.  Guns were made to at this pressure, so from a pressure standpoint 850 psi is 850 psi...be it CO2/air/or aardvark farts.


How are you going to generate the high pressure (3,000 psi) air needed to fill these tanks?

[Portland Jon]

Thanks for the reply, I will have a look at those sites in a minute. I am planning on filling the HPA bottle from my divers air bottle that I can get refilled at one of the local dive shops. I will regulate it down to 850psi then modify the valve to bring the gun down to the UK power limit of 12fpe as it is up to the limit now on CO2.

Thanks again

Jon

[Portland Jon]

I have just had a look at the websites and both look good but I am a little confused as you said to go for the ANS reg. JDS Air Man says to stay away from them.

Jon

[preez]

JDS does NOT use ANS regulators. His regs are built differently. I have used both ANS & JDS but did not test them to decide which ones are better. John I have a spare 13cu bottle. PM me if you're interested.
Chris

[Portland Jon]

Chris

Thanks for the heads up on the regs and the offer of the bottle. How many shots am I likely to get from 13ci as I don't want to be filling it all the time, I'll be running at 12fpe and 850psi? I am really looking for a 22ci bottle but can't find one in Europe and the USA dealers charge crazy shipping fees so I may go for a 48ci bottle and rear mount it then run a hidden remote line into the cut down air tube. That way I can make a nice looking stock and have all the weight at the rear and shorten the barrel into a carbine. I don't suppose anyone knows the weight of a full aluminium 48ci 3000psi bottle do they?

Thanks

Jon

PS - Just found the rich text editor and spotted my spelling mistake in the title, doh!

[preez]

You'll get a lot of shots from 13cu bottle regulated to 850. I am guessing 80-100 shots. I am using it right now on HPA Hammerli 850, it is regulated to 1275 and I get about 50-60 shots. I am switching the bottle to 22cu because I am upping the regulator to 1800psi and want more shots.

Chris

[ribbonstone]

How many shots depends on how fast you have the rifle tuned up to go. Am running 4 different HPA QB's and each one is set up to different power levels but all are running on an 850PSI output 13CI tank.

Generally, you get to use the air from max. fill (3,000 PSI) to something a little over regulator pressure.  So with an 850psi output,  can use from 3,000 to 950-900psi.  IF regged to 1400psi, would be able to use  from 3,000 psi to about 1450-1500 psi.  Would be no problem running right at the edge of 12 foot pounds using 850psi output.

Also realize that regulators tank energy to work, and the only energy is the tank, so then tend to get poor shot counts for the volume.  A well balanced PCP like a .22  AA S200 can easily get 50 consistant 12 foot pound shots from 122CC.  Using a Qb and an HPA bottle can get about 65-70 shots at that same energy level, but it takes 3 times the tank volume (13CI) to do it.

Right now, the .177 is tuned to 650fps/8gr.  and gets about 80 good shots.  The biggest gas hog is a .25 tuned to toss Kodiaks at 680fps, it only gets 35 good shots per fill up.

[Portland Jon]

Wow Chris, great reply, thanks. That's just what I needed to know. 65-70 shots would be ideal so a 13ci cylinder will do the job. I will order a 13ci and a QB79 gas block or make my own gas block as it's fairly easy to make one and use that for the first evaluation model. I really like the idea of rear mounting a larger cylinder and making a short carbine version too so will do that one later.

Thanks again

Jon