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Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Fri Oct 30, 2020 9:01 pm
by Nevergiveup
I’m finally getting around to purchasing my first PCP Match pistol.

I will use a SCUBA tank to fill it. It’s cheap and safe staying with a 200 BAR tank.

PCP Match Pistols come with an adaptor that can connect the pistol’s cylinder to the SCUBA Tank’s DIN fitting. Is the tread on the pistol’s adapter made for a DIN 200 or 300 BAR tank?

Assuming I can just screw the adapter to the SCUBA Tank’s 200 BAR DIN fitting, the next step is to attach the pistol’s cylinder to the adapter by screwing it in place. Next, I slowly turn the valve on the SCUBA tank watching the pistol’s cylinder’s pressure gauge, closing the valve when the pistol’s cylinder gauge shows full.

The next and last step is to remove the cylinder from the adapter. Is there a bleeder valve on a standard SCUBA tank? Or do I just unscrew the cylinder from the adapter and get a puff of air?

Is it this simple or am I’m missing something? I don’t want to get a SCUBA tank with a DIN fitting and find out I’m missing some adapter. I know there are special attachments like pressure gauges and quick change fitting, but I think (hope) I don’t need any of that with a 200 bar Scuba Tank and a 200 bar Pistol cylinder. Looking for simple and cheap.

Thanks!!

Re: Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Fri Oct 30, 2020 9:50 pm
by Gwhite
If you get a pistol with 200 bar cylinders, the adapter will be 200 bar as well. SCUBA valves do not come with bleeder valves. If you want to avoid wear on the cylinder threads by using a bleed valve, you will need to invest in a more complex fill system. These guys sell every sort of fill hardware you can imagine, and it's very high quality:

https://www.bestfittings.co.uk/

A couple of things to watch out for:

If you buy a SCUBA tank with a DIN valve, 200 bar versions are rare. Divers want the extra air, and most modern tanks are rated for the higher pressure. There are various adapters to allow using a 200 bar fill adapter in a 300 bar DIN valve.

A lot of dive shops will ignore instructions to fill the SCUBA tank to 200 bar, and will give you more. I regularly get tanks back that are filled to 230 bar. That's OK if you are careful, but in theory, you could over pressure your cylinders.

Re: Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Sat Oct 31, 2020 3:05 pm
by David M
200 bar DIN connections have 5 threads and 300 bar DIN connections have 7 threads.

The deeper 300 bar DIN valve is intended to prevent the shorter 200 bar DIN conenction from seating to prevent a 200 bar tank not rated for 300 bar pressures from being connected to a 300 bar bottle.

A 300 bar pistol adaptor will screw into a 200 bar bottle, but a 200bar pistol adaptor is too short for a 300 bar bottle
din.jpg
din.jpg (19.49 KiB) Viewed 1562 times
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Make sure that you get a 200 bar tank fitting.
If only a 300bar fitting is available, then get a machine shop to shorten the bottle fitting by 2 threads or make a insert to shallow the threads.

Re: Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Sat Oct 31, 2020 4:31 pm
by marky-d
I made one of these adapters so I could use my 200 bar fitting on my 300 valves:
http://www.gasbottlesdirect.com/product ... 00-bar/101

marky-d

Re: Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Sat Oct 31, 2020 8:27 pm
by KDZ
Hi all this is my first post here.

I normally shoot a different discipline (20M air rifle benchrest), and have a large 300 bar SCBA tank used to fill the BR guns. The BR guns have a Foster quick-connect, which is very convenient.

Recently I've ventured into 10M air pistol (I know...Yaweh help), and the air cylinder adapter that came with my FWB P44 has DIN 200 bar threads, so it doesn't mate with a 300 bar tank. The tank I bought has a slow-fill hose and a bleed valve to degas the cable / regulator after a fill. The fill is slow and helps prevent unintentional overfills. Here:

http://www.airtanksforsale.com/GreatWhite/

(There are cheaper ones available, eg Mac1 airguns Tim McMurray, but they are quick fill)

Anyway there is an adapter that threads onto air pistol 200 DIN and has a male Foster nipple. I have been using this for AP and it is quick and easy. Here is the adapter:

https://www.pyramydair.com/s/a/Air_Vent ... nnect/5358

OK that was my good deed for the day. Now can someone tell me an easy way to hold still while pulling the AP trigger?

Re: Using a SCUBA Tank to fill A PCP Match Pistol

Posted: Sun Nov 01, 2020 11:36 am
by Nevergiveup
Thank you for all your responses.

I have a much better idea of the specifics of what I need.