Theoben Rapid Forum

Everything Technical About Rapid => Technical => Topic started by: etiam viviens on March 06, 2026, 12:40:24 PM

Title: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 06, 2026, 12:40:24 PM
When looking at the pictures of the custom build rifle by AZ (Allen Zasadney) He always has the quickfill in the bottom of the buddy bottle. Did someone did this to his own rifle and how?

Is is just drilling and tapping in to the bottom, or does one have to make a securing ring on the inside?
The drilling of the hole and threading of that whole should be straight forward so that is not a problem.

I know there are risk to doing it like this but I have seen it done a few times in a very crude way and those are already holding for 10 years plus. And if  Allen Zasadney (he is in high regard?) is doing it, it cannot be all bad or not?
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: angrybear on March 06, 2026, 01:07:24 PM
It's stupid & dangerous, it also invalidates the manufactures safety pressure test.
Any range worth it's salt would ban any rifle with one fitted.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 06, 2026, 01:14:00 PM
That is known, but still AZ and many others are doing it and so far non of the bottles of AZ has failed as far as I know.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: angrybear on March 06, 2026, 01:25:30 PM
I really don't care, I worked with HP gasses for 22 years in the RAF & I've seen what happens when people fuck up & it blows their hand or fingers off.

The taper neck is to spread the load of the valve, a flat bottom is not designed to be drilled, any unauthorised modification is illegal & stupid, end of !

If you want a QF buy/make one for the valve.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 06, 2026, 01:57:02 PM
Its not a ask for permission we are all big boys and I'm aware of the risk, I know the alternatives and have some.
I did ask for some info of people that have done it and there experience, as said before many people have done it like Allen Zasadny. There are some upsides to this way, no modifications to the stock for one, no extension of the bottle to off set the balance of the rifle as second.

That you don't care is ok by me, not here to start an argument or pick a verbal fight on the forum.





Title: Re: Quickfill in the bottom of a buddy bottle
Post by: Ca_Varminter on March 06, 2026, 06:50:43 PM
There a thing that should be left alone....
I have one of his bottles.. just don't talk about it.
He has tested them many times.. or at the owner's request...
No problems that I know of...
I have used Allen's Services since I got my First MKII..
In Fact he was the one that converted It to use the Mark 4 trigger cartridge....
He is a world class Airgun tuner...

Stuart
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: DB.20 on March 06, 2026, 09:34:42 PM
Bought a Rapid from a RFD a few years ago and the buddy bottle base had been drilled, tapped and a pressure gauge fitted!!! Wrapped the gun in a heavy work coat and had a nervous drive home with it in the car boot. Should have asked the RFD to de-pressurise it before buying it in hindsight. De-pressurised it as soon as I got home and ordered a new bottle. Out of curiosity, I removed the gauge and found the threads to be very fine and shallow cut, with no lock not inside the bottle. I've worked on pressurised systems and vessels handling far less than 200 bar where regularly stripped for internal inspection and ultrasound tested. Wouldn't want to have been looking at that pressure gauge when it parted company from the bottle with 200 bar behind it! Still makes me go cold thinking about it and I'm surprised the RFD sold it like that. I did get the Rapid for a bargain price, by the way!
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 07, 2026, 08:10:34 AM
Quote from: Ca_Varminter on March 06, 2026, 06:50:43 PMThere a thing that should be left alone....
I have one of his bottles.. just don't talk about it.
He has tested them many times.. or at the owner's request...
No problems that I know of...
I have used Allen's Services since I got my First MKII..
In Fact he was the one that converted It to use the Mark 4 trigger cartridge....
He is a world class Airgun tuner...

Stuart

How is this constructed, just drilled and tapped and a 1/8 bspp connection screwed in.
Or is there a there a base for this mounted where the forster connection screw in.

Do you have a detailed picture of the connection.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 07, 2026, 06:36:48 PM
I also asked the same thing on "Airgunnation" and they on that thread they send the following pictures.
Apperently AZ use to use Parker connections and now he uses Forster connections directly in the base of the bottle.
all the connection with the exception of T-piece are from AZ tuning.

Some have mounted a T-piece so a fill connection and a gauge could be mounted.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: DB.20 on March 07, 2026, 09:20:30 PM
I'm not a mechanical engineer but IMHO drilling the bottle is going to weaken it and repeated expansion and contraction through pressurisation and de-pressurisation will further weaken the drilled area. I wouldn't want to take the risk.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 10, 2026, 12:14:20 PM
I am or was an Nautical (ships) Engineer, I would not have a problem with it.
Apparently many have done it before and I have not heard of a bottle that suffered damage due to it when pressurized. 
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: Brooksy on March 10, 2026, 05:31:39 PM
In my opinion, it's just like that trend of "chipping" a cars ECU for better performance and fuel economy. If it was any good, the manufacturer would do it.
Title: Re: Quickfill in the bottom of a buddy bottle
Post by: etiam viviens on March 10, 2026, 08:50:56 PM
There was a German car maker that did something to it that was not so legal  :D
I see it more like an improvement that was bought on by the passing of time.