Tuning Any tips for tethering an RTI Prophet?

Haha, I do have one sitting on my bench, that is why I'm so motivated to get this working 😉. I'm in the accuracy camp as well and I'm hoping to get it working with the prophet so I can avoid all the awkward hex key tweaks and reg settling between strings, pellets and barrel changes.

PXL_20210117_204845296.1611079097.jpg


The main problem is that the any reg adjustment will end up slowly filling or emptying the bottle and the manual says to never fill the bottle from the external reg port...








 
Well I can tell you that early RTI’s had a pin valve on the reg. You could take the bottle off without degassing. If you look in the front of your gun with the bottle off, you might see the little nub that depresses the pin valve on a reg. My Priest ll has it. Maybe RTI got so caught up in building a better reg that they abandoned the pin valve. Here are a couple regs I used on my gun and even the one RTI built for me has a pin valve.

Thanks for the pic. The first time I took the bottle off I had hoped that the nub inside the gun was the pin valve but it's just there to depress one in the reg if it has it. 

I still haven't had a reply from RTI so I'll either have to take the plenum apart to take a look for a failed check valve or attempt to plug the bottle hole with a G1/2-14 bolt. 
 
The mystery has been solved, I got a response from RTI:

We stopped putting in the anti valve not so long ago (part number 56
on the exploded view):
https://www.rtiarms.eu/assets/docs/Prophet%20exploded%20view.PDF

because we detected better consistency of shots when valve is removed.
But in the mean while we looked for solution and we are now putting a
valve on the other side of the pipe (#37) which does not affect the
consistency.

The serial number range for my gun had neither the old or the new valve so there is nothing restricting air flow from the rear port.

They are mailing me the part. Thanks everyone for your tips. 
 
Hi,
Just registered my membership to the forum because of this tethering discussion.
My Prophet is always tethered and I love it.
The UK only allows 12 ft.lb and I had various problems with various regulators, some RTI versions, some other manufacturers.
Sheer frustration led me to the Huma external regulator that affixes to my 7 litre bottle.
I have blown up regulators by filling from the rear nipple, but as soon as I took off the bottle and plugged the front of the block with a sealed o ringed nut, eureka, wow, no regulator creep , accuracy that I had never experienced with any other gun.
I have the .22 long barrel version that won the US 2019 benchrest.
So, the Huma reg is flexible from 125 to about 200 bar and you can dial it up and down as you want.
Best thing I ever did with the gun.
I shoot between 400 and 500 pellets every time I go to the range, but remember I am sub 12lbs and I can put five pellets within an 8mm diameter at 70 yards outdoors with a slight wind using AirArms 16 grain.
Hope this has been of interest to you guys .
I am disappointed to discover that Prophet 2 cannot be tethered via a rear nipple, its now a pressure gauge.
The Priest will tether also but has the straight pull cocking lever.
I sit hours behind my Prophet, and I have several other guns, but not one of them gives me the sheer pleasure that the consistency and accuracy of the Prophet gives me tethered with the Huma reg.
Try it folks, you may just transform your gun at the bench.