I've got a small hiss coming from my MFR bottle first time noticed. Does it affect the rifle when it's back on? I can't remember! Does it affect the performance? Just waste air?
Is replacing the o ring on the bottle the first port of call? Are these the correct size? ⬇️
015x90 Urethane Bottle O-rings
Hopefully I've got one upstairs but I'll order some anyway. Do I put a bit of silicone grease on it? I can remember to only use a wooden tooth pick to get the o-ring off!
Update. I filled it up to 220 and I couldn't hear the hissing..
I've brought a pellet safe tin, it holds 240 .20 pellets so I cut one of the foam holders and now it holds 200 pellets, I'm right in thinking the MFR should shot 200 pellets without drop off?
I also chrono today and it's only doing 10.8 ftlb and 600 FPS so something's off or I need to turn her up a tad. I'll run some pellets through it Friday to see what happens.
Any advice is welcome. Cheers gents.
So is it leaking with you attach your bottle?
If so, a little leakage is OK, but is should stop when fully attached!
The small O-ring that seal the bottle connection:
BS007--- 3.68 x 1.78mm polyurethane N90
So if you haven't touched the reg core.. then maybe little adjustment to the Hammer Pre-Load...
Good Luck,
Stuart
I noticed my pellets drop off so took the bottle off with the intent of filling it up. When I unscrewed it I heard a small hissing sound coming out the bottle.
I've since filled it up and before I screwed it back on I couldn't hear a hiss at all from the bottle.
I also can't hear anything while it's attached to the MFR.
I'll count my pellets out,keep an eye on the FPS and adjust if needed. It's been unused for a while and I can't remember how it was left it. Reg core is a standard, well kevg tuned.
Thanks as always.
Quote from: MFRGUY on October 13, 2025, 09:39:35 PMI noticed my pellets drop off so took the bottle off with the intent of filling it up. When I unscrewed it I heard a small hissing sound coming out the bottle.
A Bottle leak when not attached is a normal.. this why Theoben used to include a aluminum Cap when you filled and stored it off the Rapid!
Stuart
You know in the back of my mind I was kinda thinking this.
I went through my box of bits today. I've got a few bits I'm going to have to post up as I've forgot what they are, lol..
Few years of not using the Theo and I've forgot some of it nuances found loads of O-rings.. 👍
10.8 ftlbs not far off 11.4 ftlbs,around 5 fps will just need slight adjustment of hammer end cap.you don't need oring on the mfr bottle it's inside the reg.the poly ones are shite,better of with black ni 90 orings.
kevG