Reflex moderator unscrewing itself

The Mole

Well-Known Member
I've just bought myself a Mannlicher Scout with T8 mod, and find that the mod is unscrewing itself after only a few shots on the range. I don't have this problem with my other rifle - any thoughts out there?


Well-Known Member
my uncle and i had this sort of problem with our T8's we found it was to much oil on the rifle thread and with the rifles being new did not help once they were used a little all the newness went and the mod started to grip you can also check to see if the plastic end hole is not to large for the barrel as that helps to prevent movement when fired hope this helps

The Mole

Well-Known Member
Thanks stone - I'll persevere. The plastic collet for the bottom end of the mod does seem to be the right size for the barrel.


Well-Known Member
Hi, I've had four or five t8's over the years on different rifles and calibres. All of which became loose after a few shots. I ended up changing to a jet z. These are brilliant and never come loose, dont know why reflex should have this problem.


Well-Known Member
Hi all.
Ive never experienced this problem with any of my T8s over the years. I dont use oil on the threads anyway just apply a little molybdinum based grease, Just enough to lubricate & protect the threads. Screw the moderator down & just nip it up. Check the bush at the rear of the moderator is not too tight on the barrel. You should not feel any resistence at all as the moderator is screwed down. If there is then open the bush up slightly. Ive always left a couple of thou" clearence between bush & barrel, The bush is there to stop lateral movement at the rear of the moderator if knocked. A couple of thou" clearence wont have any affect on this & also stops the blueing wearing off the barrel.


Well-Known Member
I have just had the same problem today, I would like to have been zeroed in less than 15 rounds... & I'm still not sure.
The gunsmith made me a brass bushing, which he fitted an O-ring inside, this has fallen out with being taken on & off everytime I use it, & as far as I can tell, this is the reason I had difficulty zeroing.
I will dig out the superglue & put another one inside.


Well-Known Member
Suspect its just to do with different barrel vibration patterns between the rifles. Sounds very much like the question why multichokes in some shotguns shoot loose and others actually tighten up through shooting.

Monkey Spanker

Well-Known Member
Beowulf said:
Forgive my ignorance on this subject, but wouldn't applying a little 'loctite' to the threads help?
It would indeed help. However, the moderator should be removed for storage after every time it is used as it contains moisture and corrosive vapours which will destroy your barrel if left on. A bit more elbow grease whilst fitting will probably help though, and keep the threads almost dry.


Well-Known Member
Biggest problem on over barrel mods comes from the little plastic bushing.
If in doubt, just toss it into the bin, much better than a bad fitting bush.
I run all my moderators with a huge gap ( 0.3 - 2mm) in the bush.

I would try two things,
1) remove plastic bush and mark the shoulder of the thread on the rifle with a permanet marker. Screw the moderator on and off two three times hard against the shoulder. Check if the marker ink is scratched or removed evenly on the complete surface of the shoulder. If it seems to only touch on one side, your threading job might be dicky and needs to be redone.
If it seems even,
2) try shooting without the bush. But tighten well by hand and check after each shot at the beggining.

If you have an improvement, just open the diameter of the plastic bush by about 0.5mm and put it back.

Chris Rob

Well-Known Member
I have a T4 on my Tikka .22-250 & had the bush machined to give a small clearance & only use a smear of grease on the threads & its not come loose in over a year of use.