need help with barrel threads not working

[DrScaryGuy]

I can fit my 1/2"-28 9mm silencer on 9mm and 22 pistols, and on AR barrels, and my walther 22 carbine barrel
I can fit my 1/2"-28 22 silencer on my 9mm and 22 pistols, savage 22 rifle, and AR barrels
I CAN'T fit my 22 silener on the walther rifle barrel. It can only get a couple threads in before jamming up.
This makes zero sense to me since the threads are fine for the 9mm silencer, and the 22 silencer that should go on it can go on everything else the 9mm can.

Is this a tolerance stacking issue?
Is anybody around the metro area really really good with threading and willing to help me figure this out?
I might stop up at metrics unlimited because at least one guy there seems pretty pro-gun and he helped me find some replacement bolts for my walther. He could probably at least put a thread gauge on them for me. I can't see how chasing the threads would help since some things fit and only my silencer doesn't.
i'm a little worried that my silencer needs to be worked on...

[oldmann1967]

You might need an adapter for a metric thread. This is for the Walther p22 barrel.

https://shop.waltherarms.com/laser-pk380

[DrScaryGuy]

You might need an adapter for a metric thread. This is for the Walther p22 barrel.

https://shop.waltherarms.com/laser-pk380

nope, i've got 2 p22s and a ppq22. (so yeah i tried that already )
also, i can put a birdcage flash hider and all sorts of 1/2-28 devices on the walther. the more i list it out, the more i feel like it's osmething wrong with the silencer

[jmoser]

Start by measuring bbl thread ODs with calipers. See if the Walther is on the high side of .500"
A thread gauge is next. A common metric 1mm pitch is 25.4 per inch vs 28 so they would look mighty close.

You can `mate` 2 bbl ends as a quick thread pitch check.

M12x1 is too close to tell by eye vs 1/2-28 but would be less than .5" OD

IMHO far more likely that the turned male thread is off vs the tapped female thread.

[DrScaryGuy]

Start by measuring bbl thread ODs with calipers. See if the Walther is on the high side of .500"
A thread gauge is next. A common metric 1mm pitch is 25.4 per inch vs 28 so they would look mighty close.

You can `mate` 2 bbl ends as a quick thread pitch check.

M12x1 is too close to tell by eye vs 1/2-28 but would be less than .5" OD

IMHO far more likely that the turned male thread is off vs the tapped female thread.

Tried that too. a quick check with cheap harbor freight calipers (all i got) shows the OD of the male to be 0.498".
so OD isn't the issue. And as i said, i checked a couple other things at the same threading on the barrel and they went on just fine, as did the silencer in question onto other things... I mean, that's my only 22 silencer, so it hops around from bolt gun to pistol to pistol to AR (22 conversion kit).
That's why I was thinking it could be an issue with tolerances.
watch it turn out to be something stupid.

[Remo]

Has this been figured out yet?

[DrScaryGuy]

Has this been figured out yet?

nope
been busy so i haven't worried too much

[Remo]

nope
been busy so i haven't worried too much

Well dang. It is an interesting problem, was hoping to hear a solution for it.

[PhotoTom]

Sounds like a case of the wrong thread fit class on one or more of the components.

I don't know the specifications, but if the Walther barrel was supposed to be a 2A, but ended-up being a 3A…and the .22 silencer was supposed to be a 2B, but leaned toward being a 3B…that would do it.

[DrScaryGuy]

wut?
i are not machiney