Screw threads in Eclair ACL

[Gregg MacPherson]

Does anyone know if the screw threads in an English Eclair ACL 400' mag are standard metric or Imperial. Are some, or all of them, something else. Sort of a dumb question I know, but have to start somewhere. I took what looked like a 2mm screw securing the throat to an English magazine body and was hoping it was M2x0.4, but looks not. I don't actually have a thread gauge that goes fine enough, so improvised with fitting to a known M2. No tiny imperial gauge either.

Any help appreciated. Boris Belay will know.

Gregg.

[Aapo Lettinen]

I think Heikki stated sometime earlier that the Eclair screws are typically the Japanese thread. so different thread profile than regular screws.  I have just used the original screws for mounting motors because it is too hard to find compatible screws here.

One option is to just retap the threads to a common slightly larger metric thread. one size larger is almost always possible to do without compromising operation too much

Edited August 9, 2025 by Aapo Lettinen