On 16/01/15 15:59, F. George McDuffee wrote:
On Fri, 16 Jan 2015 09:02:02 -0600, "Paul K. Dickman"
wrote:

snip
Llama used an oddball proprietary thread on those screws. You will not find
a box at the ace hdw.

http://www.gunpartscorp.com/Search.h...rew+&man=LLAMA
/snip

Any one know their rationale for doing so?


It might be they had the tooling to make them and so used it. IIRC it
was MG with the XPAG engine that had French metric threaded bolts but
with Whitworth head sizes as a result of using machine tools moved from
the French Hotchkiss machine gun factory to England due to the war.