The 7.62mm CONV rifles were nothig to do with the Army. Maybe they were made for sale via the usual firarms dealers. Interesting picture of the 00 bolthead Any idea of the measurement against the others Thunderbox? Of course it's easy to get a 00 bolthead by grinding it down a gnats knacker on the surface grinder.

We've seen an L39 (above) with a 00 bolthead and also above, an L39 built using an used Mk2 body (also above - note the cut-off block). But does anyone have an L39 based on a Mk1/2 body?