On 8 February 2016 at 16:12, Gene Heskett <ghesk...@wdtv.com> wrote: > > One question remains: Does the thread even have to have a spiral > component, eg does it need to actually advance into the hole as it > turns? Common sense says it should, in order to achieve a gas tight > seal against a shoulder at the bottom of the bore. OTOH, with a shell > casing supplying the breach seal as modern bolt rifles do, if the > headspace when closed is tight enough to prevent a casing head > separation, the need for the spiraling thread is removed.
Screwed breeches of the Welin or de Bange type are only used with bagged charge guns. They both use a de Bange obturator for sealing whereas a brass-case gun used the case for obturation. This might mean they need no lead, but the pictures seem to indicate one. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
