Re: Bullpups advance (slowly)

From: sddso (jspragg_at_iw.net)
Date: 02/06/05 

Date: Sat, 05 Feb 2005 19:07:22 -0700
To: sci-military-moderated@moderators.isc.org

damian wrote:

> Once Par Leijonhufvud <usenet@hunter-gatherer.org> inscribed in stone:
>
>
>>Paul J. Adam <news@jrwlynch.demon.co.uk>:
>>
>>> (Blanks jammed a _lot_ with the L1A1. I came to the conclusion that this
>>> was deliberate, to give us much practice in clearing stoppages in a
>>> hurry. Where a particular rifle - *** number 72, for the record - would
>>> struggle to fire twenty blanks without a stoppage, it would happily fire
>>> 1,200 rounds of live ammunition in two days without a single failure)
>>
>>I'm not familliar with the weapon in question, but in that case I would
>>suspect that the gas pressure or recoil force was different between the
>>blanks and the live rounds.
>
>
> In the brief experience I had with the SLR (L1A1) the primary mode of
> failure when firing was actually the extraction of the blank round
> base only, leaving the rest in the chamber. Easy enough to clear, but
> a fault in the construction of the blank round rather than anything
> else. From memory the base was aluminium with wall about 1cm high
> into which fitted a plastic top which had the shape of shell and
> bullet with a rough crimp at the top. Turning the gas setting down
> might have helped, but it was otherwise reliable (more so than the old
> M60 GPMG's) so I preferred to accept that at the price of things.
>
> Damian.
>---------------------------------------------------

Self-loading military rifles and machine guns typically exhibit poorer
feed reliability with blanks than with live rounds -- even when brass
cases are used.

Gas-operated guns require a certain amount of pressure over a certain
duration to work right. They need a plug or constriction at the muzzle
to develop enough pressure to function the action.

Blanks are loaded with much faster powder, and the pressure-vs-time
curve is very different. A charge of blank powder fired in a live
cartridge behind a solid bullet is very likely to cause a case rupture
and severe damage to the firearm (and injure the shooter).