11mm M 1873 Revolver (and ammunition) from 2011 UK Riots

Here are some photos of an 11mm MAS 1873 Revolver (and ammunition) that was confiscated by police during the 2011 London riots. A gang in the West Midlands city of Birmingham were filmed trying to shoot down a police helicopter with this, a FEG PA63 and two other pistols.

I can’t see the calibre marking in the headstamp, but can make out that it is Starline Brass. Starline doesn’t list this calibre in its range, so the brass must have been modified from another calibre. The reloads look too well made to have been made by the gang members. What case is commonly used to convert to 11mm French? They do look to be possibly rimless cartridges in the photo. Would a .45 ACP chamber in a MAS 1873? I understand that even if it would chamber, no one with any common sense would try firing it (higher pressures and larger bullet diameter). The chambers could also have been poorly drilled or filed out of course.

It is odd that they would use this gun when our cities are awash with illegal semi-auto pistols in the usual calibres. The only explanation that I can think is that the revolver and cartridges were stolen from a legitimate shooter before the 1997 handgun ban.

44 Colt is very close at 11.15 and the 11mm MAS being 11.16. An image of the Starline 44 Colt is here:

Although in the blurry image it looks like the caliber lettering is much closer to the stars, something closer to what the 44 s&w special headstamp looks like from them, but that bullet diameter is closer to 11.0:

Good evening
44-40 and most usually used to reload 11/73.

Is the 11mm MAS a section 58? meaning anyone can own one without a licence. .44 Russian is.


The only thing would be the price which would (as a sec58) be sky high. It does tie in with the strange story of Mick Shepherd who was accused of supplying sec 58 to gang members. Don’t bother reading it all it goes on and on but you might like to browse his prices.


Yes the 11mm MAS is Section 58 (For non-UK forum members: in the UK there is a list of mostly 19th century era calibres where the guns can be owned without license. However, you can’t shoot them or own any ammunition for them).

I thought that the chances of them fiding newly made ammunition in an unusual calibre were very slim, which is where my stolen gun and ammunition theory came from.

There are several books on cartridge conversions and making ammo for firearms for which ammo is no longer available. I would imagine somebody has a copy or two.
COTW often has suggestions although the references appear to have been progressively removed from recent editions. Possibly for fear of litigation.

Donnelly suggests the 44 magnum or special cases. Reported bullet diam is .425". He suggests to trim cut down the 44 cases, reduce the rim diam and then reload the modified brass with 44 special dies.

This thread could come close to discussing reloading, which is against the rules.

I agree with Falcon that the seized ammunition looks to be rimless.
The headstamp is too blurred to distinguish, but the cases might have started life as 44 Auto Mag.
Police foresics will no doubt have determined the powder type to attempt to locate the source. They will also have attempted to locate the source of the primers (now subject to purchase controls in UK) and the cases. Unless that is that they already have identified the source/assembler of the ammunition.
Whoever assembled the ammunition has ‘some’ knowledge. Safe or dangerous could only be determined in a lab or proof house.
Legally speaking the revolver shown is not Sec.58(2) It ceased to have the exemption from licensing afforded to antiques of obsolete calibre by Sec.58(2) the moment that someone decided to use it.