303 Auxiliary devices

These are examples of 303 Auxiliary devices. The first one is the 303 cum .22 Parker-Hale as described on p.143 of Hoyem Vol.3 with the removable breech plug. The .22LR is interesting with the 2 small point crimps on the case. The second one is the 303 cum .22 Vickers with the off-centre chamber for rimfire so that the center fire pin of the Vickers will strike the rimfire of the 22 LR short. There is a logo on the base, but it is too faint to make out exactly what it is, but in all probability BSA, as well a patent number on the case, but again very faint.

The question is regarding the third one. It is too small for the 297/230 Morris and takes a 22LR Short, but only just. That would present a problem as the rimfire would not be struck by a centre-fire firing pin. There is an “EFD” on the shoulder of the adapter, but apart from that there are no other markings.


Hello Dan - Nice photographs!

Could this link be of any use? https://forum.cartridgecollectors.org/t/30-40-krag-auxiliary-chamber/2689/1


The description on the thread matches the Parker-Hale device.

Above is an example of the Mullineux adapter. Looking at IAA #443, this 3rd example is not there either. It was made by Enfield as noted by the EFD stamped on the shoulder, but apart from that I don’t have any further info.


I presume this is too short for the 297/230 Long, but have you tried the 297/230 Short.


your third one is certainly made at Enfield and is for the Brit .303. you say it would not be struck by a central fire firing pin, these were not made for rimfire 22.
these used a .22 CENTRAL FIRE cartridge. I have some here and some boxes. sorry not able to post pics on this site! but could send a jpg to your email if you wish. Jim