Fede iam inclined to aggree.the two examples you show are similar and the name is the same . the second photo shows a rifle descibed elswere as the kretz rifle useing a coil spring in the but hooked to a chain that operates the bolt.
I should have said in my previous post that the calibre was not .276 inch Pederson as mentioned by Fede but .276 inch Enfield, a much larger and more powerful round intended for the Pattern ’13 rifle. The Pederson had not been developed at the time this rifle was made.
Device for Transforming a Repeating Gun into an Automatic Gun. United Kingdom Patent 191305866-A
[en] 5866. Tatarek, E., Blum, F., Kretz, F., Szapary, G. L., and Dory, B. von. March 10. Breech actions, sliding breech-block. – Consists in special mechanism for converting a hand-operated repeating rifle into an automatic rifle operated by the powder gases. On the muzzle of the barrel is arranged a sliding sleeve 4, Figs.
1 and 8, adapted to be driven forwards by the rush of gases from the muzzle. This forward movement tensions a spring 13, Fig. 1, which afterwards actuates the
breech-opening mechanism. The sleeve is held in its forward position by a pivoted catch 16 acted on by the spring 13 and by a smaller spring 15, Fig. 8. The invention is shown applied to a Mannlicher rifle in which the breech-bolt cannot be opened until the trigger is released. When the trigger is released, the spring 13 pulls a rack 11, Figs. 1 and 3, forwards, thereby rotating a pinion 9 and driving rearwards a second rack 12, which is connected by a rod 19 to the bolt operating slide. When the tension of the spring 13 is lowered, the catch 16 is released by the smaller spring 15, Fig. 8, and the sleeve 4 is returned to its normal position by a spring 6.