A military firing range on the Severn Estuary shown on the 1921 edition OS 25? plan, though absent on both the first and second editions (surveyed 1882 & 1901), was probably established during the First World War.
The map shows the position of the targets, at the south-east estuary end of the range (NPRN 419581), with glacis ditch and storage area and with control or storage building nearby, and also the location of shooting positions spaced at 100 yard intervals as far as 600 yards extending to the north-west.
The range remained in use until it was bissected by the M4 motorway in the 1990s as the Second Severn Crossing was built. Subsequently, the Ministry of Defence range was relocated a short distance along the estuary to the south-west. The south end of the old firing range is still used as such though it is now privately owned (NPRN 419581). Air photos show the 100 yard and 200 yard positions still extant along with the target area, though all features are considerably developed since their first map portrayal. The 300 yard positions now lies beneath the motorway. North of the motorway, where the former range has reverted to farmland, field investigation showed the 400 yard and 500 yard shooting positions to be ploughed out with only faint banks now appearing on air photos. However, the 600 yard position survives as a grassy bank in pasture. The bank measures 25m long (NE-SW) by 5.5m wide and 0.5m high on the north, 0.75m high on the south, and with no obvious ditch. According to early map depictions this may have been, initially at least, the only firing position so constructed, the others being portrayed only as points. The 1921 map also shows a rectangular building on the edge of the Summerway Reen, at the east edge of the range between the 500 yard and 600 yard mounds; only surface irregularites in the field hinted at its former presence. A modern brick-built structure lies to the west alongside the access track to the range.

David Leighton, RCAHMW, 4 November 2013