A single Broad Arrow was the early code for Royal Ordnance Factory Radway Green, Cheshire, UK. Later in 1941 they switched to the familiar “RG” headstamp.
Two Broad Arrows is ROF Spennymoor and three is ROF Steeton.
These codes were used early in the war to disguise the fact that these new ammunition factories were on line.
Tony did ROF Steeton ever make .303, I have never found any evidence of them making .303 but I am a novice at this evidence hunting :-)
I only live 5 min’s away from the site where it was.
No, Steeton made 20mm Hispano for the Air Force. The three arrow headstamp appears on these.
The sister factory at Thorpe Arch made 9mm Mark 2z in the mid 1950s.
Radway Green, from its beginning, also made pre-Belted .303 for Aircraft Browning ANM2 Guns…whilst cleaning out part of my Ammo Room, I found several Part Belts, all ^ 1941 VII, still in their BMG Links ( for .303). A large Quantity of this ammo was surplussed in Australia in the period 1967-75, both Belted BMG, and Packed (loose) in 48 rnd Cartons, from a wide variety of British and Canadian Factories ( R^L, K, ^ and ^^, K2, K5, CP & C-P, GB & GBF, and DAC^ & DAQ^ & DI Z.)
Source of this ammo was unknown, but a Lot of the Canadian ammo came out of Aust. and NZ Airforce stocks (From the crate Labels).