QF 3.7-inch AA gun: Difference between revisions - Wikipedia

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===Mk VI===

Like the Mk IV this was based on the 4.5 inch barrel design lined down to 3.7 inches, and using the 4.5 inch size cartridge. However, Colonel Probert changed the barrel to have gradual rifling: the rifling groove depth decreased to zero over the last five calibres of the barrel before the muzzle. This smoothed the two [[driving band]]s of a new design shell giving reduced air resistance and hence better ballistic performance, and causing far less barrel wear. The maximum ceiling for the gun was about {{convert|15240|m|ft|abbr=on}}. It was mounted on the Mounting Mk IIA and therefore deployed in static emplacements only. In service from 1944 to 1959.

As of 1949, erosive cordite propellant was not used with Mk 6 guns, but instead 17 lb and 2-6 oz of different single-base nitrocellulose propellant (as opposed to slightly over 7 lb 1 oz of cordite or around 8.5-9 lbs of single-base for Marks 1-3 guns)<ref>https://stephentaylorhistorian.files.wordpress.com/2020/09/26-manuals-3338-anti-aircraft-ammunition.pdf</ref>

==Performance==