Seeking driving band identity

[GeoffR]

Can anyone identify the type or size of shell these two fragments of driving band came from please? They are representative of many other similar fragments found on a beach in SE England in the 60s but no longer. 3.7" and 4.5" AA guns were in the vicinity in WW2, but the band width looks like a larger calibre shall: width 1.4" (35mm), high flats 0.2" (5mm) wide and grooves 0.3" (7.5mm) wide. All dimensions are approximate as the items have been distorted by explosion. Interestingly, although 'exploded', one piece has no rifling marks so has not been fired.

 

[2pounder]

3.7in AA bands are 35mm apx and 4.5in AA bands are 53mm apx. so that would appear to indentify your fragments.

 

[GeoffR]

Thanks 2pounder, looks like a fit. With 28 rifling grooves in the 3.7 barrel each pair of adjacent grooves and ridges = 0.415", which is not too far from the 0.5" I measured on the fragments, especially as they are likely to have been distorted when exploded.

In case other shell bands have a similar width I did a search for a photo of a (WW2) 3.7 shell to see if they showed the same two distinctive grooves around the band. To my surprise I couldn't find any with the sites search facility, or even googling it. I will try again later.

 

[2pounder]

suprised no 3.7 in AA pictures, they are not that common so heres a snap I took earlier. the band should show the grooves you have assuming it does not go too fuzzy when magnified.

 

[GeoffR]

Thanks 2pounder, that just about clinches it. I couldn't get it very large but large enough to see that familiar ring groove pattern. I hope it is unique to the 3.7 inch.
My search still didn't find any other shots of the shell. The gun, yes, lots of the gun, some of the cartridge case, but none of the shell itself, which surprised me.
Thanks again.