<p>Diagram of British Capped AP (Armour-Piercing) Shell with Ballistic Cap, Mk XXII BNT, 1943, for <a href="https://en.wikipedia.org/wiki/BL_15_inch_Mk_I_naval_gun" class="extiw" title="en:BL 15 inch Mk I naval gun">BL 15 inch Mk I naval gun</a>.
<br>Explanation of markings on shell, top to bottom ,left to right :-
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<ul><li>15" XXII : 15 inch Mark XXII shell.</li>
<li>B denotes 6 <a href="https://en.wikipedia.org/wiki/List_of_British_ordnance_terms#C.R.H." class="extiw" title="en:List of British ordnance terms">c.r.</a> head (the dimensions of the ballistic cap)</li>
<li>NT denotes the shell has a night tracer in the base. Hence the base fuze is not flush with the shell base, but is recessed into the shell.</li>
<li>GNB denotes the filling contractor's initial. 8/43 denotes date shell filled.</li>
<li>EXPL PEL 3 1/4 oz PA : denotes the exploder is Picric Acid, 3 1/4 oz.</li>
<li>T inside the semi-circle segment indicates type of tracer shell has fitted.</li>
<li>FZD159 denotes serial number of fuze is 159. 4 above 7/43 applies to the fuze : denotes lot number 4, filled July 1943. BL/I denotes the fuze maker's initial and mark of fuze.</li>
<li>Red band denotes shell is filled.</li>
<li>70/30 denotes Shellite filling makeup : 70% Lyddite, 30% dinitrophenol.</li>
<li>The circle on the band around the middle of the shell indicates centre of gravity.</li>
<li>N denotes intended for Naval use.</li></ul>
War Office, UK
circa. 1943 - 1944
<p>Text Book of Ammunition, 1944.
<br>Downloaded from Steve Johnson's Cyberheritage website at <a rel="nofollow" class="external free" href="http://web.ukonline.co.uk/stephen.johnson/arms/shel15.jpg">http://web.ukonline.co.uk/stephen.johnson/arms/shel15.jpg</a>
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<br> Other sourse B.R. 932, Handbook on Ammunition, 1945. British Navy ammunition from WW II, Plate 8 in APPENDIX at <a rel="nofollow" class="external free" href="http://www.hnsa.org/wp-content/uploads/2014/08/br932.pdf">http://www.hnsa.org/wp-content/uploads/2014/08/br932.pdf</a>