with provision for additional propulsive charges, or for varying the length

Full Title

Projectiles or missiles, not otherwise provided for, characterised by the ammunition class or type, e.g. by the launching apparatus or weapon used (F42B10/00, F42B12/00, F42B14/00 take precedence) > Ordnance projectiles or missiles, e.g. shells > Mortar projectiles > with provision for additional propulsive charges, or for varying the length