Ambivalent
Junior Member
At the time a smooth bore gun like an over sized tank gun might have been considered giving a much higher muzzle velocity and range.
I remember a project to develop a round for the 155mm army gun with four fins on the tip on a surely extremely expensive bearing to guide the shell to its target. A guided smooth bore projectile must be much cheaper and can have a longer range.
Eh, any time you talk moving parts cheap ceases to be a part of the discussion. The advantage of a smoothbore gun is that it withstands erosion from high powered charges better than a rifled barrel will so their performance doesn't degrade as quickly. That is why they prevail in tank main gun designs. The energy necessary to penetrate modern composite armors dictates really hot rounds that are hard on barrels. The Brits hung on to their rifled barrels so they could stick with their HESH round, and changed barrels often, but when the great majority of potential enemy tanks no longer presented a target HESH could defeat, they too adopted smooth bore barrels.
You will notice those tank rounds use a sabot and have fixed fins. The environment in a big gun like that isn't really conducive to keeping things like folding fins in place. It can be done, and is done, but not inexpensively.