[meatloaf]

Naval guns are not hand loaded. Since 155 mm is about 6 in and naval guns are 5” do you envision an issue adapting for naval use?

[Chainmail]

It's possible - but some ferocious miniaturization is called for: 127mm is significantly less volume when compared to the 155mm - about half.

If you are conversant, then you remember the Extended Range Guided Munition (DRGM) that was supposed to extend range to 150NM - but when it got there, there was insufficient room in the projectile for effects to cause harm to the enemy and it took several minutes in its travels - which eliminated moving targets from your list.

As with many expensive and insufficiently thought out projects, it died a natural death.