3inch 20cwt Practice or AP shot

[BMG50]

I have two un banded 3 inch 20cwt projectiles practice shot, similar metal stamping but different lot number to a previous thread and marked QF after I/N. I could see an original red ring on the nose of each projectile faintly one higher than the other and a trace of white.
I was quite interested they are Naval practice shot as mentioned in anther thread. I have a Naval 2 pounder practice shot but the painted band is yellow and the stencilled N is white, I thought the 3 inch would be marked in yellow as well but the noses have red bands. These are not practice AP rounds for the Churchill. How would this 3inch 20cwt be marked up, black body red painted ring or white, would it have a large N stencilled on the side?

 

[2pounder]

think there is a P in the markings and CI which mean practice and cast iron so could the red band be for a tracer cavity in the base? the 2pr did not have a tracer. there should be a yellow band around the mid of the 3ins.

 

[BMG50]

The mystery is that there is no tracer on the base but red ring painted on the nose.It has a P stamped on the side. If it was a Naval used projectile the i assume the nose band would be painted yellow and marked with a large white N just like the 2 pounder practice. Just wondering if other calibre's in practice solid shot are differently large or small.

 

[BMG50]

After closer examination i thought i would check the remaining red colour paint just to see if it is not discoloured by rust. Upon scraping lightly i found that the original colour is in fact yellow. So i assume Naval solid shot painted up like the 2pounder Navel practice, i assume with a large stencilled N, not sure if the N was a similar size to the 2pounder.