Helped Needed To Identify Unknown Projectile

[AirMechanic]

Hello, I am new to the forum and was hoping that someone on here would be able to help me identify a projectile that I recently found at a flea market in the United States. After attempting to do some internet research of my own on this item, I suspect that this shell may be a British 3 inch naval shell, but I may be altogether wrong. The projectile is about 9 1/4" high (234.95 mm) and about 3 3/8" (85.725 mm) in diameter. It weights about 20 lbs (9.07 kg). There are markings on it that say "103" and a date that I can't quite read, "5/?3", followed by "DKRF5484" and "BM145". Hopefully these markings will aid in the identification of this piece. Also, I believe that since the shell has a threaded hole in the bottom and it does not have a copper driving band, that these features will also help narrow down an ID as well. If anyone can identify this shell for me, I'd really appreciate it!

 

[Slick]

I don't know the answer, but the lack of a driving band leads me to believe it's a rocket warhead.

Similar to this: http://uxoinfo.com/blogcfc/client/includes/uxopages/Mulvaney_Details.cfm?Ord_Id=FB161

 

[kahu1]

I think Slick has got the ID.
A lot of the British 3" 25lb AP rocket projectiles were made from altered(driving band turned down,spigot screwed into tracer cavity) 25lb Artillery projectiles, but i believe the earlier ones were produced specifically as rocket proj.,and like this one would have an adaptor spigot screwed into the base.

 

[spotter]

with driving band
http://www.bocn.co.uk/vbforum/threads/4162-3-inch-AP-25-Lb?highlight=rocket

 

[AirMechanic]

Thanks for the info!