I’m such an idiot when it comes to trying to figure out what all these old shells from the 1926 Lake Denmark Naval Depot explosion are that I only recently discovered that the Navy at one time tried to make easier for people like me by stamping the caliber of the gun on the rotating bands of every shell. At least I thought they did until I took a look at an oddball 4" shell that someone picked up back in 1926. The ‘anchor’ is stamped ‘34’. That should correspond to the caliber of the gun just the same as the ‘50’ on the bands of the 3" shells corresponding to 3"/50cal guns. So was there a 4"/34cal gun? I can’t seem to find any mention of one. I do know that these 4" shells use a very coarse LH thread and a steel or iron housing for the base fuze.
4"/39 Cal. ???
The first one kind of looks like a 4"/50 Common (Figure 25 at top of 2nd attachment below):
This is from OP 1664 US Explosive Ordnance, 1947: http://bulletpicker.com/pdf/OP%201664,%20US%20Explosive%20Ordnance.pdf
Maybe your second projectile is a 4"/50 Special Common without the ballistic cap (Figure 24).
OP 4, Ammunition Instructions for the Naval Service, 1923 only mentions 4"/40 and 4"/50. I didn’t see anything about a 4"/34 in either document.
Below are scans of the 4"/40 and 4"/50 projectile dimensions from OP 4, Ammunition Instructions, 1923:
So it does. But that first figure (Figure 24)seems to identify this mystery shell with the large threaded plug which if I’m not mistaken was originally designed for bagged black powder filler. I saw something in the Bureau of Ordnance Reports that mention the bagged black powder bursting charges. And this 5" one seemed a bit different also.
Plus it lacks an annulus/crimping grove to hold the windshield + amour piercing cap in place.
Glad to see though that there are people interested in these old relics. I put most of them on e-bay for either the scrap value for the brass, or for as low as $4.50 for 3Pdr’s. I’m sure that my dad would’ve liked the idea that people in US and even in Canada are willing to pay shipping on pieces as heavy as 50lb 5-inchers. Found a fairly intact SEMPLE TRACER FUZE that I’m going to remove from a 3"/50 and keep with the ARMSTRONG fuzes. Think I’ll try sawing and splitting the steel shell base. Quality of the steel seems to compare to that of RR track.