USN 1 Pdr and 1 Pdr Heavy question

[raymeketa]

I'm not sure where to post this, but it looks like as good a place as any.

I have two USN cartridges, circa 1915. One headstamped 1 Pdr and the other stamped 1 Pdr.H. I have always assumed that these are a 1 Pdr and a 1 Pdr Heavy. Same case but the 1 Pdr.H is loaded with a longer and heavier projectile than the other.

Are those designations correct? I've read some bits and pieces of information that infers that the "heavy" designation refers to the gun rather the cartridge.

Anyone shed any light on this?

TIA

Ray

 

[Gspragge]

All of the 37x136r case loadings (USN) are 1 Pr Heavy regardless of the projectile used. The 37x95 U.S. cases would be considered to be the "Light" loading or round, though the term doesn't seem to be used as such for these. Other export versions and so on are marked 1 Pr, but would still be a Heavy in USN parlance.

However the Hotchkiss 37x95 loadings are called 1 Pr Light and the 37x120 loadings are called 1 Pr Heavy to differentiate between them. Since the U.S. 37x136 a longer narrower case is an equivalent to the 37x120 more or less the terms seem to have carried along with them. At some point the Heavy term became Official with the USN and the cases were marked as such. I think around 1900.

There are a number of guns that used these including the "Heavy" 1Pr Maxim.

What exactly is the headstamp on the 1915 case.

 

[raymeketa]

Thanks Gspragge. Still sounds a bit confusing to me, but thanks. Some of the conflicting info that I read came from the Naval Weapons site where there is no mention whatever of a heavy cartridge, only light and heavy guns. And the fact that the two cartridges I have are headstamped differently.

Neither cartridge is headstamped 1915. I said "circa 1915" because there are dates on both the cases and the projectiles. The 1 Pdr case is dated 1918 while it's projectile is 1917. The 1 Pdr.H case is dated 1906 and the projectile is 1914.

Ray

 

[Gspragge]

Well the light guns are 37x95 and the heavy ones are 37x136. Some 37x136 cases are marked 1Pr - H for heavy but some not. But you could not load a 37x136 into a light gun , I guess you could put a 37x95 into a heavy gun with perhaps exciting results. This is pretty much a U.S.N. designation as other wise they are just called 1 Pr. regardless of case length every where else. There are quite a number of marks of 37mm guns and that alone is confusing.
The Navy reloaded the cases also so they lasted a while. Starting in 1900 the cases appear with a circular crimp, I think this is on account the belt fed Heavy Maxim so that the projectile didn't get stuck in the belt.