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I have what I believe may be a P.m.K Tropical loading.
The photos will explain more than I can hopefully.
I pulled the projectile because there was what appeared to be verdigris just above the case mouth making it almost impossible to witness any case mouth sealant or colour.
It was a little surprising however to see black paint or ink on the projectile below the crimp mark.
One photograph shows what I believe to be the small hole consistent with P.m.K projectiles.
Cleaning as carefully as I can with a brass brush it seems the primer anulus is black.
Projectile weight is 146.6 grains.

I’d like some fellow opinions to see if I’m on the right track or am I mistaken

Regards Peter


A cartridge with this case lot number from Polte is known as a Spr. round.
The weight of the cartridge is about 350 grains and the annulus colour must be black.
This is a very scare round. Unfortunately I cannot show your lot number but some other.



Thanks Dutch, Unfortunately I have dumped the powder as it was moist and beginning to corrode the case internally.
Can you shed any light on the Spr. round, what it was used for and years of manufacture ?

Thanks Peter

The SPr. (Pr for its white phosphorous filling) originated in WW1 for use against balloons. It had no steel core, because incendiary effect was the goal. It had a soldered hole like the later PmK to start ignition and create a smoke trace. Otto Morawietz wrote that at the end of WW1 stocks had to be destroyed because bullets became leaky. I do not know to which extent this was eventually done.

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Yes, that’s my problem.
The SPr bullet should be absolute after WW1, replaced later by the PmK. They were still loaded until 1940.
Because I never seen a box label I cannot tell you if the bullet was made during WW1 or later.
It could be they were made for export like the coded one for Spain.
The cartridges found so far have all a head stamps witch factories were all a member of the Polte family.



Hi friends,
sending photo S.Pr. and P.m.K for better orientation.
Weights and measures are given in grams and millimeters.


please inform is that the same round that was also issued in the late 1930 with the RED STRIPE
across the the bottom and later the stripe was replaced with the black bullet???

Sherryl, the red stripe on the head was the early marking of the “PmK” API (WP based), later replaced by a black PA and black CM (latter only on tropical loads).
The “all black” projectile here was the “SPr” which was a WW1 development and was a WP “incendiary only”.

Thanks EOD
Thanks for the info there is so much to remember at my age that brain is just about fried

The original S.Pr rounds of WW1 could be identified on the 120° head stamp like the one on @franta his board. These cases were specially made by Spandau for this round.
The change, identifying the cartridge was done in April 1918. The bullet became a black coating and instead the 120° head stamp, a normal case was used.
At the end of 1918 the “F” cartridge was introduced. It had also a black bulled but a red annulus. This cartridge had a steel core.

Just as the S.Pr, the PmK changed there identification over the years.
It firs started with a red stripe over the base. The second model had a red annulus. They found out soon that that it looked the same as a SmK. Most of them were reworked with a black annulus (mod.3) and than it became a black annulus. The PmK made at the end of 1943/44 were also made with a primer 43. Without the box label, this primer looks like a 30/40. It is hard to identify but the air force did not except this kind of primers only the 88 and 43.


here a nice cut of PMK SMK SMKH

I have one with a stamp S67 P 18 3 however the annulus is black but the bullet is not???
Advise Sherryl

in first WW the annulus for BALL was black…so you have an ordinary S Ball-Cartridge. The heavy Ball (SS) got in 1918 a green annulus. The SMK got a red annulus. For Secret reasons the first SPr got a 3 digit hs as shown here before…the changes to the black bullet, and the red p.a. where already fescribed by dutch…