.303 "K.37 .303 S.L." headstamp


There is an inert .303 round listed on ebay here
The seller says that the headstamp is: “K.37 .303 S.L.” What does the “S.L.” part mean? Self loading?? I have never seen a .303 with a headstamp like this before.


It means Stream Lined and was an early description of a boat tailed bullet. These rounds were used for Match shooting at Bisley and influenced the design of the Mark VIIIz bullet for Vickers guns.



This is a .303 Match Ball Mk 7z and will probably also be marked with the lower portion of the case being chemically blackened. It was produced by Kynoch in 1937 and the ‘SL’ indicates that it has a streamlined bullet.


I wouldn’t buy this anyway as the primer is struck, meaning that someone has made this up from a fired case, so the bullet is quite possibly the wrong one. The blackening has also by the looks of things been polished off. I just wanted to know what that headstamp meant.


I have recently purchased .303 rounds with struck primers from this Ebay seller. I do not believe that these were made up from fired cases and new projectiles. One round, a Mark 7, has a firing pin hit with no visible flattening of the primer, which leads me to believe that it was either a dud to start with or else it was struck after the primer was oiled. A Mark 6 round had a primer that may or may not be flattened, I just cant make up my mind, but it seems to me that a spare Mark 6 projectile is harder to come by than a spare Mark 6 case. This cartridge, I believe, was snapped after the projectile was pulled. Neither round appears to be expanded like they were fired in a notoriously oversized .303 chamber, but a determined cartridge builder could have resized them.

This seller is auctioning off an older collection that she inherited, and claims to know little about what she has, but so far all of the projectiles appear to match the case markings. The only real problem I see with this seller, from a Yank point of view, is that she is in Great Britain and many of the competing bidders are British and they are dealing in Pounds Sterling. Pounds in UK spend Just like Dollars in the US. For instance a Coke from a convenience store will set back the Yank about a buck and a Brit about a quid. The problem arises when you change dollars for pounds. Every pound costs almost two dollars. Cartridges from the UK probably appear to be moderately priced in the UK, but a little steep to this Yank.


You do have to be careful in the UK, there are an awful lot of fired cases with bullets re-seated around. These are pretty much worthless as collector ammo, as any old bullet can be used.