Thanks for the clarification, - regarding rarity, I do not think many things regarding the Kar98k can be called rare, but speaking of barrel coding some makers are far less common than others. In this case 936-dfb (BSW-Gustloff Werke Suhl) barrels are rather uncommon on JP Sauer production but seen 1940-1942. So far 1941 is most common, 1942 next and 1940 the scarcest recorded, but I think this is more an issue with early rifles being less prone to have BC where you can see them (above the wood and owners are reluctant to disassemble) and partial "936" codes are hard to identify unless you can see "936" or the waffenamt e/4. I think 1940 S&S rifles are greatly under reported.
Certainly 1942 are the scarcest of all though, and this is clearly a product of rationalization, - the period when firms were focused on a narrower range of products based upon that firms ability-capacity and the needs of the Army. Gustloff Werke Suhl was re-focused primarily on the MG42, dropping the 98k barrels to focus on MG 42 barrels. (They had moved their 98k production to their Weimar facility in early 1939, only continuing with barrels)
In reality I doubt S&S (Sauer) needed much help with barrels, that was their main part they made, and they had CGH to help (they were no slouch on barrel finishing), and you do not see a great deal of barrel sub-contractor use on S&S assembly.
Certainly 1942 are the scarcest of all though, and this is clearly a product of rationalization, - the period when firms were focused on a narrower range of products based upon that firms ability-capacity and the needs of the Army. Gustloff Werke Suhl was re-focused primarily on the MG42, dropping the 98k barrels to focus on MG 42 barrels. (They had moved their 98k production to their Weimar facility in early 1939, only continuing with barrels)
In reality I doubt S&S (Sauer) needed much help with barrels, that was their main part they made, and they had CGH to help (they were no slouch on barrel finishing), and you do not see a great deal of barrel sub-contractor use on S&S assembly.
Posted up the extra/corrected info and picture in my original post. My apologies for the delay. You were right about the questionable e/37 proofs, they were in fact WaA4. Would you say that the ce42 with the dfb barrel is rare or uncommon? If so, it's such a shame that the bore is garbage.