Jamming issue is a subject in itself; no space for that here except to say the design like all straight pulls lacks the leverage advantage of a turn-bolt, but as long as dimensions and case quality are maintained it's not a problem. The Soviets would have had no trouble figuring all that out; they were already well familiar with captured Steyr-Mannlichers. The rifles were retained for sniping in the CEF right to the end of the war, and according to Frank Iriam whose book you would probably find interesting, Ross Mk.IIIs were supplied new from the factory into 1918. We know from photos they were used with and without scopes as the factory iron sights were considered good enough by some.
The Lee Enfield is even simpler than the Mauser actions such as the Springfield. Ross Mk.III is pretty simple too, though machining is somewhat complex. Not that it matters much as soldiers were not supposed to take them apart in any case.
No, am not aware of any movies or docs dealing with the subject in the interwar period.
Does Whacker make a definite statement to that effect based on records he cites?
When you say "were not available" you mean they were not on issue to the Red Army? Probably not beyond experimental purposes, as the OGPU/NKVD would get priority if they wanted it. Probably there was a certain amount of overlap between the Red Army and "the Organs [of state security]" as they were called. What the Red Army may have begun, may have been adopted by the Organs or vice-versa. That all remains to be determined.
Yes, I was suggesting the PEM scopes would not appear in film being new and secret and therefore the experimental stuff could be used as it was now effectively obsolete.
Whacker may be right, but of course, but even if there is some documentary evidence that such schools were not operated, one has to remember that until the repudiation of Versailles, a degree of duality or pretense was maintained internally as well as externally that Germanywas conforming to the Treaty requirements, when in fact of course she was not; the bases in Russia
being the most glaring example. What happened in Russia (probably) stayed in Russia"
That would be no more than obvious and customary military secrecy. Those who need to know do, and the rest don't, at least not officially.
Just something to bear in mind.
Who was removing and selling scopes in the 1930s? The British Empire and Commonwealth was fielding the P14 with Patt.18 scope in limited numbers, and the selling off of the UK's WWI scopes was long over by then. You'll see that Skennertion refers to the proposal that the better WWI Aldis scopes be kept in store for possible future reuse, but we can see from the miscellaneous scopes fitted to the 421 Alex Martin P14 conversions done in 1940-41 that they almost certainly were not. And if further evidence was needed, many of those better Aldis No.3 and 4 scopes showed up in the 1920s and 30s being fitted to sporting rifles by leading gunmakers.
I believe the USAdumped the Warner & Swasey scopes in the 1920s judging by the advertising of them for sale, though they probably were available from dealers into the 1930s as even at $7.50 a piece they apparently didn't sell very well!
I haven't read Whacker, but if he documents that then that is an interesting angle, perhaps suggesting that by the early 30s sniping was indeed being forgotten and considered passé in the Reichswehr. Is there any evidence that the scope and mount combination fielded by the Reichswehr after WWI was being disposed of at that time? If not, that might suggest merely that WWI rifles, or just scopes, that had been kept hidden from Versailles-mandated destruction through the 1920s, were by the early 30s considered to be no longer needed and could therefore be sold off? Sometimes such decisions are made by "one hand" while "the other hand" doesn't know what is going on, and depression-era economy or fund-raising may have been a part of that as the Depression hit Germany very hard in the early 1930s. Could be that some were sold from some military districts/departments and not from others. One would have to know exactly how such things were organized and controlled in Germany at that time. We do know that at least some Gew98 SSG's were still in store well into WWII because Waffen SS formations were equipped with them at that time..
I was referring to those Russians who actually served in the Russian force sent to fight in France- it's not a well known episode of the war in the Anglosphere. Russian Expeditionary Force in France - Wikipedia