Thank you. The term "First" or "Second" transitional variants came from Mr. F.A.Datig's book " Soviet Russian Tokarev TT pistols and cartridges 1929-1953". Here are some quotes from this excellent work:"...., all specimens of the Model TT30 Tokarev pistol noted have been relatively identical, this referring only to the true TT30 pistols of 1933 manufacture and not the"transitional" variants of 1934 and 1935..."
..."Specimens dated "1934" differ from the former only in that they incorporate the TT 33 type barrel whose locking lugs(grooves) encompass the entire circumference of the barrel. Hammer group assemblies are found to have only very minor differences, all other components being relatively identical. Pistols of 1934 manufacture are, for all practical purposes, merely TT 30 models but with TT 33 barrels. Because they are neither true TT30 types, nor are they ultimate TT 33, we prefer to designate them as TT 30, " First transitional Variation"...
..."Examples of the TT30 model dated 1935 employ not only the TT 33 type barrel but also a slightly variant hammer group assembly and may or may may display other minor technical variances. They do, however, still carry the insert unit in the blackstrap, easily visible outwardly, which may be said to be the only major holdover from the original TT 30 pistol of 1933 manufacture. Consequently, because of the feature remains in evidence, we have given this type the designation, "TT30, Second Transitional Variation."
..."From the foregoing it becomes clear that the first three years of series productions 1933' 1934 and 1935, included four variations,
1933 - Original TT30 pistols(the only year for this type)
1934 - - TT30, First transitional variation
1935 - TT30, Second Transitional Variation..."
All of the above from Mr. Datig's book.
I want to make a stand alone thread about these amazing pistols...There is an excellent work posted on Russian resource regarding history of these pistols, plus I have 1967 dated Dr. Bolotin's book(History and development of Soviet Firearms for past 50 years) from where I can produce some quotes...