Here be the Gospel truth, chapter & verse, from Bert, Chief Sachem of the Winchester Collector's forum:


Bert H. said 
The 25-20 WCF (repeater) cartridge was first offered in the August 1895 catalog No. 55. It was available in both black powder and smokeless when it was introduced. The 25-20 W.H.V. load was first listed in the 1905 catalog.
In the August 1895 catalog No. 55, the 25-20 WCF ammo was listed as follows;
Black powder cartridges were $16.00 per thousand
Smokeless powder cartridges were $25.00 per thousand
In the April 1900 catalog No. 65 the 25-20 WCF ammo was listed as follows;
Black powder cartridges were $16.00 per thousand
Smokeless powder cartridges were $19.00 per thousand
In the 1905 catalog No. 72 the 25-20 WCF ammo was listed as follows;
Black powder cartridges were $16.00 per thousand
Smokeless powder cartridges were $19.00 per thousand
W.H.V. cartridges were $21.00 per thousand

Redsetter wrote on Sep 3^rd, 2018 at 2:14pm:


I had the opposite thought. Remarkable that Winchester picked it up so quickly! I'm not sure it can be proven who did it first, but Marlin came out with it in their Model 1889 before Winchester came out with it in the 1892.
Marlin made 34 of the Model 1889's before switching to the Model 1894. The first 1894 in .25-20 M was in 11-8-1894, which would also be previous to the time frame Bert H puts for Win. bringing out the .25-20 WCF. (copy of Marlin's .25-20M)
So it seems if Bert H.'s info is correct, and we know Marlin factory records are correct, then Marlin did indeed beat Winchester to the .25-20 cartridge development. Even without considering the earlier 1889's in this caliber.

Bill Brophy covered it in his book on the history of Marlin, Frank. He lists the 34 1889's made, which is such a small number most Marlin collectors will never see one. I sure haven't.
But I've spoken with Rick Regnier who is the secretary for the MFA Collectors Assn., and he confirms Bill's number of 1889's in .25-20. Both he and Bill Brophy gave me the date of the first known 1894 Marlin in .25-20, which was gleaned from the factory record books.

Yes Frank, Win. did offer the 1873 in .32-20, and a fair number made. Not sure of the introduction date, but COTW states 1882 date for the caliber in the 1873.

Redsetter wrote on Sep 3^rd, 2018 at 9:56pm:


I don't have that info, and Bill's book doesn't list the first 1889. But he does list the first 1894 in .25-20, which is the date I posted previously. I'd only be guessing that the 1889's were earlier as 1889 production overlapped after the 1894 model was introduced. So it could be earlier, the same, or later.

Winchester did the same thing.
I have a non-takedown Model 1897 receiver marked shotgun with an 1893 marked barrel.

Aaron

marlinguy wrote on Sep 3^rd, 2018 at 8:01pm:


Yes!, by about six months, as Bert has confirmed, based on his exhaustive knowledge of Winchester records, but with this difference between the two cartridges: the .25WCF could be fired in a .25-20 Marlin, but not contrariwise according to Bert, because the original Marlin case had a sharp shoulder that wouldn't chamber in a Winchester.  So the interchangeability of the two cartridges went only one way, leading eventually to the obsolescence of Marlin's .25-20.

It's interesting to note that, in the Center Fire Cartridges section of WRA catalog No. 55, WRA shows the 25-20 Winchester Model 1892 cartridge (Adapted to Winchester Repeating Rifles, Model 1892), and also shows the 25-20 Marlin cartridge (Adapted to Marlin Repeating Rifles).
Both cartridges were available loaded with Black or with smokeless powder, with the smokeless powder loading being an equivalent in velocity of the Black powder loading.
The 25-20 (Adapted to Winchester, Maynard, and Stevens Single Shot Rifles) is also shown, though it is spec'd as being loaded with 2 more grains of Black powder than the amount used in either of the Black powder WRA 1892 or Marlin Repeater cartridge loadings.
The 25-20 Hi-Vel cartridge (Adapted to Winchester Repeating Rifles, Model 1892) appears in 1903 starting with WRA catalog No. 70, while the 25-20 Marlin High Velocity cartridge (Adapted to Marlin Repeating Rifles) appears a bit later in 1905 starting with WRA catalog No. 72.
In 1918, in WRA catalog No. 81, the Center Fire Cartridges section still shows both the 25-20 Winchester Model 1892 cartridge (Adapted to Winchester Repeating Rifles, Model 1892), as well as the 25-20 Marlin cartridge, but... the Marlin 25-20 cartridge is now shown as Adapted to Winchester and Marlin Repeating Rifles.
In catalog No. 81, both are shown available loaded with Black powder, with smokeless powder (equaling the Black powder velocity), and the smokeless Hi-Vel loading... and at this particular point in time, with all versions using an 86gr bullet.
The 25-20 Winchester High Velocity cartridge loading using the 60gr O.P.E. bullet would not be introduced until after Olin/Western Cartridge Co. purchased the bankrupt WRA assets in the 1930's.
The 25-20 Hi-Vel loadings were never recommended for use in Single Shot rifles.