Redsetter wrote on Mar 2^nd, 2017 at 9:29am:

It shows up in the Aug 1895 WRA catalog No.55, and when you go from the 1892 Rifle section to the ammunition section of that catalog, you see the 25-20 Winchester Model 1892 cartrige, AND the 25-20 Marlin cartridge listed.
Now you get to ask yourself if they were the same cartridge with a different name only because they were loaded with different bullet shapes, like with the 32 S&W Long / 32 Colt New Police cartridges, and the 38 S&W and 38 Colt New Police cartridges, etc, or not.
The Ideal handbooks show moulds for calibers having Winchester shaped bullet noses and Marlin shaped bullet noses.
WRA loaded the 32-20 Win with a 115gr bullet, while the 32-20 Marlin was shown using a 100gr bullet.
People had their own particular preferences and notions back then too.

The .25-20 Marlin did come out in the 1889 Marlin, and from the old Marlin catalogs I have it was offered in 1893 in the 1889. There were only 25 or 30 Model 1889's built in the .25-20M, and they were all special order guns, not standard 1889's. The 1889 stuck around for awhile after Marlin brought out the 1894 Model in the same caliber, but likely any sold after the 1894 hit the market in mid year of 1894 were assembled from leftover parts.
Marlin also came out with their .25-36 Marlin caliber first in the 1893 Marlin. But shortly afterward Winchester came out with the .25-35 which was slightly changed shoulder that allowed it to fit the 1893 Marlins, but the .25-36M would not fit the Win. .25-35 guns.
Marlin had a very close relationship with UMC and Remington, so they didn't need their own ammunition manufacturing facility. Any cartridges that were proprietary were introduced by UMC first. But Winchester did also sell the Marlin proprietary ammo, as I have boxes of .25-20M and .25-36M that are Winchester made.
Eventually Marlin dropped both of their proprietary cartridges and chambered their guns for the Win. cartridges.

The 1923 Rem-UMC No. 107 catalog lists the repeater " 25-20 WINCHESTER, MARLIN AND REMINGTON " cartridge.
The 1910 Rem-UMC catalog lists the repeater " 25-20 WINCHESTER & MARLIN " cartridge.
You'll have to go back before 1910 in Rem and UMC literature to see if the 25-20 Win and 25-20 Marlin cartridges are ever listed separately by Rem or by UMC.
 
Additional note: 
Both above Rem-UMC catalogs list the 25-20 SS as the " 25-20 STEVENS AND WINCHESTER SINGLE SHOT " cartridge,
and
both above Rem-UMC catalogs list the 22 WCF as the " 22 WINCHESTER SINGLE SHOT " cartridge.

marlinguy wrote on Mar 2^nd, 2017 at 8:11pm:


What they really did, if there was no difference in the dimensions of the two cases, was merely change the caliber marking on the brl. to de-confuse their customers!

BTW Looking at that bullet, I'm thinking that it was swaged, not cast.  Swaged straight-sided, then fed between rollers to create the lube grooves.  The ridges at the bottom of the grooves would be the result of the rollers having "teeth" to prevent slippage.  The whole process would be much faster and cheaper than casting.

coljimmy wrote on Mar 2^nd, 2017 at 11:50pm:


I have a dozen Ideal tools marked Marlin Firearms Co. on them. But they are also marked Ideal on them. Interestingly some of the tools I own that are MFAC marked are .25-20 and .25-35. Those tools are dual marked for calibers. They are marked .25-20 WCF and .25-20 M. The other is marked .25-36 M and .25-35 W below that.

uscra112 wrote on Mar 2^nd, 2017 at 11:51pm:


I've always assumed that most factory-made cartridges were loaded with swaged bullets not only for considerations of time & cost, but to produce more uniform bullets.