Orca...you mean rimmed case. Rimfire is like a 22lr, 7.62x54R is a rimmed centerfire case. Acutally compared to the Enfields that use a rimmed case, the Nagant feeds better via a cartridge interuptor that keeps the rims of the cartridges from binding on one another.
Like the Enfield the Mosin Nagant and their cartridges are holld overs from the blackpowder era. Thats why they are rimmed. The 7.62x54R is ballistaclly close to the 308 so its good and unlike the 8mm or the 303 its still in service. The problem is with the steel cased laquer coated cases the ruskies and their allies use/used. The laquer burns off a nice sticky residue in the chamber of the gun and makes the nagant suffer from its sticky bolt syndrome, a problem that it has major issues with.
Other problems that make it less desirable than the mauser is the fact it has a multi piece bolt with removabel bolthead. This gives less strength to the design unliek the mauser with its one piece bolt. Combine that with the fact it only has 2 lockign lugs verus the Muaser 98's 2 with a thrid safety lug to prevent injury incase of bolt failure is an important deficency.
Also the Mosin Nagant does not have any gas vent holes like the Mauser so if you get a ruptured case or primer you get a face full of nast shrapnel and powder, the Mauser vents the gas away fromt eh shooter down into the internal magazine.
The internal magazine of the mauser is more reliable because by putting it inside it cannot be damaged by being thrown around by a soldier like the Nagant.
Also the Mauser is the second most widely produced rifle in the world, only slightly second the AK. Over 100 million Mausers were made for various militaries....then add all the sporting guns adn you have the most prolific arm of the first half of teh 20th century.
The Nagant would have a better argument if more countries used it. Only Russia/USSR and Finland used it. The Finns using them because they were part of Russia until 1917. The Mauser saw service in over 50 nations and was the inspiration for many other designs like teh 1903 Soringfield...a design so close that the US Govt lost a lawsuit and had to pay to use the Bolt, Charger Clip, and internal magazine because they were blatant copies of the mauser patent.
The Mosin is more comparable to the French Lebel, Mannlicher Carcano, and Enfiled. These were all its contemporaries. The 1891 Mauser is also comparable, however the performance of the 1893/1895/1896 family as well as the pinnacle 1898 Muasers are all superior in every way.