Miroku makes some superb rifles.
They are the "jap" in "japchester" and the sad fact is that they make better Winchesters than Winchester has since the whole USRAC thing happened. In fact, they've made better Winchester lever actions than Winchester has since 1964.
They are also the folks who made the Winchester and Browning Model 52 B and 52C re-issue sporters in the late 1980s and I don't hear people complaining about the quality of those rifles either. They were arguably the best production .22 LR sporters ever made.
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I agree with the comments on the 1873 action in general however. It is a toggle link design and the head space tends to grown with a steady diet of .357 Magnum ammo.
The Model 1892 however is a smaller version of the Model 1886 and as such it is a very strong action that stands up well to the 65,000 psi .454 Casull.
Winchester (Miroku) still makes Model 1892s but they are pricey.
Armi Sport - Chiappa makes a very authentic 1892 copy and it's sold under a number of brand names. The details vary a bit by brand, but they all function very well, and the fit and finish is excellent. They are slick and ready to tun our of the box and make great shooting rifles and carbines.
Rossi also makes a near copy of the Model 1892 as their Model 92. They have more experience with the design and modern pistol cartridges than any other maker and after nearly 50 years they have a very fine tuned design. The lines of the receiver vary a bit from the original and it incorporates a coil hammer spring rather than a flat spring, and has some other changes such as a firing pin safety (that can be removed and plugged if you prefer).
Rossi's have very nice exterior metal polish and finish once you get the preservative off, but you'll find some tool marks and general grit inside, so they benefit from some general clean up and polish. Stevesgunz.com sells a DVD showing you how to slick up the action and sells a lighter ejector spring and a metal magazine follower. The lighter ejector spring will give you the single biggest improvement in smoothness of the action and will stop it from ejecting the empty brass 6 ft over your head. But since you've got it apart to change the spring it's not much more effort to polish the cartridge lifter detents and the few other areas that benefit from some polish.
The stock finish wasn't bad in the past, degenerated to something akin to shoe polish for a few years and now is back on the upswing. However, the base finish makes a great start for a tung oil or tru-oil finish. The first couple coats will dry slow when applied directly to the original finish as the two integrate the but rest dry down in the normal length of time. The results are very nice.
Price wise the Armi-Sport Model 1892 will run you around $900-$1000, while a Rossi will run about $500.
You can get the Rossi in blued, stainless or color case hardened finishes.
Here are my 20 and 24 inch rifles after some Tru-oil on the wood - knocked back to a semi glass with 0000 steel wool.
This is my 20" Model 92 rifle with CCH finish:
Both rifles are in .357 magnum and with the Lyman 17AHB front sight, Marbles Tang Sight and a Merit #3 or #4 adjustable aperture are capable of 5 shot 2" groups at 100 yards with Federal's 158 gr JSP load (1810' per second in the 20"), or with hand loaded 125 gr Hornady XTP (2170 fps in there 20" , 2210 fps in the 24").
Here is my 24" Armi Sport Model 1892 Takedown: