My goodness, so many opinions.
As stated, any close replica of the Colt Single Action Army should be limited to SAAMI Max pressure of 14,000 PSI. This will include any Italian imports whether they are made by Uberti or Pietta. Cimarron rifles are manufactured in Italy by Uberti. Yes, all firearms manufactured in Italy must go through strict proof testing, and the pressure levels Italy uses are slightly higher than American SAAMI standards. Bottom line, do not use ammunition that exceeds the pressure the firearm was proofed at. No, you do not have to limit yourself to 45 Colt Cowboy loads. There is no official standard for pressure with Cowboy loads, but generally manufactured ammunition that says Cowboy ammunition on the box will generate slightly less pressure than the SAAMI Max pressure standard.
Rifles: The 1860 Henry, Winchester Model 1866, and Winchester Model 1873 all had what are called Toggle Link actions.
This is what the action of a Winchester Model 1873 looks like with the side plates removed. The Henry and Model 1866 actions are basically the same, but the 1873 side plates are easier to remove than on the other two, hence I used the 1873 to demonstrate a Toggle Link Action. The action is in battery in this photo. The links are extended, holding the bolt in position. If the hammer was cocked and ready to fire, the links would look the same. Notice there are three pivot points for the two links. One at the front is connected to the bolt, one at the rear is pinned to the frame, and one in the center is connected to an extension of the lever. There is another set of links on the other side of the frame exactly the same, except they are a mirror image of this set.
In this photo, the lever has been pushed all the way forward. The extension of the lever has folded the links, pulling the center pivot down and rearward. When the links folded, the front pivot pulled the bolt back, and the bolt extension cocked the hammer. The angled piece, called the Lifter Arm, has raised the brass Cartridge Carrier to the position it needs to be in for the bolt to shove a new cartridge into the chamber. The top of the brass Carrier can be seen peeking out of the top of the frame. Here is the thing about Toggle Link rifles. There are no locking lugs as there are on most modern rifles to keep the bolt in battery when a cartridge fires. All that is keeping the bolt from jumping back is the fact that the three pivot points of the links are lined up. Actually, when in battery the links have a slight over travel, with the center pivot slightly out of line with the other two. But there is no positive lock up of the links as there is with a modern rifle. If the action was not completely closed, and the trigger was accidentally pulled before the links finished lining up, the thrust of recoil would shove the bolt back forcefully, and the lever would swing forward forcefully. I have seen it happen at CAS matches when a shooter did not keep his finger off the trigger until the action closed. At the bottom of the frame behind the trigger a small piece is projecting downwards. This is a lever safety device. It prevents the trigger from being pulled until the lever has closed completely. You can see another part of the lever safety directly behind the trigger. When the bolt closes, it pushes the lever safety up out of the way, allowing the trigger to be pulled. This is not a modern Lawyer Driven safety device, Winchester engineers included it in the design around 1878 or so if memory serves, because they recognized the potential for injury if the trigger was pulled when the action was out of battery. Interestingly enough, modern replicas of the 1860 Henry and 1866 Winchester, true to their historical predecessors, do not include a lever safety.
Don't get me wrong, Toggle Link rifles are good rifles, when used the way they were designed. But notice frame is basically a skeletonized frame. Not a whole lot of metal there to absorb the punishment of heavy recoil. I shoot a replica 1860 Henry myself in CAS, but I only shoot it with Black Powder loads. I would not hesitate to shoot it with modern SAAMI spec ammunition, but I certainly would not shoot any hot stuff in it. Yes, Uberti chambered the 1873 rifle for 44 Magnum a few years ago. I had a chance to inspect one, and could not detect any material differences between it and one chambered for 45 Colt right next to it. Yes, it had to have been proofed the Italian standards for 44 Magnum. But bear in mind, proofing only subjects a firearm to one proof load, usually around 30% higher pressure than the Max pressure. I have no confidence a 44 Mag '73 frame would stand up to long term punishment from standard 44 Magnum ammunition. Years ago a friend bought a used Uberti '73 chambered for 357 Mag. He brought it back to the store when he found a hairline crack in the frame. No one could say what cracked the frame, but he was not going to take a chance with a '73 with a cracked frame.
The Winchester Model 1892 was designed by John M Browning, the dean of American gun designers. It is basically a scaled down version of his earlier Model 1886 lever rifle, which was chambered for longer cartridges such as 45-70. The '92 has a pair of locking lugs that ride in slots in the frame and bolt.
When the lever is pulled forward it pulls the lugs down and out of their slots in the bolt. This frees the bolt to move backwards. You can see the slots for the lugs in the bolt in this photo. Like most lever action rifles, when the bolt moves back it cocks the hammer for the next shot.
Unlike the Toggle Link rifles, the carrier in the '92 tilts upwards to present a round to the chamber. In this photo the bolt is about to shove a fresh round into the chamber. Although all of these photos have been of original Winchester rifles (notice the 44 WCF cartridge call out) the modern replicas all function exactly the same, whether they have been made in Italy, Japan, or wherever Rossis are made today.
So. Bottom line. the '92 is basically a stronger design than a Toggle Link rifle. When first produced the 1892 Winchester weighed one pound less than a 1873 of the same caliber and barrel length, and it was less expensive to manufacture than the '73. Not telling you not to buy a Toggle Link rifle, I love my Henry, but do be aware of their limitations. Modern 1892 replicas are routinely chambered for 44 Magnum, and one brand chambers it for 454 Casul. I do not own a '92 chambered for 45 Colt, it was never chambered for that cartridge until sometime in the 1980s and all of mine are antiques chambered for 44-40 or 38-40. I did win a Rossi 1892 in a raffle once but never fired it. I sold it to help pay for my Henry. Straight out of the box the action was a bit stiff, but it would probably wear in in time.
The 1894 Winchester chambered for 45 Colt? The 1894 is a longer action, designed for longer cartridges such as the 30-30.
There is a single locking lug on the '94, all the way at the rear of the bolt. Like the '92, the lug rides in slots in the frame.
To get enough lever throw for the longer cartridge, the '94 has a hinged floor plate that moves down when the lever is pushed forward. The hinged floor plate pulls the locking lug down, allowing the bolt to move back and cock the hammer.
Chambering it for 45 Colt is a compromise. I knew one Cowboy shooter who had a '94 chambered for 45 Colt and it was a jammamatic. I would not spend my money on a '94 chambered for 45 Colt.