We've been here before. Yes, there are a few people who really like the top-break action and would probably buy such a gun. (I am not discussing the Schofield or similar "repro" guns, which sell on nostalgia and handle only low power rounds anyway.)
But the fact is that in a revolver, the top strap takes most of the strain of firing, and that any joint in it will continually take pressure and expand. The joint must have some space to move, or else it couldn't open. As the gun is fired, the metal at that point will compress and the gap will expand. Wear from opening and closing will add to this. Whether the expansion is fast or slow depends on the metal involved, the type of lock and the power of the cartridge, but it is unavoidable.
I think it would be possible to make a modern top-break revolver that could handle any reasonable range of power; I have not seen the Russian gun, but have no doubt it will work OK, at least for some limited use.
But I just don't think the market is there. Revolvers in general are now very much the secondary handgun type, and I doubt introducing a new form would improve matters. In addition, the top break system is not well thought of, mainly because of the old guns that could not even stand up to .32 S&W pressures.
In the old days, S&W sold its top breaks because they were faster to (re)load than the Colt SAA and the smaller solid frame revolvers by Colt and others. But today, the only advantage of the top-break is that it can be emptied a smidgen faster than a swing-out cylinder gun. I don't think that advantage is enough for a gun company to invest a million bucks in setting up production.
Of course, if enough top-break fans were to bombard say, S&W, with orders, accompanied by cash deposits of around $1000 each, I think the company might reconsider.
Jim
