I am interested in this gun however, I dont understand how it can be safely carried with a round in the chamber and still be considered single action. If it posesses a true "single action" trigger with only a grip safety, it seems like a signifigant departure from the orthodoxy concerning the carry of single actions.
All a gun needs to be, in order to be a single action, is a hammer that has to be manually cocked, and is released by pressing the trigger. That, by definition,
is a single action -- the trigger performs
one action: releasing the hammer (or striker, in some), not two: cocking
and releasing the hammer/striker. It doesn't need a thumb safety in order to somehow qualify.
The fact that the vast majority of single actions have thumb safeties is merely indicative of the fact that most people perceive a need for them, but a gun is still a single action if it has to be manually cocked before firing. There have been single action semi-autos before that had no manual safeties (e.g. the Polish VIS-35 Radom [that thing that looks like a 1911-style thumb safety is nothing more than a take down latch], and the Russian TT-33). For that matter, on the original Model 51, the thumb safety was advertised by Remington as being there as an extra measure of safety for those who wanted it, but they also said the gun could safely be carried with a round chambered, and the user relying on the grip safety only. I've carried one that way for years.
Most people see a need for a thumb safety on a single action auto because of the short, light trigger pull, and the short amount of take up. DA revolvers and autos are not perceived to need them simply because the longer, heavier pull provides the needed margin of safety to avoid negligent discharges (as long as you remember to exercise proper gun handling habits). Guns like the Glock which are not quite one nor the other, mechanically, still have no manually operated safety because again, the length and the weight of the trigger pull are thought to provide an adequate margin of safety. The old Model 51 had a trigger pull in the 5-7 pound range (which is about what Glocks come with today), and enough take up that a manual safety wasn't considered absolutely necessary. No doubt Remington feels the same way about the R51, and the current demand for modern pistols with no manual safeties no doubt led the company to rely on the grip safety, and a slightly heavier, longer SA trigger than most 1911s have, and leave it at that.
. It'd be the 357 K-frame all over again 
). Aside from what are mostly marketing blunders thus far, it still seems unlikely the gun can be utterly terrible out of the gate. That said, I still wouldn't pre-order for one sight unseen --that's truly asking for trouble. A quick once-over to make sure the gun feeds snap caps and actually has a working striker and safety, and doesn't bind up when cycled will allay any fears of "uncertainty" I might have. If it can do those things, it can at worst be "imperfect" rather than unworkable.
