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Old 10-19-2012, 07:21 AM
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Dave Nash Dave Nash is offline
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Quote:
Originally Posted by bruno2 View Post
Wow!Now that's the kind of explanation I can appreciate. just twisted my arm A little I'm gonna take A hand full of 9.mm. to the shop & try it out. Greatly appreciated thanks for A great response!
Quote:
Originally Posted by bruno2 View Post
Is that why the the hammer is not completely concealed = Bobbed. ?still has 2 or 3 ribs to get a hold of?
“bruno2”:

Sorry for the delay in getting back to you.

The hammer you saw on the 5943 isn’t really “bobbed” as “bobbing” is more often associated with lopping off or significantly reducing the spur that is found on some hammers where it is used for manually cocking the guns to which they are attached into Single Action because it was felt that their original profile could snag when carried or be problematic for other reasons. That term is also used when that hammer spur is “bobbed” (or outright “removed”) on firearms that have been “converted” to double-action-only and it is no longer necessary. On the 5943, it is shaped differently from the start, for as discussed in my previous Post, this is a Double Action Only gun and there is no Single Action function or mode to it and, therefore, a spur isn’t needed and other criteria became the primary reasons behind the hammer design or profile.

The hammer on this gun needs a surface shaped to allow the slide to ride across it as it moves to the rear (and again to the front) as a component of the gun’s functioning when it is fired or cycled manually. That part of the shape allows for several things.

It provides enough contact with the slide so that in combination with the spring to which it connects in the backstrap/butt, the hammer affects (resists or slows down) the slide during that movement (after the gun is "fired") to the degree desired (or needed) by the “engineering” of the gun.

It also provides the right shape so that when the gun is “fired” the hammer makes the desired amount of contact with the firing pin that is contained within the slide.

And finally, it provides the correct amount of mass so that when the gun is “fired”, the hammer combines with the force generated by the spring to which it connects in the backstrap/butt to strike the firing pin in the slide in such a way that it can detonate the primer of the chambered cartridge.

The “ribs’ (your word) are there for function and engineering reasons in order to allow its final shape to permit those three things and more; including, again through overall engagement with the slide, helping the hammer (through the surface machined on its other end) to come to rest in a fireable condition (after such back and forth cycling of the slide is accomplished either by "firing" or manual handling of the slide and frame), awaiting the user to pull the trigger if he or she chooses.

They are not there for the user to “get a hold of” for there is no reason to do so as there is nothing to be had by doing so. If the mechanism needs to be reset (other than by firing), it is purposely designed to reset by manually “cycling” the slide on the frame.

When the Double-Action Only concept was developed, a number of different approaches were considered.

While I personally preferred one that utilized a conventional hammer profile (albeit flat to rear face of the slide like on a 469/669/6904/6906) and offered a longer, more K-Frame-revolver-like stroke, after much studying, testing and experimenting, it was decided to go with the one you probably "see" (experience) in your gun. It employs a shorter trigger stroke that many people preferred and even I acknowledged would “fit” a larger number of people than does the more conventional length that I happened to like and that had been seen as the first stroke on many S&W semi-automatics for decades.

In order for the gun to be in that “fireable” condition that I mentioned earlier, it needs to have that lower surface that I mentioned properly engaged. In that condition, it was decided early on, that the hammer on these shorter-stroke (length) guns would have to “rest” or “sit” in a position further to the rear than it did in the case of the more familiar and more conventional Traditional Double Action guns. As such, the slide and the frame on these guns were extended to the rear in the standard production models in order to better encapsulate the hammer when it was in this location.

It was felt that this would minimize concerns that some people, unfamiliar with the mechanism, might have if they thought the gun was “cocked” in the manner of a gun capable of single action firing (or even “half-cocked” as seen on those pistols that employed a half-cock notch for other reasons). This encapsulation would also help minimize people’s attempts to reset the mechanism by manipulating the hammer instead of manually cycling the slide on the frame. This physical difference was why I mentioned the differences in slide and frame lengths as related to possible issues with holster retention and safety straps designed for either Double Action Only or Traditional Double Action versions of the 5900 Series in my first response.

It should be noted that in addition to a number of various trigger-stroke-length guns that were floated out in the public’s (generally Law Enforcement’s) hands for feedback, there were also Double Action Only models sent out for testing (and possibly for sale when they were through) with the shorter slides (and frames) of the original Traditional Double Action guns fitted to them that had all kinds of filler plates installed into the manual safety/decocking lever recess cuts in their left sides. It was an interesting time to say the least and I am sure that some of those early guns are still out there; either confusing people or making them wonder what they have.

While I am sure that you learned all about the action of the gun you mentioned first hand (that is, if you had the chance to test fire that pistol as you indicated in your earlier message), I still hope that at least some of this helps you out and perhaps answers some of the questions that you and other people reading this thread have about this Model in general.
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