REGARDING HAMMER PULLBACK
Posted: February 18th, 2012, 1:46 am
The installed position of the hammer and strut with spring is a “fixed” position. By fixed, I mean that the spring load is so positioned to the hammer and strut that these parts will remain in that position with HAMMER DOWN. If the sear assembly and disconnector are removed the hammer will still be in the hammer down position, unaffected, by these parts removed. This is the hammers “at rest” position. Another way of saying it would be this is the hammers installed position center. This is why you can push the hammer forwards from the hammer down position just a little bit and it returns. Pull the hammer back and it returns. The hammer notch has to engage the sear security tooth to stop forward movement of the hammer. Push the disconnector down, moving the sear out of engagement, and you can push the hammer forward until it contacts the sear plunger, way forward of normal travel, and then it will spring back to rest. Sear tooth is out of the picture here doing this. The hammer has to rotate very slightly forward, from the at rest position, for the hammers’ first notch, security tooth, to make contact with the sear’s tooth.
Here are two scenarios concerning accidental discharges-safety disengaged.
1 ) Hammer and trigger. If the hammer is pulled back almost to the single action notch AND the trigger is pull back also to keep up with the backwards movement of the hammer, then the hammer can be released while the trigger is still back and the hammer’s entire force will be delivered forwards WITHOUT the hammer’s security tooth being engaged. This area of circumstance is very narrow, but the pistol could “snag” both the hammer and trigger during holster insertion and with the appropriate timing deliver an almost full hammer impact to the unguarded firing pin, no hammer security tooth to sear notch engagement, to stop any hammer to pin force. Without the hammer security tooth and sear tooth engagement the hammer would be much more venerable to an impact. Defunk noted this. I agree with Norm that this is not a half cock. It is hammer down or at rest position with some protection from hammer pullback and let off. From what I have read here, discharges start from 1/3 to ½ cocked.
2) Hammer only. So how does this pistol discharge with only hammer pull back, no trigger movement and the safety in fire position? The hammer is fixed on a large diameter solid pin with two substantial bearing surfaces into the frame. The hammer will not “jump over” the sear because of this robust mounting. The hammer is controlled by the very strong hammer spring. The sear is mounted with a very small pin and controlled by a very small, relatively weak spring. I do not think that the sear is somehow flexing and allowing the hammer to travel further forwards, not stopped by the security tooth on the hammer. So nothing is bending, jumping or flexing, at least to a great extent. What I believe is happening is that the stronger, faster returning hammer spring, is out returning the weaker, slower returning, sear spring. The hammer and sear are thus out of time and the hammer returns ahead of the sear. The hammer’s security tooth “misses” the sear tooth thus going forward into the firing pin. If there is some flexing of the pin mounted sear, I believe the timing problem starts this. These are just my thoughts. Still thinking……
Here are two scenarios concerning accidental discharges-safety disengaged.
1 ) Hammer and trigger. If the hammer is pulled back almost to the single action notch AND the trigger is pull back also to keep up with the backwards movement of the hammer, then the hammer can be released while the trigger is still back and the hammer’s entire force will be delivered forwards WITHOUT the hammer’s security tooth being engaged. This area of circumstance is very narrow, but the pistol could “snag” both the hammer and trigger during holster insertion and with the appropriate timing deliver an almost full hammer impact to the unguarded firing pin, no hammer security tooth to sear notch engagement, to stop any hammer to pin force. Without the hammer security tooth and sear tooth engagement the hammer would be much more venerable to an impact. Defunk noted this. I agree with Norm that this is not a half cock. It is hammer down or at rest position with some protection from hammer pullback and let off. From what I have read here, discharges start from 1/3 to ½ cocked.
2) Hammer only. So how does this pistol discharge with only hammer pull back, no trigger movement and the safety in fire position? The hammer is fixed on a large diameter solid pin with two substantial bearing surfaces into the frame. The hammer will not “jump over” the sear because of this robust mounting. The hammer is controlled by the very strong hammer spring. The sear is mounted with a very small pin and controlled by a very small, relatively weak spring. I do not think that the sear is somehow flexing and allowing the hammer to travel further forwards, not stopped by the security tooth on the hammer. So nothing is bending, jumping or flexing, at least to a great extent. What I believe is happening is that the stronger, faster returning hammer spring, is out returning the weaker, slower returning, sear spring. The hammer and sear are thus out of time and the hammer returns ahead of the sear. The hammer’s security tooth “misses” the sear tooth thus going forward into the firing pin. If there is some flexing of the pin mounted sear, I believe the timing problem starts this. These are just my thoughts. Still thinking……