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  #11  
Old 05-27-2019, 06:14 PM
DougS DougS is offline
 
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Quote:
Originally Posted by New2Brass View Post
What holds the trigger back to initially fire?
How do you stop firing?

The receiver bridge may absorb all the firing pin energy
The trigger will hold the hammer back when it is not pulled back by the shooter. The sear will engage the hammer if the trigger is still held back and hold it. When the trigger is released the hammer transfers back to the trigger hooks. So, if the sear is missing, the hammer will continue to follow the bolt as long as the trigger is held back. Release the trigger and the hammer hooks will engage the trigger hooks.

Take your trigger group out of the rifle and try it. Pull the trigger and keep it held back and then bring the hammer back while the trigger is still back. Note that the hammer engages the sear, not the trigger. No sear, and it can't catch on anything. Release the trigger and recock the hammer. Note it engages the trigger hooks, not the sear.

Yes, the receiver bridge may impede this. I'm not suggesting someone try this, only that this may be how it was accomplished in the past.
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  #12  
Old 05-27-2019, 06:27 PM
meplat meplat is offline
 
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Doug,

The carbine's hammer has no "hooks" (unlike the hammer of Garand-like rifles).

This site has a good animation about 75% down the page of the action:

http://www.uscarbinecal30.com/operation.html



If you can get the animation to work it's VERY informative. The original QuickTime versions were totally awesome in that you could "play" them manually forwards and backwards by means of a slider at your own speed so you really see how things work. But unfortunately, unless you saved them to use with your QT viewer offline, they're gone.

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  #13  
Old 05-27-2019, 06:57 PM
meplat meplat is offline
 
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NOTE ADDED IN PROOF:

If the rear portion of the oblong sear pin hole is filled (welded & redrilled), then the sear is set back a bit in the housing as it is in its normally cocked position.

When trigger is pulled in a carbine bearing such a part, the sear disconnects from the hammer (as usual) but will remain so until the trigger is released (NOT as usual). This would allow "uninterrupted" action in the field by an auxillary sear, say tripped by the firing pin, to release the hammer. So some additional hardware more creative than can be discussed here would be needed to make things run, safely.

A post in this forum appeared a while back regarding just such a "strange" sear

http://forums.thecmp.org/showthread.php?t=155867


Last edited by meplat; 05-27-2019 at 08:05 PM.
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  #14  
Old 05-27-2019, 07:02 PM
New2Brass New2Brass is offline
 
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Quote:
Originally Posted by meplat View Post

If you can get the animation to work it's VERY informative. The original QuickTime versions were totally awesome in that you could "play" them manually forwards and backwards by means of a slider at your own speed so you really see how things work. But unfortunately, unless you saved them to use with your QT viewer offline, they're gone.

We just paid for Vimeo to replace the Quicktime, which was no longer supported. The animations should work. If you have issue please let me know what browser you are using.

First is the picture followed by the animation. You have to click play for it to start.
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  #15  
Old 05-27-2019, 07:05 PM
meplat meplat is offline
 
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The old QT versions you could "play" at your own pace, just by sliding the "scroll bar" up and down manually. Start, stop, backwards, forwards, frame by frame, variable frame rate, any way you could imagine. Way cooler than Vimeo.


Last edited by meplat; 05-27-2019 at 07:09 PM.
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  #16  
Old 05-27-2019, 07:09 PM
New2Brass New2Brass is offline
 
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Quote:
Originally Posted by meplat View Post
The old QT versions you could "play" at your own pace, just by sliding the "scroll bar" up and down manually. Start, stop, backwards, forwards, frame by frame, any way. Way cooler than Vimeo.

I understand and agree.

Quicktime was no longer supported so they would not play

We had no choice but to buy the Vimeo

To add: in the settings (little gear logo) you can slow down the animation rate to better observe.

Here is a picture of a modification similar to the Conway conversion that required a hole to be drilled in the trigger housing.
http://www.uscarbinecal30.com/forum/...topic3188.html

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Last edited by New2Brass; 05-27-2019 at 07:37 PM.
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  #17  
Old 05-27-2019, 07:32 PM
meplat meplat is offline
 
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Seeing something so incredibly simple like this, I often wonder why Sampson and Hamisch ultimately designed the mechanical monstrosity we all know and love. Perhaps a need for originality in the face of prior art?

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  #18  
Old 05-27-2019, 07:41 PM
New2Brass New2Brass is offline
 
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I would guess it had something to do with the cylclic rate, safety, or reliability.
Note how the hammer hits extra piece which in turn hits the firing pin.
This may allow out of battery firing?

Do not forget the Winchester had its own design and I think Springfield Armory had a design as well.
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  #19  
Old 05-27-2019, 07:45 PM
meplat meplat is offline
 
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The piece the hammer hits in the picture is the auxillary sear. The tail of the firing pin, when the bolt rotates into battery (clockwise as you shoot), pushes the sear off the hammer "lug" so the hammer can fall. I'm sure there's enough clearance on the sear's front side so than when the hammer lug gets "caught" again after firing prior to the next round, it's "bump" into the sear doesn't reach the firing pin.

I've never handled one of these relics in real life, but I don't imagine much force is needed to push way the sear at the top, so there wouldn't be much if any real inhibition of the bolt closing or rish of an OOB discharge. I'd be interested to know the actual force required though ... for academic purposes only

Yes, many "designs". I've come across quite a few since my journey started almost 10 years ago. Still wonder though


Last edited by meplat; 05-27-2019 at 07:57 PM.
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  #20  
Old 05-29-2019, 09:17 PM
DougS DougS is offline
 
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Quote:
Originally Posted by meplat View Post
Doug,

The carbine's hammer has no "hooks" (unlike the hammer of Garand-like rifles).

This site has a good animation about 75% down the page of the action:

http://www.uscarbinecal30.com/operation.html



If you can get the animation to work it's VERY informative. The original QuickTime versions were totally awesome in that you could "play" them manually forwards and backwards by means of a slider at your own speed so you really see how things work. But unfortunately, unless you saved them to use with your QT viewer offline, they're gone.

Note that I responded to making the M1 RIFLE an automatic, not the carbine.
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