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1911 Thumb Safety


pisgahrifle

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Yesterday I had a "discussion" with an individual who strongly asserted the the 1911 was unsafe because the thumb safety did nothing but block the trigger bow and prevent the slide from moving. I tried to explain that the thumb safety phisically prevented movement of the sear in addition to keeping the slide locked. I was then informed that this was only on series 80 guns (WTF?) and that the thumb safety had nothing to do with the sear, and it was heavily implicated that due to my relative youth I had no idea what I was talking about. I know how the sear-disconnector-trigger-hammer-series 80 safety parts group works, but I've never thought about how the thumb safety works other than when engaged it blocks the movement of one of these components. So, two questions:

1. Was I not right, or does the notch in the safety block the hammer?

2. Where can I find that STI animation program where you can see how the parts physically engage in a Mac format?

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When the thumb safety is engaged, the part of it that's inside the frame pivots up into position right behind the bottom part of the sear... the part that's below the pivot. If the safety is properly fit, it prevents the sear from moving at all. Since the sear can't move, the hammer can't fall, so the gun won't fire.

The GRIP safety prevents the trigger bow from moving rearward, but has absolutely nothing to do with the sear.

It's been a long while since I've had a series 80 pistol apart, but if I remember correctly, the only difference in the way any of this works is this... an extra piece of steel is engaged by the trigger, and pivots about the same pin as the sear. When this piece pivots, the upper part of it pushes on a plunger in the slide, which then allows the firing pin to move. The downside of this, aside from just the fact that there are added parts, is that since they are activated by the trigger, they have an effect on the trigger pull. Many people claim it can be minimized to where it is unnoticable, or nearly so.

Kimber put a different twist on the series 80 firing pin safety, by using the grip safety to activate it rather than the trigger.

Art

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As Benny and aclundwall say the safety blocks the sear and the slide. Also aclundwall's description of the series 80 parts is correct. I don't know about the STI program, however Jerry Kuhnhausen's book 'The Colt .45 Automatic A Shop Manual' shows the relationships.

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I had a "discussion" with an individual who strongly asserted the the 1911 was unsafe because the thumb safety did nothing but block the trigger bow and prevent the slide from moving.

WOW, all I can say is WOW

I was then informed that this was only on series 80 guns (WTF?) and that the thumb safety had nothing to do with the sear, and it was heavily implicated that due to my relative youth I had no idea what I was talking about.

Clearly this statement came from someone who has many years of experience.

The same year over and over and over again. WOW

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Reminds me of a discussion a few years ago where a 40 year old man, owner of a Desert Eagle, said such gun was blowback ( ! ) operated. When I said it was gas operated, I was quickly dismissed by people in the room as a 17 year old "brat". Needless to say, I graciously left the room.

I feel your pain on discussing subjects with people who have sawdust where their brains should be. And I'm not referring to being ignorant about a subject (such as 1911 thumb safety inner working, or a certain gun's mechanical operation), but to the closed mind "I'm better/wiser than you" attittude.

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