Help Fitting 1911 Thumb Safety

Discussion in 'Gunsmithing and Repairs' started by carnaby, Jan 6, 2007.

Thread Status:
Not open for further replies.
  1. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    I borrowed the 1911 cutaway pic to show the problem I'm having

    1911_cutaway_thumb_safety_blocking_.jpg

    I replaced the hammer and sear on my TRP with Ed Brown components which work great in every other respect except that it takes some force to get the thumb safety all the way up with the hammer at full cock. I had a good look while putting the components together with the grip safety out and saw that the thumb safety, as labeled 1 in the picture, is bumping into the hammer at the point labeled 2 in the picture.

    The question I have is how do I fix this problem as safely and simply as possible? It seems like I should just file off the back of the thumb safety post until it clears the hammer, but I want to make sure before I proceed.
     
  2. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    Safety Woes

    First...The thumb safety doesn't have anything to do with the hammer. It blocks only the sear. Assemble the gun without sear or disconnect...pull the hammer to the full-cock position and hold it. Engage the safety, and let go of the hammer. It'll wipe the safety off as it falls.

    You probably need to take more off the single point of the safety that bears against the sear leg. Do a quick test.


    Pull the hammer just a wee bit past full cock and hold it there while you engage the thumb safety. The safety should engage a little easier. With the safety in the "ON" position, lower the hammer. Then, while watching the hammer closely, thumb the safety to the "OFF" position. If the hammer moves forward, you need to take a little more off the sear blocking point.
     
  3. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Thanks Tuner. I know the safety isn't supposed to interfere with the hammer, only the sear, but it is. I'll give your recommendations a try and see what happens. :)
     
  4. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Alrighty, I had a go at it and this was the result:

    1. pull the hammer past full cock. Thumb safety cannot be engaged.

    2. At full cock, thumb safety takes extra force to push into position. If I pull back on the hammer then, it stays back. When I let the safety off, the hammer moves forward.

    So what is the method to fit these parts together? Take material off the safety where it contacts the hammer, or where it contacts the sear, or both?

    Thanks :)
     
  5. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Actually, it is as you say. If I only pull it a tiny smidge past full cock, it is *slightly* easier to engage the safety as in I can barely manage it with my thumb and a normal grip. If I don't do that, then I can't manage it at all without using my other thumb to help.

    And it does move forward after that when I release the thumb safety.

    So how much and where do I take material off the sear? I have a good idea that it's where the sear contacts the thumb safety in the first image above.
     
  6. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    re:

    Assemble the gun without the grip safety so you can see the point on the safety that blocks the sear, and where it's in a bind. With the safety oriented as it would be in the gun, it's the bottom point. Take a little off that point...a LITTLE...and check it. Repeat until the safety will engage smoothly...decreasing the amount of removal as it gets closer.
     
  7. HSMITH

    HSMITH Member

    Joined:
    Dec 26, 2002
    Messages:
    4,933
    Use a marker, blue or red, color the contact points on the sear and the safety. If you aren't sure where they are rubbing color the whole things. Assemble, operate the safety, disassemble and look at where they are rubbing. Take a couple LIGHT passes with a file, and do it again. You might do this 25 times, but if you get in a hurry you will have a brand new safety in the garbage can and start over.

    I like to have just a tiny bit of rubbing between the safety and the sear. When the safety is applied it goes on easily, but the sear is locked to the hammer firmly. Just my preference.
     
  8. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    That did it, thanks!

    The safety seems to be of softer stuff than the sear, so it was worn back where it needed to be stoned. I gave it a couple passes and voila!

    Thanks again :D
     
  9. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    re:

    Don't break out the champagne just yet...

    Cock the hammer and engage the safety. With the gun in a firing grip, pull the trigger with about double the amount of force needed to fire it, and release. Hold the left side of the gun to your ear...at the safety...and gently pull the hammer back just a wee bit past full cock. Don't let it touch the grip safety. If you hear a tiny "click" you've taken too much, and the safety isn't fully blocking the sear. The "click" is the sound of the sear resetting into the hammer hooks. If you don't hear it, you're golden.

    Oh yeah...Be sure that the gun is empty when ya do this test. :p
     
  10. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    No click,

    but when I pull back on the hammer past half cock, it sticks a little and doesn't return on its own all the way back to full cock. Is that acceptable? It's still a little tough to pull the safety on, just not as bad as before, and a totally acceptable force, really.

    What do you think? :confused:
     
  11. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    Think?

    I think that if the hammer won't return...and ya wipe off the safety...the hammer'll move forward. It means that ya gotta take a mite bit more off the point.;)
     
  12. HSMITH

    HSMITH Member

    Joined:
    Dec 26, 2002
    Messages:
    4,933
    Color it up, all the way around the part that sticks inside of the frame. It might be hitting on the front too. Lift the safety lever just a hair, cock the hammer slowly from all the way down and past the halfcock notch. Does it hit the safety?

    Lots of the new safeties will hit the hammer unless the safety is ALL the way down.
     
  13. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Tuner, help!

    OK, I put the parts from the TRP into the Black Stainless. This worked fine and no click.

    Now I futzed with them, no modifications, but just tried the parts from one gun back in the other and so forth. Now, with the black stainless using the hammer and sear from the TRP, I get the click! Argh! It is there every time, but it takes just the tiniest amount of pressure on the hammer to get it. What do I do? These parts all worked before and I've made no mods to them. I did fart around with the trigger/hammer/safety three prong spring thingy. Could that have done it? That might be what I'm hearing, but I'm not sure.

    Help!
     
  14. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    Click

    The "click" means that the point on the safety isn't long enough to completely block the sear, and there's really nothing to do except get another safety. On pistols that have collector value, and replacing an original part with one that isn't correct would detract from the originality, I've sometimes used a hammer to stretch the point a little...just to get it into functional condition...
    but this is only a field expedient repair that's acceptable in an emergency...or when the pistol won't be heavily used...or to preserve the originality of a collectible gun. It's also questionable with a cast or MIM safety as to whether it will last very long, since the stretched portion of the point is very thin...and those materials don't do too well in thin cross-sections.

    Just FYI...In original pistols with full-length, captive angle hammer hooks, the Army Ordnance Department accepted .005 inch of sear movement as serviceable. When hammers with square, shortened hooks are used, no movement is acceptable or safe.

    Looks like another thumb safety is on your shoppin' list...
     
  15. Old Fuff

    Old Fuff Member

    Joined:
    Dec 24, 2002
    Messages:
    23,907
    Location:
    Arizona
    With the exception of USGI pistols, and exact civilian counterparts, safety locks (manual safeties) have to be individually fitted. The old service pistols had 5 to 6 pound trigger pulls, and today gunnies aren't satisfied with anything over 4 pounds with a crisp break. Cutting the hammer hooks down and using a sear with too much break away angle is a sure way to compromise the safety lock, unless like Tuner says, movement when engaged is zero, not "almost zero."

    Most of the 1911's being made today are not weapons, they're over-accessorized target pistols, with a rail under the dust cover. Calling them a "combat pistol" doesn't make them one.

    Basics should come first, cosmetics and gadgets second - if at all. :scrutiny:
     
  16. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    I just wonder why it started doing this when I didn't modify anything???

    It's more of a *ting!* than a *click*. Is it possible that it's the spring catching on something? It is repeatable, i.e. pull the trigger hard, touch the hammer *ting*, repeat without doing anything else different.
     
  17. Old Fuff

    Old Fuff Member

    Joined:
    Dec 24, 2002
    Messages:
    23,907
    Location:
    Arizona
    It is possible, but not too probable that a burr on either the safety or sear made it seem like things were right when you first installed the parts. Then moving the safety on and off, combined with pulling the trigger hard, was just enough to cause the condition you now have. This might have been aggravated when you moved the parts around in different guns.

    Today most of the pistol makers buy the parts they use to build guns, including frames, from different suppliers. These parts - frames included - don't always meet USGI blueprint dimensions, including pinhole locations. This makes it almost impossible to make "drop in" accessories that truly do drop in, especially when it comes to something like a sear/safety lock fit in pistols that often have reduced hammer hooks and modified sear angles.

    What is on the market today is a far cry from your grandfather's .45....
     
  18. RogersPrecision

    RogersPrecision Member

    Joined:
    Nov 22, 2003
    Messages:
    588
    Location:
    n az
    carnaby,
    I have read both of your posts.
    If this offends you so be it, but.........
    You have been given good advice and good instructions, yet you are still clueless.
    It is time to seek the help of a professional.
    Do not risk the health of yourself and others in the pursuit of stubborness.
     
  19. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    I appreciate the advice, Rogers, no offense whatsoever. I'm pretty sure I understand what's going on, I'm just being anal about fine details. I'm a Ph.D. in mechanical/aerospace engineering and do a lot of mechanical design work, for what that's worth.

    I also appreciate all the info I've been given. I'm considering getting some professional help, but I think things are OK. The fit and function of the TRP with the Ed Brown components is now perfect, and I'm just having the funny new issues with the other Springy.

    It's just strange that I had the other springy together with the TRP components, checked and rechecked a zillion times, took it to the range and all functioned fine. Now that I took them apart and put them back together with ZERO modifications to the parts EVER, it does the click thing. I wonder if maybe I got the sears mixed up between the two guns. I'm going to strip them again and put them back together later today and see.

    Lastly, what's the best way to get the thumb safety pin (the one that holds it in the off and on positions and acts on the slide catch on the other side) in place when you install the thumb safety without scratching the gun? I've been doing it stupidly but have gotten lucky and not scratched the gun yet, but I'd sure like to know a better way.
     
  20. RogersPrecision

    RogersPrecision Member

    Joined:
    Nov 22, 2003
    Messages:
    588
    Location:
    n az
    "I did fart around with the trigger/hammer/safety three prong spring thingy."

    :uhoh:

    :scrutiny:
     
  21. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Meaning I ben the spring arm, the one that contacts the thumb safety on the far right side when facing the back of the gun, in a little. Then back out a little. Maybe I should just buy a new spring. Maybe this isn't the best approach to gunsmithing :p
     
  22. Old Fuff

    Old Fuff Member

    Joined:
    Dec 24, 2002
    Messages:
    23,907
    Location:
    Arizona
    Last I knew, that leaf on the spring tensioned the grip safety, and had nothing too do with the safety lock (manual safety).

    Ya' think?? :scrutiny: :D
     
  23. carnaby

    carnaby Member

    Joined:
    Feb 25, 2004
    Messages:
    1,394
    Location:
    Bellingham, WA
    Sorry, I meant the grip safety.
     
  24. Highway Magician

    Highway Magician Member

    Joined:
    Jan 4, 2005
    Messages:
    6
    When you're in a deep hole, QUIT DIGGING. :uhoh:
     
  25. 1911Tuner

    1911Tuner Moderator Emeritus

    Joined:
    May 22, 2003
    Messages:
    18,549
    Location:
    Lexington,North Carolina...or thereabouts
    Safety

    A word on the safeties on the 1911 pistol, its clones, and its variants...

    I am NOT advocating the use of a gun that has a non-functioning safety device...so let that be understood from Jump Street.

    In its last prototype before final modification for the US Army...way back in 1910...the pistol was pretty much exactly what we now know as the Model of 1911 US Army. Later modifications produced the 1911A1...but for all practical purposes, the three models were functionally identical, save for one detail.

    In the final prototype, the Model of 1910, there was no manual/thumb safety.
    Browning presented it with only the grip safety. The US Cavalry asked for...and got...the manual, slide-locking, sear-blocking thumb safety that we all have come to know and love.

    If you use the gun as is, only loading it on the firing line and firing it until it's empty, or clearing the gun if it's not empty...you'll probably never have a real cause to even engage the safety, and the gun will be no more dangerous than if it was used in the same manner with a perfectly functioning manual safety.

    BUT...Should you or someone else accidentally shoot themselves or someone else with the gun in that condition...regardless of whether they engaged and trusted the safety...and regardless of whether a perfectly functioning safety would have prevented the shooting...YOU will be held accountable by way of gross negligence, if not criminal negligence.

    The choice is yours. My personal choice is to see that all safety features are in working order, regardless of what the gun is used for, and in what condition it's carried or transported. A new safety is cheap in comparison to what the cost could be should the worst scenario come to pass.
     
Thread Status:
Not open for further replies.
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice