Why do SAO handguns need manual safeties, but striker fired ones dont?

Discussion in 'Handguns: Autoloaders' started by MemeMagic, Feb 26, 2017.

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  1. MTMilitiaman

    MTMilitiaman Member

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    The point of discussing the load of the striker is because that partially determines both the length and weight of the trigger pull. You can play with spring weights, add a 3.5 power disconnector to your Glock, but you're never going to get it as short or as light as a tuned SAO trigger. The trigger on the SAO doesn't have to pull back the hammer 40% of the way and release it. The disconnector weight on your Glock is not your pull weight. The standard disconnector is like 5.5 lbs but the pull ends up being a pound or so more. So you can add a 3.5 lb disconnector to your Glock and play with some spring weights, but it is really hard to get it much below 4.5 pounds. Actually more common on defensively carried firearms are the NY trigger modifications which add to the pull weight but make it a little more smooth so it ends up being like a 10 pound DA revolver trigger. I keep mine pretty stock. All I've done to my 10mm is add a stainless guide rod with a 20 lb spring.

    Even with the lighter trigger pulls though, we still have to acknowledge that the Glock is designed to be carried without a safety. It has striker blocks and drop safeties. Yes it will fire if the trigger is pulled, but probably not otherwise. Glocks have been dragged behind moving vehicles, shot out of cannons, and dropped out of airplanes to demonstrate this. The 1911 is designed to be carried with the safety engaged. Yes it has a grip safety in addition, but it still isn't as safe without the safety engaged as say, a Springfield XD. Because again, the XD is designed to be carried without a safety whereas the 1911 may not be, esp if it is an originally configured Series-70. Carry what you are confident in the way it was meant to be carried, but don't disregard an entire class of pistols based solely on the presence of a safety or whether it's safe for unsafe people.

    A safety is not difficult to master. It doesn't add time or complexity to the draw stroke. People are getting too caught up in the safety. If the pistol has a safety it is probably best you use it. If a pistol doesn't have a safety, that's fine too. Practice with what you got and be safe. Safety is a frame of mind, not a mechanical device.
     
  2. pblanc

    pblanc Member

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    My point was that people seem to be expressing the idea that having the striker say only 2/3 pretensioned as in a Glock, but not enough to result in ignition, is safer than another striker-fired gun that has the striker essentially completely tensioned, even though the length and weight of the trigger pull is essentially the same.

    The Glock 17 is categorized as DAO and advertises a 5.5 lb stock trigger pull weight. The Springfield XDs are claimed to have 5.5-7.5 lb trigger pull weight, and are considered to be SAO. The Smith and Wesson M&P I understand to have the striker about 98% tensioned by the slide but call themselves DAO and have trigger pull weights on the order of 5.5-7.5 lbs. I have read that the striker on the SIG P320 is virtually completely tensioned by the slide action and advertised trigger pull weight is 5.5-7.5 lbs, yet it is classified DAO.

    It seems that the degree to which the striker is pretensioned does not have that great an influence on trigger function, at least insofar as trigger pull weight is concerned. It might have something to do with the length of the trigger pull, and Glocks do seem to have more take-up and therefore a longer total pull length. But even with the Glock, the pull length is much shorter than that of say my hammer-fired SIG P250 DAO or the DA pull of my Ruger GP100 double action revolver, both of which have trigger pull lengths of 3/4" or more, and of course, much heavier pull weights as well.

    The somewhat longer trigger pull of Glocks might perhaps provide some small element of safety against accidental discharges even though they have pull weights no more, and sometimes less than other striker-fired pistols classified as SAO, but I am not convinced of it.
     
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  3. bsms

    bsms Member

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    My Shield has about 1/8" of slack in the trigger, then another 1/4" of mushy travel. The pressure required for that 1/4" of mush is minimal - don't have a way to measure it. Nothing external to the gun warns me.

    My Pico has about 3/8" of travel. Subjectively, it requires about 3 times the pull. And the hammer moves back, so if I holster it with my thumb against the hammer, I MUST feel that something is happening.

    My Beretta 92 has at least 1/2" of trigger movement, maybe 4 times the weight of pull of the Shield. And, of course, the hammer moves. It is a smoother trigger in DA than the Pico, but closer to my revolvers in DA feel.

    I don't know and don't care how the trigger on my Shield is classified. Apart from being squishy mush, it is MUCH easier to move it to the point of firing, and doing so doesn't give me any other warning. The trigger moves too easy and without any other warning my hand can feel. It is perfectly safe when handled right, but it makes mistakes easier.

    There was a guy shot in Costco in Las Vegas a few years back. The cops gave a warning and a few seconds later opened fire. The suspect's gun was still in its holster. I've always suspected one of the cops with a drawn gun accidentally fired, and then the rest joined in. And of course, no one could say, "Oops, I didn't mean to start shooting!" - so it became 'I perceived a threat'. Cops can get away with that. Most of us could not and should not.

    I no longer carry my Shield. I'd rather go with a J-frame backed up by the Pico. Or the 92, if concealing it is an option. Or my 686+ with 7 rounds of 357. But the Shield sits at home, waiting to be traded in on another gun sometime in the future. If my Shield had a big safety on it, I'd consider carrying it. As is...no thanks.
     
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  4. X-Rap

    X-Rap Member

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    Unlike you I've long suspected some of the above shootings as well as non injury ND's to be attributed to DA/SA or SA only revolvers and pistols that were cocked and triggered unintentionally in either a careless or high stress situation.
    I doubt there is accurate data for either of our claims but I believe they are equally plausible.
     
  5. Walt Sherrill

    Walt Sherrill Member

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    On the FN Forum there was a discussion about a good-sized police department (San Diego?) using the new FNS-9 guns in which an officer had having an accidental(?) discharge. No witnesses. Only the officer in question claiming it happened with the gun in his holster and his hand not near the gun. The only witnesses weren't visual witnesses -- they just HEARD the sound of the pistol's round going off. After all sorts of inquiries I think they eventually blamed the gun. A gun which has a firing pin safety as part of the mechanism.

    So many claims and attributions are for events that are unwitnessed or in which co-workers circle the wagons to keep someone {typically someone well-liked and otherwise a good guy) from getting a disciplinary action, getting fired, etc.
     
  6. ATLDave

    ATLDave Member

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    That's why the ones that happen on video are so valuable (as information sources).
     
  7. bsms

    bsms Member

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    Disagree. The first shot is what started the shooting, and the first shot of a DA/SA auto takes significant effort - unlike the first shot of a striker gun. IIRC, the cop who shot first at the Costco shooting was carrying a Glock. Not sure how one unintentionally cocks a DA auto any more than someone unintentionally cocks a DA revolver.
     
  8. X-Rap

    X-Rap Member

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    It is entirely plausible to have the hammer drawn back on a DA or SA pistol or DA/SA Revolver without having intentionally fired a shot. The 1911 is only the flick of the safety, the K Frame S&W only has to have the hammer drawn back and the Berretta 92 can also have the hammer cocked without a shot fired to name a few.
     
  9. bsms

    bsms Member

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    It is entirely possible, but I can't imagine doing so without KNOWING you have done so. And if you have a habit of putting your thumb on top of the hammer, it is impossible to holster a cocked revolver or 92 unintentionally. That is quite different from a striker fired gun. I also cannot imagine cocking a revolver or going to single action on a 92 by accident, thus pointing a gun with a very light trigger pull accidentally. If I pull the hammer back while raising a revolver, it means I have already decided to fire. If I am SA with a 92, it means I have ALREADY fired...
     
  10. pblanc

    pblanc Member

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    Manual cocking the hammer of a traditional double action (DA/SA) hammer-fired pistol, or a double action revolver requires a very deliberate act. I very much doubt this could be done accidentally or unintentionally. I suppose it is within the realm of possibility that it could be done without conscious recollection, but it seems unlikely. People who properly train for self-defense with double action revolvers and DA/SA pistols shoot them in double action for the revolver and for the first shot of the pistol. Having trained that way, it seems unlikely that someone would unconsciously cock the hammer in a critical situation.
     
  11. X-Rap

    X-Rap Member

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    Where is that video of the lady cop putting a round into the pavement next to the perp on the ground. I think that might be a 92.
    People get shot and shoot themselves more frequently than we desire to admit.
    Yours is better, mine is better because we do it this way on the range means nothing if we don't carry that into our day to day lives but since we don't do daily gunfights we rely on what we believe to have ingrained in our heads but show me the first person who hasn't, while trying to hurry out the door, been looking for their keys only to find them in their hand or something similar.
    Yeah sure, we know exactly how we'll handle a gunfight. Then of course since they are much like a car wreck how can we say that just because we pulled it off the first time the next will be even close to the same.
     
  12. pblanc

    pblanc Member

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    I know the video you are talking about, which is pretty ancient, by the way (at least 15 yrs old) although that is hardly the point. It was a Las Vegas Metropolitan PD officer and you can find the video pretty easily. It was a Beretta 92 or an M9, but those who have watched the video in slow motion zoomed up have said the hammer was not cocked. Could well have been a 92D model (DAO) as well for all we know.

    You can read more about it on this old thread:

    http://www.thehighroad.org/index.php?threads/actual-nd-caught-on-tape.23056/
     
  13. HexHead

    HexHead Member

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    Many police departments now require a double action or striker fired pistol for their duty issue gun.
     
  14. SSN Vet

    SSN Vet Member

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    You, my friend, desperately need a trigger job on your you SA. It's all about the "tink"
     
  15. X-Rap

    X-Rap Member

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    Guess I don't get it, my claim is exactly what yours is if I'm correct. Perhaps I should say there is a world of difference?
    Is that clearer.
     
  16. roscoe

    roscoe Member

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    Edit . . .
     
    Last edited: Mar 10, 2017
  17. Homerboy

    Homerboy Member

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    Before Glock graced the world with its presence, the vast majority of semi auto pistols had a manual safety. And nobody had a problem with them. So 30 years of hearing "Glock Perfection" has indoctrinated a whole new generation of shooters. Shooters who see them in cop holsters and equate that with them being "the best", instead of cheap enough and reliable enough to get the job done.

    But safety-less striker fired guns are "less safe" than those with safeties or hammer fired weapons. Which is why we have the term "Glock Leg".

    Manual safeties slowing you down? Who here has to think to step on the brake before shifting into gear? Me neither. It's automatic. And 5-10 minutes a day drawing and disengaging the safety has made it totally intuitive to me.

    And as for the comparison between striker guns and revolvers, save it. Standard striker triggers are less than 6 pounds. Sure, you can install a heavier New York trigger. But we're gun guys on this forum. A small
    Minority of gun owners. Most will buy a gun, shoot a box or two
    Of ammo, and call themselves trained. They won't even know heavier triggers are available nor will they install them. Hell, a good holster will prevent a revolver cylinder from turning even if the trigger is pulled on a holstered revolver.

    99.999% of us will never fire a weapon under stress of bodily harm. Yet we all handle weapons dozens of times a week.
     
    Last edited: Mar 10, 2017
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  18. SSN Vet

    SSN Vet Member

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    I misread your post.... thought you said their wasn't much noticeable difference
     
  19. SSN Vet

    SSN Vet Member

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    I don't know if you thoroughly understand the firing mechanism of the 1911 or not, but learning to do a detail strip and then really studying the interactive STI 3D 1911 mechanism animation will get you there pretty quickly.

    When in condition 0, the 1911 hammer spring is applying full force to the hammer via the hammer strut linkage. The only thing preventing the hammer from releasing and impacting the firing pin is the sear nose to hammer hook engagement. This is typically ~0.025 sq. in. of surface area, and this can often be further reduced by applying a relief cut to the engagement surface of the sear nose.

    This is what gives the beautifully crisp and light trigger brake that 1911 peeps love. But this is also why you absolutely need a manual safety with a cartridge in the pipe.

    The grip safety will be depressed while drawing the weapon or while holding it in a ready position. If you have any accidental impact to the frame of the gun, the resulting impulse might trip the sear.

    While drawing a 1911 in condition 0, any incidental contact to the trigger could trip the sear.

    Holsters don't protect the grip safety from incidental contact, and it's conceivable that the grip safety could be depressed while the weapon is holstered, leaving it vulnerable to inadvertent discharge if it is bumped.

    100% safe to carry in condition 0? Most would say no.

    Glocks... I'm not intimately familiar with and probably shouldn't comment, other than to say that I believe the striker spring is only partially charged after cycling the slide, and then you have the flippy-doo in the trigger itself.

    100% safe to carry with a round in the pipe? That depends on who you talk to.
     
  20. danez71

    danez71 Member

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    Getting back more to what I believe the context of the OP question is.... framing this around factory triggers as opposed to aftermarket or custom triggers.

    A factory glock or equivalent have about 5.5-6 to maybe 6.5lb trigger. That's right about the same as factory 1911 type triggers... maybe even a little lighter.

    Factory glock triggers have just under 4/8th" travel where-as 1911s seem to be more like 1/8+"-ish travel.


    So we're talking about a 5/16" difference in travel with the longer travel having a little lighter trigger when comparing factory guns.

    Doesn't seem substantially different enough to provide much to prevent a ND/AD particularly when/if something gets snagged in the trigger guard such as when holstering.
     
  21. Fine Figure of a Man

    Fine Figure of a Man Member

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    I hope I'm wrong, It seems like there are folks on this forum that would favor a requirement for manual safeties on all handguns.
     
  22. SSN Vet

    SSN Vet Member

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    My Series 80 Commander was just under 5# right out of the box, as measured with a Lyman digital trigger gage. I personally would be disappointed, if I paid good money for a 1911 and it had a 6.5# trigger pull.

    I've had discussions where I inquired what method was used to test the pull weight, only to find that the numbers came out of thin air, without every actually gaging them. There are a lot of things that go into perceived pull weight that are not germane to the physics of the mechanisms. And it is physics that makes guns go boom.

    I, personally, would not be in favor a regulating that all guns have a manual safety. Glocks are safe enough for some, maybe even most. I personally don't care for them, but that has little to do with safety. (I have a LCP with a round in the pipe stapped to my ankle right now and am not at all concerned about it) But I find it scary that people will carry a Glock and not be aware of the #1 mechanism by which they experience an accidental discharge... re-holstering with your finger inside the trigger guard.
     
    Last edited: Mar 10, 2017
  23. ATLDave

    ATLDave Member

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    I don't think there should be any such law or regulation. I have zero interest in semi-autos without such devices, and do not believe the aversion to them by some is rational.

    However, as a believer in freedom and pluralism, I'm ok with the fact that others will make decisions that make little or no sense to me. Any marginal risk is largely on the owner/user of the gun, and is successfully managed in 99.9+% of cases.
     
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  24. danez71

    danez71 Member

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    I bet you're not wrong.... but to clear, I'm not one of them.

    The fact the millions with out a manual saftey are used every day with it a problem indicates, to me, it's not a issue that deserves much alarm.
     
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  25. danez71

    danez71 Member

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    Springfield lists on thier websites the ranges I was referring to on several models. Rock Island was even higher. Colt didn't list. I don't remember for sure.... but I think Kimber and Ruger either didn't list or were around the same numbers.


    How they get to those numbers, I haven't a clue.
     
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