M1911 Lock Time

[Bill99]

Can anyone tell me the timing specifications (range) for the lock time of teh M1911?

[1911Tuner]

To the best of my knowledge, it was never specified, and it would vary with the mainspring's condition. When the hammers were redesigned...from long, wide spur to short, wide spur to short, narrow spur...and then with the introduction of the Commander's rowel hammer...the lock time varied with each in hammer mass.

[irq23]

If you are looking to decrease lock time try using titanium components. I know plenty of competitive shooters who use 23# mainsprings, lightweight hammers, titanium hammer struts and titanium mainspring caps. The lightest steel hammer I am aware of is the Doug Koenig version made by EGW.

http://egw-guns.com/store/index.php?main_page=product_info&cPath=43&products_id=28&zenid=7602301b4bed8b8e4814154b63f13bc5

[1911Tuner]

Just a quick word on "Lock Time" if I may...

Reducing the lock time is a worthy pursuit in precision weapons that have been built with the nth degree of accuracy in mind. Long-distance riflemen benefit, as do Bullseye competitors who are chasing one ragged hole at 50 yards with a pistol. With pistols especially...reducing the hammer mass also disturbs the alignment of the gun less on the hammer's strike. It doesn't mean a lot...but every little bit helps.

The action competitors also benefit...a little...by shaving a couple hundredths of a second off their split times...though whatever practical purpose that serves remains a mystery unless the object is to demonstrate how fast they can fire the gun. Since the action matchs are supposedly designed to replicate real gunfights...I fail to see how an opponent could be stopped any faster...or killed any deader...if he's hit twice with .10 second between impacts, and .09 second...or any other tiny fractional amount.

I suppose that it means something to them...

[Bill99]

First, thank you gentlemen for your responses. I am an engineer and I am interested in the statistics relating to the time from sear release until propellant ignition. I would like to correlate the lock time with gunner's wobble to get a relationship with expected group size knowing that the gun is always in some random motion. I would also like to know relative comparisons for weapons like the Berretta 92 and the M16 rifle. The data probably exists somewhere, but finding it has been a challenge. I am thinking that a decent numbers are around 0.020 to 0.040 second, but I may be "off target" with this guess.

I would also like to know any information relating firing pin velocity to primer ignition time and burn time. This is a hobby, not work.

Any insights that could help me out would be appreciated.

[1911Tuner]

I would like to correlate the lock time with gunner's wobble to get a relationship with expected group size knowing that the gun is always in some random motion.

Hi Bill.

To many variables and unknowns to accurately predict it, other than hypothetically or theoretically. The shooter's grip, and grip consistency from shot to shot...and his natural wobble area are probably the two main ones. Recoil spring tension in preload and the rate of the spring as the slide starts to move...Trigger overtravel after the shot...Primer brisance and powder burn rate...things like that all have an effect on how much the gun moves between the instant that the hammer breaks and the bullet's exit.

[John]

I knew an old man once (Tuner, compared to him, you are still a young man), he was the president of a shooting club here. I once saw him firing a small tiny Walther .22 LR pistol (I do not remember how they called them TPH I think or something similar). I could see his hand holding the pistol wobble all around (and he was firing one-handed), that I would bet that he won't even hit the target board. Guess what, from the 5 shots he fired, all five were in the bullseye, 3 were 9s and 2 were clean 10s. Oh yes, and that was at 25 meters.

I felt very bad after this demonstration. Boohaaaaaaa, I can't do that even with a Walther GSP, a pure-breed competition pistol and he did it with a pocket gun!!!!

[1911Tuner]

John...Yep. Some folks learn to compensate for a large wobble area, and some can do it with surprising consistency. The trick is to train yourself to freeze your trigger finger as the gun moves...a little more pull and freeze...repeat if necessary...until just the right instant that the sights are coming into alignment with the bull...and bump the shot off with a staged trigger pull of about 2 ounces.

[Lazarus]

Bill99,

This subject has always been of interest to me. I'm not particularly interested in tweaking my lock times, but rather in the technical aspects of calculating hammer movement and accelleration. I know enough to realize that things get complicated very quickly; however if you are on a pursuit, it would be very interesting to hear about your methods and results.

A related topic is the calculation of hammer force delivered to the firing pin as the hammer mass is varied (hammer spring remains constant). Because of the large number of hammer designs, it seems very difficult to determine the effective rotational mass other than by empirical means.

In any case, please share any calculations and/or thoughts on the technical aspects of same.

Thanks!
Lazarus

[twins owner]

my daddy told me once....boy if it ain't broke ...don't fix it.

[Bill99]

Lazarus
After a day surfing I managed to come up with only one lock time number, .003 second, and it was for a Remington 700 rifle. They were discussing the electrically primed advantage. The 700 has a straight line system with no energy transfer so I would expect it to be fast. From my memory I recall seeing the M16 as about .008 with options down to .001 second. I question that last number. That is pretty fast for a mechanical system. I still think my guess of around 20 to 30 milliseconds for the M1911 is reasonable.
There are a lot of add-ons out there claiming to reduce this, but no numbers. Typically they go for a Titanium firing pin which is lighter and a lighter hammer. The only problem with this approach is that you need to drive that light pin faster in order to maintain the same energy crushing the primer. That means a stronger hammer spring and consequently higher trigger force, unless you mess with sear engagement. I am not sure one would gain anything regarding accuracy.
My origninal thought was to use a Gausian distribution of wobble over a circular area for simplicity, and look at the change in distribution one would get allowing different lock times. I am not sure I would show much, but when introducing a tip-off force introduced at sear release, I am guessing that a significant increase would be exposed.
I am open to people throwing rocks at this. Bill99

[Lazarus]

The only problem with this approach is that you need to drive that light pin faster in order to maintain the same energy crushing the primer. That means a stronger hammer spring and consequently higher trigger force, unless you mess with sear engagement. I am not sure one would gain anything regarding accuracy.


Thanks for your post, Bill. I also assumed the above, that a lighter hammer or lighter firing pin must receive a harder blow to do the same work as a heavier part. However, Hawk sent me a very convincing argument that changing the mass of the hammer, striker, or f.p. does not change the amount of work done on the primer (provided that the mainspring remains constant). This concept makes sense to me, but I wasn't a star pupil in physics.

The concern about reliable ignition caused by lighter components would then be irrelevant to your original inquiry of calculating actual lock times. One question relating to millisecond intervals is whether a human is capable of discerning such small intervals? If anyone in the forum shoots a rifle with electric ignition, perhaps he could post his observations and comparisions?

I have always appreciated a mechanical system when it comes to firearms, because the components of trigger squeeze and sight alignment originate with the mechanical movement of muscles. On the other hand, muscles are fired electrically by the nerves, so who is to say what is mechanical and what is not?

Lazarus

[1911Tuner]

ing the mass of the hammer, striker, or f.p. does not change the amount of work done on the primer (provided that the mainspring remains constant).


Well...I dunno if that holds completely true. As long as the momentum remains constant...yes. A 100-grain bullet can offer the same momentum on impact as a 200-grain bullet as long as the lighter bullet is moving fast enough. It's Mass X Velocity that we concern ourselves with, and sometimes the reduction in mass and the natural increase in velocity just doesn't balance out.

A perfect case in point would be Smith & Wesson's J-frame revolvers. It was very often a hitch in the gitalong when folks ground the hammer spurs away to make the little wheelguns more pocket carry accessible...only to discover that they misfired intermittently. The reason is that there's just not enough hammer mass. The sectional density part of the equation is, I'm sure, also a factor...but the main issue seems to be the hammer's mass. The practice and the ensuing problems were so prevalent in the 80s that I used to try to keep 2 or 3 of the hammers on hand in the shop...and it seemed that I was never able to hold on to'em for long. J-Frames were popular then, and the "humpback" Bodyguards were scarce...so they turned to bobbing the hammers on the Model 36's and 37s.

[niemi24s]

Years ago the American Rifleman had an article reporting the changes in a 1911 hammer's fall time. I can't seem to find my copy now, but will post some info - if I can locate it - and if you think it might be useful.

[jwenum]

I always thought that a lighter firing pin would accelerate faster(assuming everything else was the same);not hitting harder,just faster,to negate somewhat the 'wobble' factor in waiting for the firearm to actually go off..

[niemi24s]

Found the article referred to earlier. "A Faster Lock For The M1911" by Alton S. Dinan, Jr., is in the July 1970 issue of The American Riflemen.

He tests 3 hammers for their fall times: wide spur, standard & speed; fall times were 0.0057, 0.0047 & 0.0037 sec, respectively; hammer weights were 287.9, 261.1 & 201.9gns, respectively. The firing pin was not part of his test.

Regards

[1911Tuner]

Two thousandths of a second spread between the fastest and the slowest. That's an incredibly short time.

[niemi24s]

Probably even quicker than two shakes of a lamb's tail!

[Edited to add] The article makes no mention of mainspring rating used in the test gun, or the use of any lightweight cap or strut.

[Bill99]

Thanks for the inputs guys. I appreciate finally seeing real data. It looks like my 20 to 40 millisecond guess was off target.
As to the energy issue, form my mechanics dynamics back in my college days, in theory if you ignore friction, the energy imparted by the spring only considers two states. The initial force and length, and the final force and length. They should be identical regardless of hammer weight, so the energy imparted to the lighter hammer is a grater angular velocity giving the identical energy of the heaver hammer at the lower spaed. What I really have no idea of without taking measurements or looking up a ton of materials data, is how much of that energy translates to the firing pin at impact. I also do not know how the lighter pin would withstand repeatiitive hammer impacts without work hardening or eroding the impact area. I also know that the only real way of evaluating it is testing, and testing the primer's response when hit. To do that one would need a high speed camera and a cutaway case/barrel. I suppose individuals have done that, and it rests in some company's "trade secret" file. When we test the stuff we make where I work we always test at cold, room temperature and hot, and a design is not complete until it is well characterized and understood.

It is fun playing around, even if I don't have the tools to do the job right. I do find I can get great insight from guys like you all. It is a pleasure to read your responses.

Thanks, Bill 99

[flintsghost]

The lock time will change with the weight of the hammer and moving parts including mainspring, mainspring cap, hammer strut, firing pin and firing pin spring. The mainspring weights are 20 and 22 respectively for Govt and Commander. Using Titanium strut, mainspring cap, firing pin and hammer will make a tremendous difference that the shooter can actually feel. If one stays with the stock firing pin spring instead of the HD one such as Wolff supplies with his recoil springs then lock time is decreased dramatically. However, if one stays with the HD firing pin spring it will retard lock time somewhat. The trade off is that with all the lightened components and the heavier recoil spring that most competitors prefer, the primer of rounds fed into the chamber will normally show a slight but noticable mark where the firing pin moved forward during the loading cycle and marked it. For competition that can be considered OK. For daily use, I don't think personally that it's a good idea. The other trade off with titanium is that it tends to be brittle and gets weaker when subjected to constant battering. Consequently hammers crack and break during use and firing pins tend to break during use. Many competitors who use these types of parts try to replace them proactively prior to breakage after a certain number of rounds. Usually less than 2000. Considering their expense when new, titanium would have to yield a tremendous advantage to be worth the cost and problems. I have titanium speedlocked one custom competition pistol I built years ago as a demo, when I was in business. It hasn't had a problem yet but then I don't use it much. Hope that helps.

[John]

Using Titanium strut, mainspring cap, firing pin and hammer will make a tremendous difference that the shooter can actually feel.

Well, I'll tell you. I changed all those with titanium parts, some years ago (I paid something like 400$ for them, that's why I remember the incident), and I give you my word, I didn't feel any difference! The only difference was that my wallet was significantly lighter. Of course, I am not a world-class shooter, so maybe that was the reason.

[flintsghost]

It does all depend upon your experience and your feel. Some may not notice the difference and some who have considerable experience do. Everyone who has ever tried my demo gun and then picked up one that I have with all steel parts and the same lb trigger pull notices it instantly. I actually discourage people from doing it simply because of cost and expected longevity of the parts. However, cost of the parts I used to use which Mccormick no longer makes wasn't even close to $400. I believe when the hammer, strut, mainspring cap, and firing pin were added up it might almost come to $100 retail. At the time I was building 1911's exclusively on Colts and probably built over 10,000 when I was in business as an avocation. I doubt I did more than 20 with titanium lock work but I do still have the one which was my own demo gun.

[1911Tuner]

The mainspring weights are 20 and 22 respectively for Govt and Commander.

Standard mainspring rating is 23 pounds for both.

[Bill99]

Thanks Flintsgost,

I have always felt that it would be hard to replace properly heat treated carbon steel parts in a gun. The only advantages I see is shaving a couple milliseconds off the lock time, and the lighter firing pin would require a greater drop hight on the muzzle before the firing pin would have enough energy to set off the primer. I hardly think either is worth the price, especially when you can achieve some improvement by mechanically million off some material from the steel hammer (not that 99% of us could tell the difference).

Thanks for confirming my suspicions that the titanium parts don't last like steel parts. Bill99

[John]

Well, Chip's hammer was 100$ alone, when I got all his titanium parts.

[berkbw]

Well, Chip's hammer was 100$ alone, when I got all his titanium parts.

Yeah, John - Unobtanium is really pricey. And, I too, don't think that it has enough benefit to show up in scoring. If a guy shoots 1st place with that stuff, he would also do it without that stuff. When one is on the bleeding edge, everything which is theoretically advantageous is "needed" and used - and if one does enough of these "improvements", they just may add up - some.

Titanium HAS advantages over steels - but they are limited in their areas. Lock time has a theoretical meaning and value. Not likely for some hand held semi-auto shooter in these forums.

Lock time! phtooey! The only thing hammer mass will affect in a bad manner is how much a weak wrist fails to hold the gun @ POA when it's falling.

Smiles at'cha, Boss-

b-

[John]

I think I've mentioned it elsewhere (or was it in a PM? My memory chips are not what they used to be some years ago, I guess I need new ones, but Lena doesn't approve the expenses of a brain transplant). If you can place all your shots in a rough cloverleaf shape, with all holes touching each other, then you may benefit from the reduction of lock time and make that cloverleaf maybe 1/4" or 1/2" smaller. If your shots cover the whole black area of the target (even worst if not all of them are on target) don't worry about Unobtanium parts. You won't see the difference.

How do I know? It's a well established fact, that I am a lousy shot. What with two packs of Marlboro per day and several coffees (not American filter coffee). So my evaluation may not be worth much, after all I haven't build 10,000 guns (as an avocation of course) but my ex-wife of that time was in the Greek National Team. She could shoot all day long with her Walther GSP, putting 5/5 in the 10 and 9 ring. She may had a couple of shots in the 8 ring during the whole day of shooting (more than 200 rounds usually), if she was really tired but I wouldn't count on that if she had her beauty sleep the previous night. Well, she shot the Colt before and after the Unobtanium parts were installed and she pronounced it "the same". Oh and she never shot at distances smaller than 25 meters, in case you wonder, her discipline was 30+30, which is fired at that distance.

[1911Tuner]

after all I haven't build 10,000 guns (as an avocation of course)

Ten thousand??

Lemme go back and look........

...........................

Dang! Since avocation suggests that ya didn't quit your day job...and figgerin' on a 40-hour week in that pursuit...when did ya sleep, man?

[John]

It wasn't me partner, it was someone else who said he build 10,000 pistols as avocation.

Now if we figure that he has been doing that for 25 years, that's 400 pistols per year, or 1.09 pistols per day, day in day out, no vacation, no holidays, no nothing.

Yeap, that's an avocation all right!

[1911Tuner]

It wasn't me partner,

I done seen dat...
that's 400 pistols per year, or 1.09 pistols per day, day in day out, no vacation, no holidays, no nothing.

Yeap, that's an avocation all right!

No sir! That there's an obsession.

[Lazarus]

Thanks for posting those lock times, Niemi. I didn't think we were down to a few milliseconds on any firearm unless electrically fired. I have also heard of the problems of increased misfires in the S&W guns that had lightened hammers. So, if the basic physics is correct that hammer weight is NOT a factor, then we must be seeing the results of friction (static and dynamic) on the system. Apparently, friction has a much larger influence than you would expect, even though all the components are smooth and well-oiled.

So now, Bill, we need to correlate typical lock times for the 1911 (35-45 milliseconds) to charts of muscular wobbling activity over time.

Lazarus

[niemi24s]

Thanks for posting those lock times . . .

You're welcome.

Remember that these times were only from when the hammer began to fall to when the hammer's fall was stopped by the FP/FPS. No other 1911 parts' action/reaction time (like the FP) was measured.

Also remember that "...clocks do not measure some pre-existing thing called "time", ...time is simply a convenient way to abstract the common behavior of all those objects we call "clocks" ". [N.D. Mermin, Spooky Actions At A Distance: Mysteries Of The Quantum Theory, GBWW, Chicago]

Now is that some dee-e-e-p stuff, or what?? :D :D :D

Cheers

[1911Tuner]

So now, Bill, we need to correlate typical lock times for the 1911 (35-45 milliseconds) to charts of muscular wobbling activity over time.

If we factor in the elapsed time for the firing pin to strike, and the primer to fire...and the powder charge to reach peak pressure...and the bullet to exit the muzzle...we might have 75 milliseconds or so.

How far can you wobble in 75 milliseconds if you're trying to hold still? We're probably talkin' a tenth of an inch on the target at 25 yards.

[berkbw]

Also remember that "...clocks do not measure some pre-existing thing called "time", ...time is simply a convenient way to abstract the common behavior of all those objects we call "clocks" ". [N.D. Mermin, Spooky Actions At A Distance: Mysteries Of The Quantum Theory, GBWW, Chicago]


Time for you to go to sleep now. :)

[niemi24s]

Yawn. Snoz-z-z-z-z-z-z-z-z- ;)

[toolman]

How far can you wobble in 75 milliseconds if you're trying to hold still?
Some of us wobble a whole lot more than others! I'd hate to find out how far I can wobble in 75 milliseconds. :o

[niemi24s]

I'd hate to find out how far I can wobble in 75 milliseconds.
Not sure how you'd even measure how far anybody could wobble off target, but(FWIW) 75ms is how long it takes an object to fall (from rest, or not moving) only about 1.1 inch.

[Lazarus]

Ok, Bill and Hawk,

Here is a physics question. Consider the importance of Center of Rotational mass. Let's assume for a moment that the stock S&W hammer (as mentioned above) was designed so that the hammer pin hole was actually located at the CRM. There you have one type of rotational system. After removing the hammer spur, the CRM would then be someplace else on the hammer, (not at the original pin hole). With the modified hammer, you are now accellerating he remaining mass about a randomly chosen point.

If the foregoing is significant, then we cannot say that any hammer mass, when accellerated by a constant spring force, will do the same work on the primer. The CRM has changed, but the actual rotational point remains the same. The S&W experiment might be an example of this property.
Maybe?

-Lazarus

[John]

Some of us wobble a whole lot more than others!

Ah, did you had to bring this up?????? :(

[niemi24s]

I got a crisp new US$5 bill that says I can wobble more in 75ms than anybody out there! :D

[John]

Want to bet??

:lm:

[toolman]

If you can figger out how to measure it I'll take you on! :D