USGI Thumb Safety Design

[1911Tuner]

Well gang...The forum is kinda slow today, and I thought it might be a good time to discuss another part of the design that a few wonder about, but few really look at from the right perspective. I've always had a thing about studying a design to try and determine the intent of the designer...and the 1911 has been a never-ending lesson.

The thumb safety.

I had a guy ask me once why the good Mr. Browning designed it with such a small thumb pad...which makes it harder to hit in a hurry under stress.
Good question...and a very simple answer.

Keeping in mind that the good Mr. Browning...for all his insight and attention to detail..never envisioned that his pistol would ever be deployed
in a speed rig for fast-draw games...nor even that it would be fast-drawn at all, regardless of the rig or the need. Remember that it was to be carried in a full flap holster, and used whenever action was iminent...which would provide ample opportunity and time to have the thumb positioned solidly on the pad for a quick release.

There is another reason for the small pad...or more exactly...for the wide flat area directly behind it. Bear in mind that almost nothing that Browning did was incidental...and that the gun was designed and intended for complete disassembly without tools other than the gun's own parts.

The first step in a detail strip...right after the initial field strip...is the removal of the thumb safety. Once the safety is removed, the next thing to come out is the mainspring housing pin. Note that the thumb safety's
crosspin is the perfect size...or just enough undersized to easily push out the mainspring housing pin....but THAT pin is semi-locked in place by the mainspring plunger detent and the groove in the pin. It has to be knocked out, rather than simply pushed.

Enter the thumb safety pin. Look closely at the flat area behind the pad.
It allows a flat striking surface that is directly over the pin, which prevents
bending the pin, or causing the body of the thumb safety to be knocked out of square with the pin's axis...or damaging the thumb pad. The top of the slide strikes the flat surface and drives out the mainspring housing pin in handy fashion.

The early teardrop style thumb safeties were more positive, to be sure...and later, the speed safeties came along and made the gun even faster to deploy...but as with almost all "improvements"...gaining something
usually means losing something else.

My daily carry pistols have the teardrop-style safety...because it does offer a little faster and more positive grip on the pad. My pistols that are stashed away for that "Just in Case I gotta Grab One and Run" scenario,
(I have 3) are equipped with the old-style safety...cause ya just never know when ya might hafta take'er all the way down without tools.

Just a little trivial pursuit here...

Cheers all!

 

[sm]

Good Post Sir!

Yep - that is the way it was 'plained to me. The 1911 design is a tool unto itself.
Designed for the soldier riding horses, flap holsters...and such....

Word is, when a soldier back then removed saddle and gear....one could not depend for squat on Lt. passing out M16 firing pins to aid in disassembly .

 

[1911Tuner]

Step 2

Howdy SM...Spot on. No handy-dandy M-16 firin' pins back in them days.

Movin' on with the no-tool detail strip...

The safety crosspin pushes out the hammer pin..if it won't fall out under its
own weight. The strut pushes out the sear/disconnect pin. The sear spring
turns the mag catch lock, and then pushes in on the firing pin so that the firing pin stop can be removed, releasing the firing pin. The firing pin or the strut can be used to pry the extractor out...but I'd prefer to use the strut.
The firing pin was better deployed as a magazine takedown tool, and the front radius of the follower made a pretty decent scrape to get the gunk out of the spring tunnel and the feed ramp area. The side of the follower could be used to scrape the barrel throat clean. The sear spring could be used to scrape the frame rails clear of debris, and the checkering on the hammer did pretty good as a makeshift fingernail file.

The rim of a cartridge case fits the grip screw slots...or at least it used to,
and in case of a lost recoil spring plug, a fired case will work as an expedient plug until one can be found. The recoil spring plug itself HAD
a punched section near the end that would twist onto the open end of the recoil spring to keep the plug from takin' off into the wild blue if your thumb slipped off during a field-strip.

The plunger spring had a kink about halfway to keep the plunger assembly
from followin' suit and chasin' after the plug when the thumb safety came out.

The lanyard loop made a dandy bottle opener, and would even serve as a
decent skull pommel in a pinch. The rear sight was even better.

 

[joab]

I wish I had read this before I disassembled my newest 1911.
I knew it could be done but didn't know the particulars.
Wasn't hard to do with a leatherman but it would have been fun to do it the way it was supposed to be done

 

[1911Tuner]

The way we Were

Howdy joab,

Might not work exactly like that with a newer one...The thumb safeties don't have the flat area over the pin these days...and sometimes the round
part of the struts are too big to fit the holes that they were supposed to.
Most notably the strut design that Colt has been using since the Series 80
made their debut.

Now then! The reassembly...with the originally dimensioned "tools."

The hammer strut aligns the sear and disconnect with the holes. The hammer pin is a snap without a slave pin. The mainspring housing pin is wiggled through the holes in the frame, and up to the detent in the housing. The pistol is flipped over so that the cupped end of the pin is on something solid, asnd the grip frame whacked with the heel of the hand to drive it in. Additional. lighter bumps may be needed to seat the pin flush.

The thumb safety goes in after depressing the plunger. There are two parts that will accomplish that. The firing pin is one...but the hammer strut was used to get the firing pin back into the slide...so we can't use the firing pin. How do we depress the dangnabbed plunger???

Easy...Use the right ear of the barrel bushing. (The left ear won't do it.)
Fiddle with it for a minute or two...It'll come to ya.

Thumb safety reinstallation tip:

When depressing the plunger, instead of using the tip of a tool...which rolls off the end of the plunger...try standing the tool perpendicularly to the top of the frame and using the SIDE of the tool as you push the safety into place. of course, the tool must be small enough to allow the safety to move in far enough to capture the plunger and keep it from popping back out. The firing pin is good...but can't be used if it's already in the slide.
The bushing will work..but the best takedown/reassembly tool for the job is
an M-16/AR-15 firing pin. It just flat works. My understanding is that this
wasn't an accident. Eugene Stoner was a pretty sharp ol' bird his own bad self.

 

[Dave Sample]

WOW! I am sure glad we don't have to take them down like that anymore! I would have more sore fingers than I already do! The end of the sear spring works great for the grip screw bushings. Like Tuner, I am very fond of that WWI thumb safety. I have never had a problem with them and use them on some of my Toy Guns still. I am partial to an Ed Brown Thumb Safety, though. I like to take those big mud flaps and cut them in to where they are just right for me. Do you ever do that, Tuner?







A neat tool for 1911 tweaker's!



I think this is the one Tuner and I like!

 

[joab]

Might not work exactly like that with a newer one.

It's the Nork we were talking about elsewhere.
Did you get my PM

 

[Old Fuff]

Interestingly, during 1910 – less then a year before the model 1911 was adopted, the Army was still testing prototypes that in most respects were what would become the new service pistol, but still didn’t have a (manual) safety lock. That was the very last substantial adaptation Browning made, yet he incorporated all of the features Tuner described. Considering everything it was a marvelous job of engineering. Even during the early-middle 1920’s when the A-1 modifications were adopted, no changes in the safety lock were made – or even requested. Jeff Cooper, who originally popularized the concept of a longer, wider thumb pad eventually concluded that in most instances it wasn’t necessary. Yet today it is almost impossible to buy a pistol that isn’t so equipped, mil-spec models excluded.

 

[1911 TERRY]

I've been looking all over for one of those small thumb safeties. Do any of the parts manuf have them or do you have to modify an existing one?

 

[joab]

Try here Marstar .
They can export parts to US just not frames

 

[Jammer Six]

Is there any documentation that the fact the weapon can be taken down using it's own parts is more than a happy coincidence that was discovered by some enterprising corporal in a trench?

Is there a design requirement that can be verified?

Is the diameter of the slide stop pin more or less than the engineering would require?

Is there anything at all that either proves or disproves that these things were deliberate on Browning's part?

 

[tc300mag1]

Good thread like all the other 1911 clinics

 

[1911Tuner]

Documentation

Jammer demands to know:

Is there any documentation that the fact the weapon can be taken down using it's own parts is more than a happy coincidence that was discovered by some enterprising corporal in a trench?
Is there a design requirement that can be verified?
_____________________

Howdy Jammer,

I can't say for sure on that, but there are a couple of strong indications of it.

One...There's nothing new about the concept of miliraty arms being designed for simplicity and ease of disassembly in the field without special tools. Browning just seems to have taken it a step further...and No...It wasn't likely that it was discovered in the trenches by a "Tinkerin' Doughboy." It was probably known only among the unit armorers, and the complete disassembly by the rank and file was strictly verboten. That doesn't mean that none of them did it...It was just a no-no, and grounds for an Article 15 if caught.

Two...One part of the gun working as a tool to disassemble another part is a coincidence. Two parts doing so is lottery-winning odds. For all the parts mentioned being perfect for the task is strong indication of designer intent, whether documented or not. Remember that very little about any of Browning's designs was incidental. If it's there...you can pretty well be safe in betting that there's a very good reason.

These concepts are also rampant in other industries. A little-known example is the knock-down wooden crates that the Model T engines were packed in for shipment from Henry Ford's engine plant to his final assembly line, that when taken apart, became the floorboards for the cars.

So...study it and decide. Was it by design or by accident? The answer is pretty clear to me.

 

[Old Fuff]

Jammer:

Yes, there is documentation in the form of U.S. Military Field Manuals that show the pistol being disassembled in the manner Tuner has described.

The one I have in front of me at the moment is FM 23-35 that dates from the Korean War period. However I have seen the same thing in field manuals dating from as early as 1912.

You can often buy reprinted copies of these manuals at gun shows for very modest prices, and sometime you may even find an original one. If the price is right grab it! They are becoming fewer and fewer.

Unquestionably the pistol was designed to be taken apart without special tools. Also, since the information was available in commonly issued manuals I presume anyone issued a pistol was allowed to detail strip it if necessary for cleaning (as it sometimes was, but that's another story) unless specifically ordered not to by a superior officer. That might have happened, but I'm not aware of any specific cases.

 

[Dienekes]

My .45s from way back had the old small tab safety, and for me at least are better than any of the new improved ones. Last year I picked up a SA Mil-Spec with its bigger tab, and it just doesn't feel right. It may just get changed out if I find a decent GI safety and get it hard chromed to match the stainless finish. Not a big thing, but I am aware of it in handling the gun.

I found out about detail stripping the 1911 with only its own parts about forty years ago as a kid. The ability to do that any time and any place as needed puts it in a class of its own as a serious weapon. It's also why I prefer it over, say, the SIG 220/226/etc series. Get them full of mud, sand, and crud and the best you can hope for is to flush them out and hit them with an air hose if available.

The M1 with its accessories shows this same genius.

We could use more John Brownings and John Garands in our world.

 

[1911Tuner]

Field Manuals

Thanks Fuff. I had forgotten about those old Army Field manuals...I thought he was lookin' for documentation in a historical archive or somethin'...

Another point is that Browning wasn't the only designer to have his hands in the 1911...and he didn't just sit down and draw it one day. The gun evolved over a period of 7 or 8 years, beginning with the 1903 and finally
culminating with the Model of 1911A1.

Many of even the early features were the result of evlauations and requests for changes by the Ordnance Department, so it's entirely possible that some of the "toolbox" features were due to those requests.

Dienekes, your observation is IMHO, spot on. In its original form, the 1911 is in a class to itself, and not just because it's a single-action, single stack, 45 caliber autopistol.

Cheerios! (Honey Nut)

Tuner

 

[Jammer Six]

Actually, you guys, those FM's document the features, and I was looking for documentation that those features were intentional.

Once they had been discovered, FM's were written so everyone could play. That makes perfect sense to me, but it doesn't show that they were designed that way deliberately.

 

[1911Tuner]

Design Intent

>>Once they had been discovered, FM's were written so everyone could play. That makes perfect sense to me, but it doesn't show that they were designed that way deliberately.<<
____________________

Ummm...Okay! It was all a coincidence...Every bit of it.
You're probably spot on. Just for the sake of the discussion, let's rearrange things and see if we can figure it all out by applying the logic that it was all probably just a happy coincidence, and ol' John Moses just got lucky.

Lemme see...Browning sat down and whipped out a few drawings, and went to Colt to build a handful of prototypes to submit to the Army Ordnance Department for evaluation and further suggestions.

The Ordnance Board looked the gun over...made a few suggestions,
and Browning went back to the drawing board, went BACK to Colt, and eventually submmitted the guns for testing and further evaluation. The
pistol was adopted in 1911, and it went to war in the trenches a few years later.

During that time, a couple of enterprising grunts who were:
A...Willing to disassemble what could very possibly be needed at a moment's notice, and:
B...Willing to disobey a written directive, risking an Article 15 and possible Court Martial for disabling a weapon during a face-off with the enemy, and:
C...Immediately ran back to the rear to notify the unit armorer of their amazing discovery that Browning, Colt's engineers, and the Army Ordnance Department were all too stupid to see from the git-go.

Yep...Makes perfect sense to me.
_______________________________

Now then...back to the topic, guys. How' bout that M-16 firing pin. Show of hands from any who think that those stepped diameters just mighta been on purpose? Stoner was pretty sharp for both design and in noting the obvious.

The tip will push the mainspring cap pin out far enough to remove it...with a little help from a friend....(or a bench vise) The second step is a slave for aligning the sear and disconnect with the holes. The third step fits the
hammer pin hole, the grip safety hole, the mainspring hole, and the second step is the perfect size for depressing the plunger detent pin for reinstallation of the thumb safety.

An understanding of mass-production gives us understanding that one
extra machining step costs real money on a run of a half-million units, and
if not deemed necessary or useful, would be quickly eliminated. The firing pin could have been made with one diameter up to the tip...and simply tapered down to size much more inexpensively...or the course of a half-million parts.

So...Coincidence or intent? Study on it...and understand that within every
feature...There is a reason for its being done that way. If it can be done simpler (and cheaper) it would be.

Luck!

Tuner

 

[WhoKnowsWho]

Wow...

 

[Dave Sample]

It was made that way on purpose. It was designed to kill the enemy at close range (Up to 7 Yards) when all else failed. It was part of the Badge of Authority and issed to the officers mainly and was never designed to be a primary weapon and it still holds that place in the sun. It is carried by gunmen for unexpected, violent, criminal attack when they can't get to the primary weapon: ie: rifle/shotgun. It has never been, nor will it ever be, a primary weapon.

 

[1911Tuner]

Purposeful Intent

Dave said:

"It was made that way on purpose."
___________________________

Yep...And people been arguin' over that old "Yankee Fist" ever since.

I betcha ol John Moses is lookin' down on us and havin' hisself a good chuckle, goin:

"Dang! 93 years...and ya'll ain't got it figgered out YET?"

Cheers!

 

[BluesBear]

What a convienient accident in design.

Jammer-Six, so you think it is just a coincidence that the ORIGINAL US Army Manual for the 1911 pistol described disassembly using only the pistols parts?

So I guess the fact that the ORIGINAL instruction sheet packaged with the first commercial Colt Government Model pistols in 1912 that mentioned full dissassembly using only the pistol's parts was just an afterthought?

As a matter of fact, toolless takedown was described in the instruction sheets packed with each and every commercial Government and Commander model produced until at least the 1950s.

Here is a nice website that uses vintage photos to illustrate how a fully dismantle a 1911 with no tools.

Here's
another site that also shows and explains how it's done.

Why is it that almost every practical semi-automatic handgun design of the early 20th century (such as the Luger) had either its own takedown/combination/armorers tool or was designed for toolless takedown?

Where's the takedown tool for the 1911? Don't you think the Army would have specified one? At least on the regimental armorers level?

No, wait there was a 1911A1 takedown tool. But I believe they didn't come around until much later in the 1911s life.
It lookes similar to a hockey stick except made with a right angle. The "blade" was just that, a screwdriver blade that fit the grip screws and the "handle" was a round tipped punch that exactly fit the mainspring housing pin cup and could be used for a few others.

Toolless takedown of the 1911 was not an afterthought.
It was the the takedown tool that was the afterthought.

Have you never wondered why you see so many Luger takedown tools but you rarely see a 1911A1 takedown tool? Because it wasn't really needed.
Even today, with all of the gimmicks designed for the 1911 pattern, why is it that the only commonly encountered tool designed specifically for the 1911 pattern pistol is a bushing wrench? And that is totally superfluous if you're using a standard barrel bushing. (Ignoring of course any tools needed to remove those afterthought full length guide rods.)


Can you show me anything, on any gun designed by John Browning that is there by accident?

 

[Old Fuff]

A combination tool (screwdriver and punch) existed before the model 1911, as Browning used one to disassemble a pistol during the 1910 trials – if not before.

However these were not generally issued, except to individuals who were responsible for maintaining more then a single pistol. They did not normally come boxed with a pistol, they were purchased in far smaller numbers then the pistols themselves, and unlike the Luger and other European pistols USGI holsters never had a pocket or other provisions to carry such a tool. Last but not least, all of the Field (not Armorer) Manuals I’ve seen show the pistol being disassembled by a user without using special tools.

The earliest field manual I know of was dated sometime in 1912. It was obviously written well before that, and by the end of 1911 the Army had only received some 500 pistols. The photographs used in this manual were of a modified prototype “special model 1910,†not a production model 1911. It showed the pistol being disassembled without the combination tool.

 

[1911Tuner]

Let There Be Peace

Aight gang...Jammer's been roasted 'til he's well-done. Let him rest.

This was an InfoThread that I thought might be of interest for some of us who may not have known about that particular feature of the 1911...and a trip down memory lane for those of us who remember it. Sometimes the
old heads forget that what was once pretty common knowledge...isn't any more.

I think that Jammer...and probably a few others who just didn't
speak up...were havin' a few doubts about whether John Moses was
sharp enough to plan it that way and make it a reality. For the record...
Yes. He was. Was it such a miraculous breakthrough? Well...That was
one of the things that beat the pistol that Savage fielded for the trials,
and there were several who were pushing for the Savage. They thought the 1911 was too cumbersome and heavy, and tried to push their favored weapon ahead of the big Colt. Browning's design won the day because it beat the Savage in accuracy, durability/reliability...and its ability to be disassembled quickly and easily with a minimum of special tools and with a minimum of training...but the main reason that the Colt won out was because it met all these criteria and more...and it was delivered on time. Had the opposition's engineers had another 6 or 8 weeks to work out the bugs, we might well be collecting the Savage Model of 1911 U.S Army, and Browning's pistol would have been little more than a curio...a relic of the past.

Building a gun that used its own parts as takedown tools was a no-brainer for Browning, and careful study of the design reveals that it's actually pretty simple, and even crude when compared to something like a cuckoo clock or a V-8 engine. There are engineering marvels everywhere you look that make Browning's Brainchild look like an entry-level model airplane by comparison.

Also consider that the idea wasn't new or novel...and it didn't stop with the 1911. Look at the Armalite AR-15...later to become the M-16. By the time it was accepted for service, the rifle could be field-stripped with the tip of a bullet, and the lower receiver parts could be removed easily with nothing more than its own firing pin.

So...Let's be at peace with our brother Jammer. He's tryin' to learn about this thing just like all of us...me included. Seems like I learn somethin' "new" every time I pick one up. It was there all along...I just didn't look at it closely enough. John Moses Browning knew though.
Yessir he did. Betcha he's chucklin' this very minute and goin':

Cheers all!

Tuner