1911 Colt "series" and safety features

[Rainbow Demon]

I have a few milspec .45 ACP cartridges in my collection, near as I can tell these are WW2 or early fifties manufacture.
These have the rolled cannelure that forms an internal shoulder to prevent bullets being pushed back into the case, and a domed primer cup.
I seriously doubt that these could ignite from any reasonable drop test procedure, and IIRC the Navy tested the 1911 with this sort of ammo and had no rounds that fired. That hammer down or cocked and locked.

Some ammo manufactured these days is not really suited to this sort of handgun, as the slamfires and blow ups of some Glocks and other .40 S&W pistols a few years back would seem to indicate. You can't cut corners without compromising safety.

A too sensitive primer is something that a manufacturer should deal with before the ammo put on the shelves.

 

[1911Tuner]

WW2

I have a few milspec .45 ACP cartridges in my collection, near as I can tell these are WW2 or early fifties manufacture.
These have the rolled cannelure that forms an internal shoulder to prevent bullets being pushed back into the case,

The cannelured case was done more for the Thompson and M3 sub machineguns than for the pistol. By WW2, the role of the 1911 pistol had changed. Issued to officers, tank and mortar crews and the like, it was no longer the primary arm for mounted cavalry, and would see little actual use on the battlefield. Of course, many infantry riflemen would scrounge for one in case of emergency, but they carried them concealed.

 

[polyphemus]

Just for the sake of clarity,the m1911 is a military weapon,not a swiss watch.
So when I read about those refinements to it,I bring out the '43 Rand and look
at it,then I feel much better.

 

[4thHorseman]

Series 70 meant that the pistol was equipped with a collet bushing and Accurizer(tm) barrel. All else was mechanically identical to the original design. Although Series 70 has come to mean "No Lawyer Parts" that isn't its true meaning.

Series 80 ushered in the passive firing pin blocking safety. Along with it came the quarter-cock shelf that only serves as a hammer stop. The original captive half-cock notch was and is a safety, and it was so described by Browning in the 1910 patents before the thumb safety...or "Manual Slide Locking" safety was added.

As a side-note, in the 30s, the Swartz system was tried and ultimately rejected...so a firing pin blocking device is an old concept.

The thumb safety was the final modification. Added at the request of the US Cavalry for hasty reholstering in order to free up both hands when the mounted trooper found himself trying to hang onto a frightened horse. Thus the mantra: "Cocked and Locked! The way that JMB intended!" is a myth.

And before the dire warnings of the dangers involved with manually lowering the hammer start...instructions for accomplishing that with one hand are likewise described in the 1910 patents...in the same paragraph that describes the half-cock as the "Safety Position." A modification to the grip safety tang was made in order to facilitate one-hand decocking, and also described in the patents.

The pistol is designed to be carried in any way that the owner/user chooses.

And, no. Assuming that the firing pin's length is to spec...and the firing pin channel is to spec...a blow to the hammer in full-down Condition 2 won't fire the gun. You can beat the hammer with a hammer until the spur is flat, and the gun won't fire.
__________________

1911 Tuner, just an excellent run done on the 1911. Thank you for your time and effort in that post. Very interesting indeed.

Also slamfire, thank you for the posting. I was told that the 1911 series 70 was as safe as the 1911 series 80 when dropped. What an eye opener the test results revealed. The test dispelled and old rumor for me. Thank you.

 

[1911Tuner]

Drop

Also slamfire, thank you for the posting. I was told that the 1911 series 70 was as safe as the 1911 series 80 when dropped.

99.9% of the time, it is. The drop tests are performed under strictly controlled conditions. The gun is arranged so as to drop perpendicularly onto a hard surface from various heights. If we assume a new firing pin spring that is to original spec...the height required to fire the pistol is about 6 feet. If the pistol yaws just a couple degrees and strikes the concrete pad at an angle...which randomly dropped pistols usually do...the height requirement increases.

In short, most drop tests are unrealistic because they're designed and intended to provide the best chance of getting a discharge. A more useful test would be to drop it under the conditions that most are dropped...during the draw or reholstering. If they did that, they'd have to work a lot harder and longer to get the BANG that they're so fascinated with.

 

[1911Tuner]

ehhhh

What the hey. I've got a little time on my hands that I might not have later...so I'll go ahead and explain it. As I'm wont to do, I'll include a little story.

First...In the beginning, 1911 barrels were the same diameter from the 3rd lug extension to the muzzle. Bushings were relatively loose in the frame and had fairly generous clearances with the barrel. This is important in that it allows the barrels to drop as soon as the link starts to tug on them. The introduction of the collet bushing and modified barrel was simply Colt's response to the growing demand for better accuracy than was provided with the ordnance-spec Government Model...and it worked very well for that. Had Colt included the caveat about backing up the slide before attempting to turn the bushing, most if not all the problems with broken fingers would have been avoided.

On to the story.

2-3 years ago, a casual acquaintance whom I'd helped with a couple of 1911 functional problems scored a LNIB Series 70 Government Model. He'd heard a little about the problems with the collet bushing, and wanted to avoid them as well as preserve the original parts for his pistol. He ordered an MGW semi drop-in bushing and installed it. The MGW bushing usually requires light fitting to the slide, and provides about .002 inch or less clearance with the barrel in most cases.

What he didn't realize is that the enlarged portion of the Accurizer(tm) barrel is about 3 times longer than what has become the industry standard.

The Series 70 barrel led to an epiphany. The manufacturers saw that they could obtain a closer fit with the barrel with the pistols in battery without sacrificing drop clearance. All they had to do was shorten the enlarged section, and they were good to go. Accuracy indeed improved.

When a solid bushing such as the MGW...which is a very good bushing by the way...is installed along with a Series 70 Accurizer(tm) barrel...the longer enlarged portion often doesn't allow the barrel to drop far enough for the upper lugs to get clear of the slide.

My friend fired his pistol about 500 times, and on field stripping...noticed that his barrel and slide lugs were getting torn up. He called me on a Saturday morning, and I told him to come on down. He never mentioned the new pistol, nor the decision to use the MGW bushing...only that he had a lug problem with a 1911 pistol.

When he showed up, I field-stripped it and spotted the problem immediately...explained why it had happened...and gave him the bad news. There was nothing I could do. The slide on a very nice old Series 70 was dead meat, and it all could have been avoided with a short, simple explanation had he taken the time to do a little research or just make a phone call...and it's not the only time I've heard of this happening.

Incidentally, I've seen the same damage done on Norinco pistols...which use the original barrel contour...when the owners hard-fit a bushing without understanding that drop clearance requirement.


To the rank and file, "Series 70" has come to mean "No extra parts." To those of us who understand the design and wrench on the pistols...Series 70 means something specific, and it's not related to the fire control group. Not knowing the difference can be costly...which leads me into these discussions and the sometimes resulting flame wars.

 

[polyphemus]

Food for thought,thank you for taking the time.

 

[1911Tuner]

re:

Well...I actually posted that on the wrong discussion, but I'm happy that somebody gained something from it.

Cut and paste...do your thing!

 

[Rainbow Demon]

The cannelured case was done more for the Thompson and M3 sub machineguns than for the pistol.

Entries on ammunition in the older manuals for the 1911 lead me to believe the cannelure was standard for the pistol ammo long before the Thompson was developed.
From the extremely high rates of fire of those handguns converted to selective fire it would appear that the slide of the average locked breech autoloading pistol if anything cycles more violently than that of a blowback SMG.

Regardless the incidents involving casehead blowouts,(mostly of pistols other than the 1911 but with similar tilting barrel locking mechanisms) due to bullets being pushed back into the case should make it clear that the cannelure is a big plus for ammunition intended for autoloading handguns. Manufacturers seem to have lost sight of some of the basics known to previous generations of ammunition manufacturers.
I also have some very old Remington commercial 9mm Luger ammo that has the case cannelure. I doubt it was manufactured with submachineguns in mind.

The description of .45 ACP ammunition from the original manual for the 1911 pistol.

AMMUNITION FOR AUTOMATIC PISTOL CALIBER .45, MODEL OF
1911— BALL CARTRIDGE.

(Plate VI.)

The components of the ball cartridge consist of cartridge case,
primer, powder, and bullet.

CARTRIDGE CASE.

The cartridge case is cylindrical and is made of brass. It is pro-
vided with a cannelure to prevent the bullet being forced down on
the powder.

PRIMER.

The primer consists of a cup which contains the primer composi-
tion, a paper disk, and an anvil which resists the blow of the firing
pin. The anvil is provided with two vents by which the flame is
communicated to the charge. Ignition is produced by crushing the
composition between the cup and anvil by a blow of the firing pin.

POWDER.



The powder is a smokeless powder. The charge varies with the
kind and lot, but it is generally about 5 grains.



20

BULLET.

The body of the bullet is a cylinder. The bullet has a core of
lead and tin composition inclosed in a jacket of gilding metal or
cupro-nickel. It weighs 230 ±2 grains.

Inches.

Length of bullet 0.662

Diameter of cylindrical part of bullet .45015

Total length of cartridge 1.261

To render the cartridge waterproof the inside of the neck of the
case and the outside of the primer are shellacked.

PACKING.

The cartridges are packed in pasteboard boxes containing 20
cartridges each. One hundred pasteboard boxes, or 2,000 car-
tridges are packed in one zinc case, hermetically sealed, with handle
for tearing open. The whole is inclosed in a wooden, box, the cover
of which is fastened with screw hooks and thumb nuts and sealed.

Pounds.

Weight of 100 cartridges 4. 6

Weight of 2,000 cartridges, packed 110

"War Department,

Office of the Chief of Ordnance,

Washington, February 14, OllJ^.
13092—2873.
Aprtl 1, 1912.

Revised, Febr.uary 14, 1914.
Form No. 1866.
Ed. June 13-17—20,000.

Printed a few years before the Thompson was invented and much longer before the Thompson was adopted by the U S Military.

Free download here
http://archive.org/details/descriptionofaut00unitrich

 

[1911Tuner]

re:

Entries on ammunition in the older manuals for the 1911 lead me to believe the cannelure was standard for the pistol ammo long before the Thompson was developed.

I probably should have qualified it by saying that during WW2, the main reason was for the sub guns. During WW1, the pistol was taking an active role in combat. By WW2, its role had changed. It was ssued to personnel who weren't normally issued rifles, and was fired in angle much less often...usually only during an emergency, and the incidence of having to clear and rechamber the top round several times was no longer an issue.