AD from M1911A1 Series 70 dropped on muzzle. - Page 2

Mike P. Wagner · May 7, 2001, 10:50 AM

My CZ-52 (circa 1953) has a little plunger that drops down into a groove in the firing pin, and locks the firing pin in place. The plunger is pushed up by a little "finger" on the sear when the trigger is pulled. I guess it's to prevent ADs from muzzle first drops. Interestingly enough, the most popular firing pin replacement kit disables that safety to give a lighter trigger pull.

I sort of wonder if the designer had empirical evidence of a "dropped on muzzle" problem, was just being clever, or somehow derived from the design that this was necessary/advisable.

Mike P. Wagner

John Lawson · May 7, 2001, 07:22 PM

Well, I have no idea how you'd set that one up without blocking the barrel, but I'm willing to bet that the primer would become the projectile with a bit more than a pfffft sound as it set back into the firing pin hole, propelled the firing pin forcibly backward and compressing the spring to maximum, imparting a horrendous blow to the firing pin stop.
Do you have documentation on this pffft result? I have never seen this kind of test even proposed. I do know that if you ignite the primer, oxidizers in the powder will rapidly burn the powder. If there is no place for the presures to go, there is no way for a slow bleedoff to happen and escalating, they will usually make their own pathway.
I'm refering to the SEE effect of light powder charges in a rifle, specifically when I say that this could result in detonation, not burning. Every scientist I know denies the effect, but I know of shooters who were maimed or killed due to the result.
"Recoil Operated" is a broad generic term that has to be further defined before it has any meaning. Luger and 1911 actions are nothing like similar in how they work...Compare a 16" Luger barrel with the 16" 1911 barrel. Now, the dissimilarities become more apparent. The Luger functions as it always did,as a locked breech, while the 1911 displays distinct signs of being a delayed blowback.
If you ignite the propellant from outside the case with an arc welding torch or a direct application of heat you get considerably more than a pffft. Been there; Done that.

Cheapo · May 8, 2001, 01:55 PM

JOHN!! JIM!!

You're missing a few of each others' points. The M1911 is recoil OPERATED, although there are signs of some residual pressure at the moment of unlocking. The Luger is also recoil OPERATED, but has such a long dwell time* as those parts move around, that no pressure strong enough to dislodge the case remains when the unlocking begins.

*by this, I mean the TOTAL time between primer ignition and the unlocking movement. This includes the time that the barrel is moving backwards but unlocking for either gun has not yet begun.

Both the Luger and M1911 can be said to be recoil unlocked. Both undoubtedly get some measureable (but operationally insignificant) assistance in rearward motion from the gas-jet effect of powder gases escaping the muzzle after the bullet exits. And both might begin to move the barrel backwards more than .01 inch before the bullet leaves the barrel.

Air resistance? Your own example shows how unreliable that is. As anyone who has gigged for frogs knows, motion/spin imparted to a flying/dropping object can make it strike "just right/wrong."

I'll believe the tests when you have 5 or more impacts directly muzzle-down. On concrete. No pads. Even then, I'd rather see a statistics database of X height, primer ignition Y percentage.

If you want your ammo to be 100% reliable, would you also accept a .2% chance of the gun going off with a muzzle-down drop from four feet? 1% from 6 feet? 5% from 8 feet, as in the stairwell you climb every day? How light is the light primer strike, and what's the measured risk of getting a discharge?

zot · May 8, 2001, 03:20 PM

I'm dumb for asking if thumb safety was on when 1911 was
droped and went off if the safety would be ruined or some gun damage, I bought a threaded barrel and the heavy fake supressor from Federal Arms Corp and the gun will not eject
if I fire the gun with the fake supressor hanging, the gun doesn't even open at all, and no pfft fart sound either?if
you lay the supressor on a rest the 1911 will rake and work as usual,should bought the aluminum fake thingy,they make some fair muzzle brakes too for the barrel.

teufelmann55 · May 13, 2001, 10:59 AM

Blowback-Found in automatic and semi-automatic guns where no mechanical locking system is used. When such a gun is fired, the weight of the hammer,slide and other mobile parts, as well as the recoil spring, combine to keep the action closed. Total weight of parts is greater than bullet weight,and projectile begins its travel before breech opens rearward due to residual pressure.(steindlers firearms dictionary).

Blowback Operation. Blowback operation (also called inertia action), in self loading weapons,uses spent case projection (cartridge case push-out) to force the bolt rearward, A primary characteristic of the weapons is the absence of any locking systems. Blowback operation may be divided into two types, which will be discussed in the paragraphs that follow.
(1) Straight Blowback. Straight Blowback weapons solely on the weight of the bolt plus spring tension to keep the breech closed until time of dangerous combustion chamber pressure passed and is most often found in low pressure ctg. weapons such as the M-3A1 submachinegun.
(2) Delayed Blowback. Delayed Blowback weapons have some sort of mechanical delay device by which the initial opening movement of the bolt is retarded slightly as the bolt overcomes the obstacle in its way. Examples of weapons using this type of operation are rifles and machineguns of foreign design since the US military insists on lock-breech high power weapons. (US Army definition from Ordnance manual verbatim)

Recoil Operation. This system uses the forward thrust (recoil) of the weapon to drive the barrel, bolt and other operating parts to the rear. The bolt is locked to the barrel and remains locked to the barrel until the bullet has left the muzzle and the gas pressure is reduced. After the bullet has left the muzzle, the bolt is unlocked from the barrel and continues to the rear. Various methods are used to unlock the bolt and actuate the other operating parts. The caliber .45 pistol has this type of operation.
(also verbatim from the same Army manaul as listed above)

I have seen example is .45s where with a broken extractor that the case sometimes stays in the chamber and sometimes does not. There are many factors involved in this: the rearward movement of the bbl.,case obturation and cooling of the case,tight/loose chamber,dirty vs clean chamber, & ammo pressure amongst other things can be the cause-not through blowback operation though.

I do not see where a M1911 meets any of the criteria for being a blowback weapon. It has a locked breech and does not seperate until the bullet has left the barrel.

This post is not meant to down any particular viewpoint but merely to illuminate operating systems.

clem · May 14, 2001, 08:41 PM

Hi all, today I received a reply from Colt, it is as follows:

"Upon confirming with our Engineering Department, I was able to verify that we did not produce the model that you have in question. We did manufacture an M1911A1 during W.W.II, and in the 1970's we had the Series 70, however both pistols were never combined. I have also confirmed that we did not have any recalls or safety concerns on either firearm.
If you have any further questions, please feel free to contact me and I will assist you in any way that I can.
Sincerely,
Maria Kilan
Customer Service"

My bust on the "model", I requested info on the M1911A1 Series 70. But, Colt appears to have not had any safety concerns about the pistol. So, the Series 80 was just to sell more pistols, I guess.

Clem

May 7, 2001, 10:50 AM	#26
Mike P. Wagner Senior Member Join Date: January 25, 2001 Posts: 451	My CZ-52 (circa 1953) has a little plunger that drops down into a groove in the firing pin, and locks the firing pin in place. The plunger is pushed up by a little "finger" on the sear when the trigger is pulled. I guess it's to prevent ADs from muzzle first drops. Interestingly enough, the most popular firing pin replacement kit disables that safety to give a lighter trigger pull. I sort of wonder if the designer had empirical evidence of a "dropped on muzzle" problem, was just being clever, or somehow derived from the design that this was necessary/advisable. Mike P. Wagner __________________ PCV Yemen 84-86 Past results are no guarantee of future performance.

May 7, 2001, 07:22 PM	#27
John Lawson Senior Member Join Date: August 28, 1999 Posts: 281	What's That You Say? Well, I have no idea how you'd set that one up without blocking the barrel, but I'm willing to bet that the primer would become the projectile with a bit more than a pfffft sound as it set back into the firing pin hole, propelled the firing pin forcibly backward and compressing the spring to maximum, imparting a horrendous blow to the firing pin stop. Do you have documentation on this pffft result? I have never seen this kind of test even proposed. I do know that if you ignite the primer, oxidizers in the powder will rapidly burn the powder. If there is no place for the presures to go, there is no way for a slow bleedoff to happen and escalating, they will usually make their own pathway. I'm refering to the SEE effect of light powder charges in a rifle, specifically when I say that this could result in detonation, not burning. Every scientist I know denies the effect, but I know of shooters who were maimed or killed due to the result. "Recoil Operated" is a broad generic term that has to be further defined before it has any meaning. Luger and 1911 actions are nothing like similar in how they work...Compare a 16" Luger barrel with the 16" 1911 barrel. Now, the dissimilarities become more apparent. The Luger functions as it always did,as a locked breech, while the 1911 displays distinct signs of being a delayed blowback. If you ignite the propellant from outside the case with an arc welding torch or a direct application of heat you get considerably more than a pffft. Been there; Done that.

May 13, 2001, 10:59 AM	#30
teufelmann55 Member Join Date: May 12, 2001 Posts: 92	Definition Of Blowback Blowback-Found in automatic and semi-automatic guns where no mechanical locking system is used. When such a gun is fired, the weight of the hammer,slide and other mobile parts, as well as the recoil spring, combine to keep the action closed. Total weight of parts is greater than bullet weight,and projectile begins its travel before breech opens rearward due to residual pressure.(steindlers firearms dictionary). Blowback Operation. Blowback operation (also called inertia action), in self loading weapons,uses spent case projection (cartridge case push-out) to force the bolt rearward, A primary characteristic of the weapons is the absence of any locking systems. Blowback operation may be divided into two types, which will be discussed in the paragraphs that follow. (1) Straight Blowback. Straight Blowback weapons solely on the weight of the bolt plus spring tension to keep the breech closed until time of dangerous combustion chamber pressure passed and is most often found in low pressure ctg. weapons such as the M-3A1 submachinegun. (2) Delayed Blowback. Delayed Blowback weapons have some sort of mechanical delay device by which the initial opening movement of the bolt is retarded slightly as the bolt overcomes the obstacle in its way. Examples of weapons using this type of operation are rifles and machineguns of foreign design since the US military insists on lock-breech high power weapons. (US Army definition from Ordnance manual verbatim) Recoil Operation. This system uses the forward thrust (recoil) of the weapon to drive the barrel, bolt and other operating parts to the rear. The bolt is locked to the barrel and remains locked to the barrel until the bullet has left the muzzle and the gas pressure is reduced. After the bullet has left the muzzle, the bolt is unlocked from the barrel and continues to the rear. Various methods are used to unlock the bolt and actuate the other operating parts. The caliber .45 pistol has this type of operation. (also verbatim from the same Army manaul as listed above) I have seen example is .45s where with a broken extractor that the case sometimes stays in the chamber and sometimes does not. There are many factors involved in this: the rearward movement of the bbl.,case obturation and cooling of the case,tight/loose chamber,dirty vs clean chamber, & ammo pressure amongst other things can be the cause-not through blowback operation though. I do not see where a M1911 meets any of the criteria for being a blowback weapon. It has a locked breech and does not seperate until the bullet has left the barrel. This post is not meant to down any particular viewpoint but merely to illuminate operating systems.

May 14, 2001, 08:41 PM	#31
clem Junior member Join Date: April 17, 2001 Location: Arizona Territory Posts: 847	A reply from Colt Hi all, today I received a reply from Colt, it is as follows: "Upon confirming with our Engineering Department, I was able to verify that we did not produce the model that you have in question. We did manufacture an M1911A1 during W.W.II, and in the 1970's we had the Series 70, however both pistols were never combined. I have also confirmed that we did not have any recalls or safety concerns on either firearm. If you have any further questions, please feel free to contact me and I will assist you in any way that I can. Sincerely, Maria Kilan Customer Service" My bust on the "model", I requested info on the M1911A1 Series 70. But, Colt appears to have not had any safety concerns about the pistol. So, the Series 80 was just to sell more pistols, I guess. Clem

May 8, 2001, 01:55 PM	#28
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	JOHN!! JIM!! You're missing a few of each others' points. The M1911 is recoil OPERATED, although there are signs of some residual pressure at the moment of unlocking. The Luger is also recoil OPERATED, but has such a long dwell time* as those parts move around, that no pressure strong enough to dislodge the case remains when the unlocking begins. *by this, I mean the TOTAL time between primer ignition and the unlocking movement. This includes the time that the barrel is moving backwards but unlocking for either gun has not yet begun. Both the Luger and M1911 can be said to be recoil unlocked. Both undoubtedly get some measureable (but operationally insignificant) assistance in rearward motion from the gas-jet effect of powder gases escaping the muzzle after the bullet exits. And both might begin to move the barrel backwards more than .01 inch before the bullet leaves the barrel. Air resistance? Your own example shows how unreliable that is. As anyone who has gigged for frogs knows, motion/spin imparted to a flying/dropping object can make it strike "just right/wrong." I'll believe the tests when you have 5 or more impacts directly muzzle-down. On concrete. No pads. Even then, I'd rather see a statistics database of X height, primer ignition Y percentage. If you want your ammo to be 100% reliable, would you also accept a .2% chance of the gun going off with a muzzle-down drop from four feet? 1% from 6 feet? 5% from 8 feet, as in the stairwell you climb every day? How light is the light primer strike, and what's the measured risk of getting a discharge?

May 8, 2001, 03:20 PM	#29
zot Senior Member Join Date: April 2, 1999 Location: U.S.A. Posts: 566	I'm dumb for asking if thumb safety was on when 1911 was droped and went off if the safety would be ruined or some gun damage, I bought a threaded barrel and the heavy fake supressor from Federal Arms Corp and the gun will not eject if I fire the gun with the fake supressor hanging, the gun doesn't even open at all, and no pfft fart sound either?if you lay the supressor on a rest the 1911 will rake and work as usual,should bought the aluminum fake thingy,they make some fair muzzle brakes too for the barrel.