I would like to find (preferably) a web site, or maybe a video, or (least favorite)a book that explains how each different autopistol action type works, how the parts interact, what does what to "delay recoil" or blowback, or whatever. I know a that a 1911 and say, an HK or Smith, have different parts but have some similarities. I bought one of the Wilson offerings, it did not have anything on the actual function of the gun it was for, the 5906. Ideas?
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Looking for info on autopistol functions....
- Thread starter Jhp147
- Start date
Just briefly, there are two basic types of auto pistols in general use. The first is the blowback (sometimes called "straight blowback") in which the empty cartridge is blown out of the chamber by gas pressure from the burning powder. This type of pistol is "locked" until pressure drops, only by the weight (mass) of the breechblock, usually a slide or bolt. The spring, unless heavy enough to add to the mass, serves only to slow and return the breechblock; it does not lock it. Blowback operation is feasible only with low power cartridges (.22, .32, .380) or very heavy breechblocks. With higher power rounds, the breechblock may open too soon and the high pressure gas will burst the cartridge case.
The other common type is the "recoil operated" pistol, used with higher power cartridges. In this system, the barrel and breechblock are locked together until the pressure drops enough to allow the breechblock to open. The barrel and breechblock move to the rear together, reacting to the recoil from the bullet moving forward, not from the pressure in the chamber. The breechblock is then unlocked from the barrel in some way (in the 1911, a link draws the barrel down out of the locked position) and the breechblock continues to the rear to extract the empty cartridge, eject it, and feed a new round from the magazine.
HTH
Nitpickers note: No, I did not forget about the various delayed or retarded blowbacks or gas operated pistols. I wanted to limit the reply to the common types. And for the fellow who once challenged me, yes, a Luger is a recoil operated pistol.
Jim
The other common type is the "recoil operated" pistol, used with higher power cartridges. In this system, the barrel and breechblock are locked together until the pressure drops enough to allow the breechblock to open. The barrel and breechblock move to the rear together, reacting to the recoil from the bullet moving forward, not from the pressure in the chamber. The breechblock is then unlocked from the barrel in some way (in the 1911, a link draws the barrel down out of the locked position) and the breechblock continues to the rear to extract the empty cartridge, eject it, and feed a new round from the magazine.
HTH
Nitpickers note: No, I did not forget about the various delayed or retarded blowbacks or gas operated pistols. I wanted to limit the reply to the common types. And for the fellow who once challenged me, yes, a Luger is a recoil operated pistol.
Jim
Thank you, Jim
This is a bit of what I wanted. I had an idea, based on comparison of the Walther to 1911 designs, how it works. I guess anything with lugs on the bbl. that lock into the slide (either in front of or at the chamber, maybe like the USP?) would be delayed. As far as "when the pressure drops enough to allow it to open," I am guessing that when the intial firing happens, the pressure of the bbl. being driven rearward is so great that the bbl. and areas inside the slide that engage the barrel lugs are locked together by the rearward forces, preventing the drop. Then, the pressure decreases (going out the front of the barrel) as the slide starts rearward. The decreased pressure reduces friction between lugs and slide surfaces they engage. The barrel can then be pulled away, in the downward motion provided by the barrel link. Okay, what does the job of the link in a delayed blowback gun that does not have one? One of the sloping surfaces below the chamber? And thanks. And now, a video of how triggers of various types are linked to and operate firing mechanisms....
This is a bit of what I wanted. I had an idea, based on comparison of the Walther to 1911 designs, how it works. I guess anything with lugs on the bbl. that lock into the slide (either in front of or at the chamber, maybe like the USP?) would be delayed. As far as "when the pressure drops enough to allow it to open," I am guessing that when the intial firing happens, the pressure of the bbl. being driven rearward is so great that the bbl. and areas inside the slide that engage the barrel lugs are locked together by the rearward forces, preventing the drop. Then, the pressure decreases (going out the front of the barrel) as the slide starts rearward. The decreased pressure reduces friction between lugs and slide surfaces they engage. The barrel can then be pulled away, in the downward motion provided by the barrel link. Okay, what does the job of the link in a delayed blowback gun that does not have one? One of the sloping surfaces below the chamber? And thanks. And now, a video of how triggers of various types are linked to and operate firing mechanisms....
Recoil operated arms function on momentum and timing. The mass of the bullet compared to the mass of the slide sets the initial timing. The slide moves in proportion velocity to the momentum imparted from firing. The velocity of the slide compared to that of the bullet is very close to mass of the bullet compared to the slide. These proportions are dictated by the law of momentum conservation.
So what does this mean? Recoil operated arms have some rearward travel while still locked. This travel allows the bullet to clear the barrel thereby allowing the chamber pressure to drop to safe levels. In most cases, the bullet has left the barrel long before the barrel has moved even a fraction of an inch.
Rest assured, if this mechanism relied on the friction to delay the opening, it would be short lived. The fact it is used on the M2 .50 cal BMG indicates it is fine for pistols. The only reason it isn't used on regular rifles is weight.
So what does this mean? Recoil operated arms have some rearward travel while still locked. This travel allows the bullet to clear the barrel thereby allowing the chamber pressure to drop to safe levels. In most cases, the bullet has left the barrel long before the barrel has moved even a fraction of an inch.
Rest assured, if this mechanism relied on the friction to delay the opening, it would be short lived. The fact it is used on the M2 .50 cal BMG indicates it is fine for pistols. The only reason it isn't used on regular rifles is weight.
Keith is correct; friction has nothing to do with it. When a recoil operated gun is fired, the barrel and breechblock (slide in most pistols) are locked together. They recoil together until something (like the link or a cam) disengages the barrel and breechblock. Then the breechblock continues rearward on its momentum (not on gas pressure, which by this point has dropped completely) to complete extraction, ejecting, and cocking. The rearward motion compresses the recoil spring, then it and the returned energy from the slide striking the frame (bounce) return the slide to battery, picking up a fresh round from the magazine and loading the chamber in the process.
Note that it is the recoil effect from the bullet's motion that begins the process. In a recoil operated action, if the bullet is prevented from moving, nothing happens.
Recoil operation is not limited to pistols. It has been used, as Keith says, in machineguns, in rifles (Remington Model 8 and 81, and the Johnson M1941) and in shotguns. The Browning Auto 5 and its copies use a long recoil operation in which the barrel and breechblock recoil together all the way back, then the barrel is freed to move forward under its spring (in the forearm). As the barrel reaches its forward point, it releases the breechblock, which moves forward under its own spring (in the butt) and reloads the barrel.
Jim
Note that it is the recoil effect from the bullet's motion that begins the process. In a recoil operated action, if the bullet is prevented from moving, nothing happens.
Recoil operation is not limited to pistols. It has been used, as Keith says, in machineguns, in rifles (Remington Model 8 and 81, and the Johnson M1941) and in shotguns. The Browning Auto 5 and its copies use a long recoil operation in which the barrel and breechblock recoil together all the way back, then the barrel is freed to move forward under its spring (in the forearm). As the barrel reaches its forward point, it releases the breechblock, which moves forward under its own spring (in the butt) and reloads the barrel.
Jim
See the operation section on this link to this 1911 site.
It is very detailed.
http://www.m1911.org/m1911dt.htm
It is very detailed.
http://www.m1911.org/m1911dt.htm
Hi, Cmc,
Not a bad site, but they are wrong about what makes the pistol operate. It is the recoil from the bullet motion that moves the barrel-slide unit to the rear, not the gas pushing on the case. In normal operation, the effect is the same, but if the bullet is prevented from moving, the slide will not move and the gun will not operate. The barrel and slide will remain locked together and the gas pressure in the case will simply leak out. That is why those pistols (1911, Luger, P.38, Mauser C96, etc.) are called "recoil operated" pistols.
Jim
Not a bad site, but they are wrong about what makes the pistol operate. It is the recoil from the bullet motion that moves the barrel-slide unit to the rear, not the gas pushing on the case. In normal operation, the effect is the same, but if the bullet is prevented from moving, the slide will not move and the gun will not operate. The barrel and slide will remain locked together and the gas pressure in the case will simply leak out. That is why those pistols (1911, Luger, P.38, Mauser C96, etc.) are called "recoil operated" pistols.
Jim
One minor quibble: if something prevents the bullet from moving in a recoil operated firearm, I wouldn't expect "nothing" to happen. If the bullet doesn't travel forward enough to unlock the breech, the result is almost certain to be a ruptured barrel. In this sense, blowback-operated or gas-retarded firearms may be safer than recoil-operated or gas-operated ones, since in the former there is a limit to the pressures that can be reached if the bullet gets stuck.
Also, it shouldn't be two confusing to mention the other two types of action: gas-retarded (also called retarded-blowback) and gas-operated.
In a gas-retarded firearm, there's a forward-facing cylinder underneath the barrel which is fed by gas taken from near the case mouth. Generally, the piston in this cylinder is deliberately not to have a very tight seal; when gas pressures are low, the gas can easily go through the gaps, but when pressures are higher the gas pushes much more strongly on the piston.
In a gas-operated firearm, the breech block is separate from the slide or bolt-carrier. For the rearward portion of the slide's travel, the breech block travels with it. The breech block reaches the forward end of its range before the slide; further forward travel by the slide does not move the breech block any further but instead causes one or more locking lugs on the breech block to engage lugs on the frame or barrel. The breech block is thus locked to the frame until something pushes the slide or bolt carrier rearward. This is typically accomplished by a small rearward-pointing cylinder near the muzzle end of the barrel.
Also, it shouldn't be two confusing to mention the other two types of action: gas-retarded (also called retarded-blowback) and gas-operated.
In a gas-retarded firearm, there's a forward-facing cylinder underneath the barrel which is fed by gas taken from near the case mouth. Generally, the piston in this cylinder is deliberately not to have a very tight seal; when gas pressures are low, the gas can easily go through the gaps, but when pressures are higher the gas pushes much more strongly on the piston.
In a gas-operated firearm, the breech block is separate from the slide or bolt-carrier. For the rearward portion of the slide's travel, the breech block travels with it. The breech block reaches the forward end of its range before the slide; further forward travel by the slide does not move the breech block any further but instead causes one or more locking lugs on the breech block to engage lugs on the frame or barrel. The breech block is thus locked to the frame until something pushes the slide or bolt carrier rearward. This is typically accomplished by a small rearward-pointing cylinder near the muzzle end of the barrel.