MadScientist
New member
Looked in the "firearms Terms" page but it wasn't there. Please describe the differences between a blow back and locked breech slide.
Thanks
Thanks
blow back vs. locked breech please
- Thread starter MadScientist
- Start date
Dfariswheel
New member
A blow back gun has no locking system. The only thing keeping the slide shut is the weight of the slide and the recoil spring.
It's usually limited to low power rounds, like the .22LR, .380, .25 etc. When firing, the weight of slide and recoil spring prevent the gun from opening until the pressure inside has dropped to safe levels.
Locked breech guns have some method of locking the slide and barrel together briefly. The usual methods are the Browning tilting barrel, rotating barrels, and gas locking. When firing, the slide and barel are held together for the amount of time it takes for the pressure to drop. Blow back can work for larger calibers, (most submachine guns are blowback) but the operating parts are too heavy to be practical in a handgun.
It's usually limited to low power rounds, like the .22LR, .380, .25 etc. When firing, the weight of slide and recoil spring prevent the gun from opening until the pressure inside has dropped to safe levels.
Locked breech guns have some method of locking the slide and barrel together briefly. The usual methods are the Browning tilting barrel, rotating barrels, and gas locking. When firing, the slide and barel are held together for the amount of time it takes for the pressure to drop. Blow back can work for larger calibers, (most submachine guns are blowback) but the operating parts are too heavy to be practical in a handgun.
Locked breech is also known as recoil operated where the barrel and slide recoil rearward together for a short distance until pressure drops when the bullet exits the bore. at this point the barrel pivots down based on browning type link/cam design. Allows higher chamber pressures and generally delivers less recoil than a comparable gun/caliber that is blowback.
Blowback is just that. Gun fires, slide blows back. Recoil and chamber pressure is controlled only by slide mass/inertia and recoil spring load. .380 is generally the upper limit of blowback unless you count retarded looking Lorcin type pistols in 9x19mm that use a huge alloy slide to gain enough inertial mass to contain the cartridge.
As stated, your wife probably doesn't want a blowback. where in C'ville are you? thats home to me.
Blowback is just that. Gun fires, slide blows back. Recoil and chamber pressure is controlled only by slide mass/inertia and recoil spring load. .380 is generally the upper limit of blowback unless you count retarded looking Lorcin type pistols in 9x19mm that use a huge alloy slide to gain enough inertial mass to contain the cartridge.
As stated, your wife probably doesn't want a blowback. where in C'ville are you? thats home to me.
There is another type of blowback used successfully on combat caliber pistols. It is called delayed blowback and functions just like normal blowback, but adds a device that delays the chamber opening. Most guns of this design work quite well and display absurd accuracy levels.
One type is gas delay, where gas is piped off the chamber to resist the slide movement. These include the HK P7, Steyr GB and Heritage Stealth. Works best with high pressure cartridges.
Mechanical delay is the other. First used on machine guns and assault rifles, it applies well to pistols of any caliber. The only two made are the HK P9S, which uses rollers and a camming surface for delay; and the Benelli B-76/80 series which uses lever arms to cam the slide.
These sophisticated systems work very well but the gun buying public is a bit old fashioned. Only two are still produced.
One type is gas delay, where gas is piped off the chamber to resist the slide movement. These include the HK P7, Steyr GB and Heritage Stealth. Works best with high pressure cartridges.
Mechanical delay is the other. First used on machine guns and assault rifles, it applies well to pistols of any caliber. The only two made are the HK P9S, which uses rollers and a camming surface for delay; and the Benelli B-76/80 series which uses lever arms to cam the slide.
These sophisticated systems work very well but the gun buying public is a bit old fashioned. Only two are still produced.
The reason for locked breech is relevant. In a blowback action, the breechblock begins to move when the pressure builds up. If the pressure is high, the breechblock will open too soon and allow the cartridge to back out of the chamber. The usual result is that the cartridge cannot contain the pressure and blows open, spraying gas and bits of brass through the action and perhaps harming the shooter.
The locked breech system insures that the pressure drops before the breech opens. In handguns, a recoil system is generally used; this means that no motion takes place until the bullet starts to move, and that the barrel and breechblock will remain locked together until the bullet has exited the barrel and the pressure has dropped to a safe level.
Jim
The locked breech system insures that the pressure drops before the breech opens. In handguns, a recoil system is generally used; this means that no motion takes place until the bullet starts to move, and that the barrel and breechblock will remain locked together until the bullet has exited the barrel and the pressure has dropped to a safe level.
Jim
As stated, your wife probably doesn't want a blowback
Why not? My Makarov, which is an EXCELLENT gun - uses the blowback design.
Don't get me wrong, I love my 1911 and believe that the locked breech design is every bit as good than the blowback design, but there ARE guns using the blowback design that she would/might want.
I think she needs to decide which caliber she wants. If it's higher than 9x18, then the breech design is it.
Why not? My Makarov, which is an EXCELLENT gun - uses the blowback design.
Don't get me wrong, I love my 1911 and believe that the locked breech design is every bit as good than the blowback design, but there ARE guns using the blowback design that she would/might want.
I think she needs to decide which caliber she wants. If it's higher than 9x18, then the breech design is it.
Why not? My Makarov, which is an EXCELLENT gun - uses the blowback design.
Maks can be nice but those people with less strength might have difficulty racking the slide of blowback guns in stronger calibers such as 9x18 since it is the recoil spring only holding the breach closed. Hence the spring needs to be pretty stout.
Maks can be nice but those people with less strength might have difficulty racking the slide of blowback guns in stronger calibers such as 9x18 since it is the recoil spring only holding the breach closed. Hence the spring needs to be pretty stout.
Modifiedbrowning
New member
It's a joke right? You just found a picture of that thing somewhere.
Navy Joe, I believe that the Lorcin is "mentally challenged" looking, not retarded looking.
Navy Joe, I believe that the Lorcin is "mentally challenged" looking, not retarded looking.
Is the Astra 400/600 bigger than an HK VP70? These modern 9mm handguns were also regular blowback. They worked fine, with the exception of a too-heavy trigger.
I think it would be safe to say that this is a topic where it would be foolish to make a sweeping generalization. There are plenty of ways of cycling bullets in and out of a chamber.
I think it would be safe to say that this is a topic where it would be foolish to make a sweeping generalization. There are plenty of ways of cycling bullets in and out of a chamber.
The Astra 400 and 600 had a heavy slide, a heavy spring, plus a hidden advantage. It is not quickly evident, but the hammer is placed so that it is at a heavy mechanical disadvantage when cocking. This acts to delay or retard the blowback action. It is easy to see the difference when retracting the slide with the hammer already cocked versus doing so with the hammer down.
Jim
Jim