Recoil vs. Blowback

[John Y.]

What's the difference between a recoil operated pistol and a blowback operated pistol?

JY

 

[Khalnath]

Recoil operated firearms have some form of locking system to delay the opening of the chamber. Blowback operated firearms do not have a locking system, and only spring tension holds the chamber closed. Because the spring tension must be strong enough for the recoil of the cartridge used, there is a practical upper limit to how powerful a cartridge you can design a blowback gun for. IIRC, it's about 9mm Makarov. (Weaker than 9x19mm)

 

[nairbg]

hrmmmmmm!!

 

[Boomer686]

.....Because the spring tension must be strong enough for the recoil of the cartridge used, there is a practical upper limit to how powerful a cartridge you can design a blowback gun for. IIRC, it's about 9mm Makarov. (Weaker than 9x19mm)

I agree with your basic description in design diference... BUT:

Are you are saying you can't have a blowback design in a firearm bigger than 9mm Mak???

The HK MP5 is 9mm para, as are the Beretta Storms and SAF. Furthermore, you can get the Storm and SAF in .40SW. Beretta takes it one further again and produces a .45ACP Storm. All these and many more subguns are available with a blowback design in calibers more powerful than 9mm Mak!

Regards,

 

[TightGroup]

The assumption was mode for pistols.

I do not believe that there was a succesful 9mm blowback pistol manufactured, then again I think that there where a few commercially available units,

Let me go check before I shoot my ass off again

 

[EdGCNM]

I think it's actually a little more complicated than that. It is not just the spring that holds the action closed, but also the mass of the slide assembly. When the cartridge is fired, pressures are created by the rapidly expanding gases that push the bullet down the barrel and the slide mechanism to the rear. The action needs to remain closed until the bullet exits the barrel. The mass of the bullet is tiny compared to the mass of the slide mechanism, so even though the forces may be equal and opposite, the effect of the force on the bullet is dramatically greater than it is on the slide. It accelerates down and out of the barrel before the slide barely moves. The recoil spring adds to this basic mass differential.

 

[tiriaq]

Astra 600 is blowback 9mm Para. There are others, but the vast majority of higher power pistols are locked breech.