Please help me understand blowback and recoil

[cadence2arms]

Is my Bersa thunder .380 a blowback? Is my xdm 9 a recoil? I sort of know the difference on how they work but by looking at it how could you tell? Pics of any guns in either category would be much appreciated. Same thing for rifles if it applies.

[Edg]

I thought they were both blowback, not much difference in the way they operate aside from the location of the spring.

[ffoltz]

Your XD is recoil operated. When you push the slide to the rear, you will note the barrel drops down. This is the barrel unlocking.
With your Bersa the slide will just move back with no extra movement.To keep this barrel in place during firing you use the weight of the slide plus a strong recoil spring.
Does that help?
fred

[cadence2arms]

Your XD is recoil operated. When you push the slide to the rear, you will note the barrel drops down. This is the barrel unlocking.
With your Bersa the slide will just move back with no extra movement.To keep this barrel in place during firing you use the weight of the slide plus a strong recoil spring.
Does that help?
fred

It might, I have to go grab my gun and see what you mean by dropping down.

[cadence2arms]

Ok I looked at them and understand the difference. Thanks.

Now does the recoil type only come in smaller calibers because in a bigger caliber the recoil would be too much to handle?

[ffoltz]

You have them switched. Recoil operated comes in many more calibers. Thats the one with a locked barrel.
fred

[cadence2arms]

You have them switched. Recoil operated comes in many more calibers. Thats the one with a locked barrel.
fred

Ok so do they make a .45 blowback or would it hurt too bad to shoot?

[zackattack784]

Ok so do they make a .45 blowback or would it hurt too bad to shoot?

I believe all Hi-Point handguns are blowback operated. I know they make a .45.

[Xringshooter]

I believe the Thompson sub machine gun is a straight blowback as is the M3 "Grease" gun, Sten, etc.

Here's some good info:

http://en.wikipedia.org/wiki/Blowback_(arms)

[ChamberedRound]

There are basically two types of semiautomatic firearm recoil operations: blowback and locked-breech.

Blowback operation is a design where the gases that push the bullet out of the barrel cause the cartridge casing to be pushed back against the breech face and cause the slide to travel rearward. The barrel is typically pinned to the frame, and the recoil spring is the only component which stops the rearward travel of the slide. This type of design is very accurate, because the barrel doesn't move relative to the frame. However, blowback systems are most common only on very small caliber pistols, like 380 ACP and smaller. They are rarely seen on anything 9mm and larger, as the recoil spring that would be needed to stop the action of the barrel would be heavier than is comfortable to manually rack when loading, or when clearing a malfunction (especially in a high-stress situation).

Recoil Operation is a design most typically used on locked-breech firearms. In such a firearm, the barrel is not pinned to the frame, but connected to a frame by link pin which acts as a cam. When the gases expel the bullet from the barrel, recoil action causes the slide to travel rearward, and for a short period of time, the barrel actually moves WITH the slide due to locking lugs or grooves which hold the barrel and slide together. This extra mass allows the firearm to handle a larger force with a smaller recoil spring. As the barrel begins to move back with the slide, the link pin cams (rotates), the barrel is tilted down, and the locking lugs come free from the slide, allowing the slide to continue travel without the barrel "linked".

The locked-breech design is less accurate as the barrel isn't fixed to the frame, but the obvious advantage is that it can handle much larger calibers/pressures than blowback.

Here's an animation showing a locked-breech firing cycle on a 1911 cutaway view:



Hope all this helps.

I believe all Hi-Point handguns are blowback operated. I know they make a .45.

If they make a .45 I'll almost guarantee it's locked-breech.

To my knowledge the largest handgun caliber for which a blowback design was used and put into widespread manufacture was the Soviet-era Makarov. This pistol fired a 9mm Makarov (9x18 mm) cartridge, not to be confused with the more common 9mm Luger, which is 9x19.

As you can all see from my links, Wikipedia can (although not always) be your friend.