Blow-back vs. locked breech: Is one inherently better?

[Bapak2ja]

In another thread I started to investigate the merits of a Bersa Thunder Compact vs. a Colt Mustang, some folks raised the issue of blow-back verses locked breech pistols. The two key comments are given below.

Number 1: "I'd expect the Colt to be a bit better made in terms of the pride-of-ownership niceties, but blowback is a more reliable operating system than locked breech, so I'd expect the Bersa to have a bit of an advantage in potential (key word) reliability."

Number 2: "Just curious, but where does the idea that blow-back guns are more reliable than locked breech guns come from? Growing up, the conventional wisdom said just the opposite. Blow-back guns, while reliable, require much narrower pressure/time curves to operate properly than a locked-breech gun. As caliber in creases ​[sic], the weight of the slide, and the power of the recoil spring both increase, as well. This makes the guns top-heavy, and hard to cycle manually. Then again, blow-back guns can be finicky about bullet weights and velocities to a much greater degree than locked-breech guns."

This is an interesting and unexplored issue for me. I welcome your comments.

 

[88E30M50]

I cannot offer scientific data to support one over the other type, but my experience has been that the locked breech is an easier gun to shoot than a blowback gun. I've owned multiple Bersa 380s, a PPK, a Sig P238 and a P938. The only reliability issues I've had with any of them were with disconnectors in the Bersas and FTF issues with the PPK. But, the feel of the P238 as compared to my Bersas was very different. The Bersas had a much sharper recoil than the P238. The P238 is actually a fun little gun to shoot for an extended period of time where as the Bersas and PPK are not. They're not awful like a PF9, but just feel different than the P238. Even my little P938 is a fun gun to shoot and I believe that's because the locked breech design gives a softer feel than the blowback design does.

Either design should function reliably if manufactured properly, maintained properly and used properly.

 

[russc2542]

From how it's worded, I think the speaker means reliability in terms of time until breakage. In that sense, the locked breech has more moving parts which could fail to function or fail structurally. While there is some merit to the logic, the counter point is that the lockup/unlocking action slows down and softens slide movement so the action is less violent. Third, straight blowback guns tend to be cheaper and made more cheaply contributing to parts failure before a better made locking-action (in those cases. obviously there are nice blowback guns and cheaply made lockup guns). Most decent pistols with halfway decent maintenance will outlast what a normal person does to it. even when they do fail it's seldom related to the lockup components... for one thing they're usually large, solid, and over-engineered to prevent it: there are too many weaker components to fail first.

Using reliability as a word for the range of conditions it'll function in, I'll agree that locking-action firearms tolerate a wider variety of ammo power and weight.

Locking actions generally are softer shooting because some of the energy is used to operate the locking function which breaks the start/stop events into several pieces. That's why you seldom see a straight blowback pistols larger than .380.

only straight blowback guns I've had are a Beretta 84FS and a Chiappa MC14. Neither is snappy like a little polymer gun but you do feel it as much or more than a locking-action 9mm of similar dimensions, even if it is just a .380. limp-wrist even a little and it jams. Ammo isn't the right OAL, jams. too little power: jams. too much and the slide bottoms out on the frame, which you REALLY feel. The beretta is a lot better overall but still not my first choice of a gun.