Why a "controlled" feed?

[MattyD380]

From Stephen A. Camp's blog:

"Ideally, most autos strip the round from the magazine with the rear of the cartridge sliding upward against the breach face. The extractor claw slides over the rim via the extraction groove. The Makarov does not do this. It has a projection at the bottom of the breech face that prevents it. The extractor gets to the cartridge rim by jumping it."

https://hipowersandhandguns.com/MakarovBersa.htm

Looking at the bottom of my Mak's breech face, you can see how it's impossible for the case rim to slide up under the extractor claw, as Mr. Camp explains. It just plows straight into the chamber, up a very shallow feed ramp. And apparently the massive claw has no problem slamming over the case rim.

Why aren't more pistols designed this way? It seems to eliminate a lot of variables and angles that are more likely to cause feeding issues. The 1911's delicate ballet of extractor, feed ramp and feed lips seems unnecessarily complex, comparison. Obviously, there's a reason--or it wouldn't be on, like, just about every other pistol in existence. Maybe it's because tilt barrel pistols generally require the round to feed at a steeper angle... and it's easier for the rim to slide up breech face as it feeds? But that's just a guess.

[ReverendMeat]

Possible damage to the extractor maybe?

[M2CattleCo]

The 1911's ballet is only delicate when built incorrectly.

Which is more common than not.

No clue about any of the other stuff.

[Chuck Whitlock]

Why aren't more pistols designed this way? It seems to eliminate a lot of variables and angles that are more likely to cause feeding issues. The 1911's delicate ballet of extractor, feed ramp and feed lips seems unnecessarily complex, comparison. Obviously, there's a reason--or it wouldn't be on, like, just about every other pistol in existence. Maybe it's because tilt barrel pistols generally require the round to feed at a steeper angle... and it's easier for the rim to slide up breech face as it feeds? But that's just a guess.

You may have answered your own question. The Mak has a fixed barrel like a PPK, as opposed to the Browning tilt-barrel design. None of these individual attributes exist in a vacuum. In order to reliably snap over a rim. the extractor design needs to be beefy, robust, and incorporate a spring and pivot pin. One thing guiding the design of the 1911 was the ability to be detail stripped in the field without tools.

[Catshooter]

The controlled feed has also been used in rifles. The reason: it's more reliable. The cartridge is captive from the mag to the chamber, all the way. With the firearm held still and level feeding is easy. But turn it on it's side, move it around or bump it during feeding and the round can jump out of control. No big deal if your target is paper. Controlled feed does just exactly that.


Cat.

[Navin Johnson]

Rifle CFR does not have the claw jump the rim as described above. The above is push feed and the claw is slammed over the rim. Mak's are rumored to be reliable so it works I guess.

[Navin Johnson]

The controlled feed has also been used in rifles. The reason: it's more reliable. The cartridge is captive from the mag to the chamber, all the way. With the firearm held still and level feeding is easy. But turn it on it's side, move it around or bump it during feeding and the round can jump out of control. No big deal if your target is paper. Controlled feed does just exactly that.


Cat.

A properly designed PF rifle magazine controls the round until it is part way in the chamber. I have seen PF bolt gun feed inverted while cycling the action very slow. I think the biggest benefit to CFR is the huge extractor for reliable cycling/extraction.

[Catshooter]

You are quite right.


Cat

[Navin Johnson]

You are quite right.


Cat

Fa sho but it is designed to feed from the mag. Apparently the Mak. Is designed to push feed and then jump the rim.

Sorry I think I'm replying to something else.

[MattyD380]

Thanks for the insight. I was asking purely out of curiosity. It's a fairly unique design attribute in pistols. And for whatever reason, it doesn't come up much. Since the Mak is known for reliability, you'd think more designs might be taking that same approach. Just thinking about it from a "less can go wrong" perspective, seems like a no brainer... just slam a round in the chamber and call it a day.

PP guns and Sig P230/2s both use a controlled feed, as far as I can tell. And, interestingly, both designs seem to succumb to fouling after a few hundred rounds. I've never heard of this with a Mak. I wonder if the push feed mechanism was seen as a way mitigate the extra fouling generated in a blowback system. I can't see any amount of soot stopping a Mak's extractor. Granted, I haven't put more than about 120 rounds through my PM at a time, but I had a P230 that would choke on flat point stuff after about 100 rounds. I've read they will start to choke on everything after about 200 rounds. I never shoot my current P230 that much, so it's really a moot point. But suffice to say, I'd put my money on the Mak being able to stand up to higher round counts between cleanings. I'm pretty sure the P64 also uses a feed system like that of the PM.