Controlled feed vs Push feed?

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wbwanzer

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Can someone explain the difference between 'controlled feed' and 'push feed' bolt actions for me?

I've already got a thread going about a CZ 527 American that I'm considering. Per CZ's site "the CZ 527 is a true micro length Mauser style action and features controlled round feed". It seems that a lot of bolt actions are 'push' feed. What is the difference? Is controlled feed better? Is the Mauser action considered to be superior? It sounds like a 'better' action to me, but I really know nothing about it.

If anyone could shed a little light on this it would be appreciated.

I'm sure that I don't need the most sophisticated rifle action, but it is appealing in the same way that a Porsche or Ferrari engine can be more appealing to a car enthusiast than an American pushrod engine. If I buy the 527, and I buying a superior action? Or is 'controlled vs push' more like Ford vs Chevy? No right answer.

Thanks for any help.
 
Control feed is where the bolt when pushed forward, pushes the back of the cartridge forward and into the breech. As the bolt continues its forward motion, the cartridge rim is secured by the claw extractor, minimizing the move of the cartridge and preventing it from becoming offset and jamming in the gun.

Push feed is where the bolt when pushed forward, pushes the back of the cartridge forward and into the breech. Unlike the controlled feed, the cartridge does not grab hold of the cartridge rim. If held sideways or even upside down, there is a chance of the cartridge becoming offset and jamming in the action.

The older Mauser 98 and pre-'64 Winchester Model 70s both use the controlled feed system. The Rem 700 and Savage 110 type action uses push feed.
 
Controlled Round Feed (CRF) "holds" the cartridge on it's way from the magazine to the chamber. Push Feed (PF) simply pushes the cartridge into the chamber without holding it.

With CRF, you could cycle the action and feed a round while hanging upside down like a bat, if you tried that with PF the round would fall to the ground. Some maintain that this feature makes CRF better for dangerous game, where you want more assurance that the round will make it to the chamber.

Personally I don't worry about it. In the grand scheme of what matters to me when buying a rifle (fit, customer service, trigger, accuracy, cost, etc...), CRF vs PF is way way down the list. I've never encountered a situation where CRF vs PF would have made any difference, but I'm less experienced than most here.
 
With the controlled feed, as the cartridge rises up as it's stripped from the magazine, the rim slides up and behind the extractor and is held against the bolt face as it's guided into the chamber.

A push feed strips the cartridge from the mag and pushes it into the chamber and the extractor snaps over the rim as the bolt locks into place.

While early Ruger M77s had claw type extractors, they were not controlled feed. They were push feed. Ruger later modified their rifles to controlled feed.

The only time a push feed won't feed held upside down or sideways is when the bolt is worked slowly. Work it fast, there's no problem. The magazine controls the cartridge until is at least partially pushed into the chamber
 
As the others have said, on a crf the cartridge is held very securely... but what they aren't saying goes is, also with a crf action you can drop a round in the action and bolt forward like bench rest shooters do... you have to 100% push the round down into the mag or it will jam up the bolt upon trying to close the action
 
The controlled feed helps prevent double loading and that is especially important when hunting dangerous game. If someone gets nervous when operating a push feed and pushes the bolt part of the way forward and then pulls it back and pushes it forward again two cartridges will have come out of the box magazine and jam in the chamber. In this situation the bolt can't be closed until one of the cartridges is removed and even then the person working the bolt has to push down on the cartridges in the box when operating the bolt to make sure a 3rd cartridge doesn't come out of the box magazine.
 
The push feed action became popular in the 1950's and 1960's because it reduced manufacturing costs. Remington could made a Model 700 much cheaper than Winchester could make a Model 70 because they used push feed actions, cast receivers instead of forged receivers, round bottom receivers, and actions without hinged floorplates. The public has accepted these rifles because many of them are cheap to buy. I personally like the controlled feed actions and don't own any push feed rifles.
 
If you reload or plan to, a CRF action will restrict you to magazine length cartridges or shorter. You will not be able to hand feed over length cartridges without extraordinary effort.
 
As Mistwolf noted, the only time you'll experience a problem with push feed is if you do not maintain sufficient forward pressure on the bolt once the cartridge is free of the magazine lips. Most notably, this would happen if you were trying to feed the round in "slow motion"; as the rim leaves the feed lips, it will pop up. If the rifle is reasonably level, the cartridge will drop back down and rest on the feed lips as it continues to be pushed into the chamber. If the rifle is significantly canted, however, the cartridge may become misaligned or even fall out. Having said that, trying to work a CRF weapon super slow can also cause problems. Most repeating action designs rely on some amount of bolt or slide velocity for proper, smooth feeding.

The most notable push feed weapons are probably the two most prolific centerfire rifles in America; the Remington 700 (push feed is also used on the model 7, 673, 600 and others) and the AR.

The push feed action became popular in the 1950's and 1960's because it reduced manufacturing costs. Remington could made a Model 700 much cheaper than Winchester could make a Model 70 because they used push feed actions, cast receivers instead of forged receivers, round bottom receivers, and actions without hinged floorplates. The public has accepted these rifles because many of them are cheap to buy. I personally like the controlled feed actions and don't own any push feed rifles.
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Giant load of hogwash. Remington 700 receivers are machined from steel round bar stock. Ruger is the one who uses castings, and they are not inferior, as the design accounts for the slightly lower strength of the material. Big green has also always offered hinged floor plates, just not on the cheapest models.
 
If I was using a bolt action rifle to go after dangerous game I would want a controlled feed action. There is no disadvantage. Not only is there an advantage to feeding a round into the chamber there is typically an advantage of having more extractor surface in contact with the cartridge. That being said I would never refuse to use a high quality non-controlled feed rifle. Modern military rifles are subjected to far more abuse from weapon heating and fouling than sporting arms and they typically do not have a control feed action.
 
I hate to spoil this orgy of "controlled feed" superiority, but my Remington 700 Police rifle, or whatever they call it, will reliably feed cartridges from any angle, even upside down. I will admit to the double feed issue being a problem; if you do not manipulate the bolt correctly. So be familiar enough with your rifle to use it properly!!

I have never hunted dangerous game in Africa, but I can read accounts of those who have. It would seem to me that the three position safety had gotten more people mauled than any failures of the "Push feed " rifle.
 
If you look at the rise in popularity of plastic tipped bullets it can be largely attributed to push feed bolt actions. A lead tipped spitzer bullet cycled through a a push feed action will often show signs of deformation at the tip. The plastic tip is more durable and isn't visually compromised when it is forced in to contact with the feed ramp of the chamber.
 
I will admit to the double feed issue being a problem; if you do not manipulate the bolt correctly
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That can happen with any firearm that has a spring loaded magazine, though designs that have longer feed lips are less prone, as are designs that have the feed lips machined into the rigid receiver rather than relying on sheet metal mag lips to retain cartridges.
 
If you look at the rise in popularity of plastic tipped bullets it can be largely attributed to push feed bolt actions. A lead tipped spitzer bullet cycled through a a push feed action will often show signs of deformation at the tip. The plastic tip is more durable and isn't visually compromised when it is forced in to contact with the feed ramp of the chamber.
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I think you misunderstand the differences in the action types. Both types shove the cartridge into the chamber in the same manner, CRF just grabs hold of the rim as it leaves the feed lips, before the round fully chambers, where push feed extractors do not engage the rim until the very last 1/8" or so of bolt travel.

Nosler really pioneered the polymer tip in the early '90s, and it's development had a lot more to do with controlling expansion than preventing tip deformation.

If your goal really is to not have anything touch the bullet nose during chambering, a CRF may be the type that's off the table, as many of them must feed from the magazine. Push feed design uses an extractor that snaps over the rim when the cartridge is chambered, which is always conducive to single loading. Some CRF rifles are relieved for the extractor to be able to do this, some are not.
 
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you have to 100% push the round down into the mag or it will jam up the bolt upon trying to close the action
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Kinda, sorta true 100 years ago, but I know of no modern CRF rifle where this is the case. The original Mausers manufactured during WW-1 were so. But by WW-2 there were ways around the problem and all modern CRF rifles will feed just fine with rounds simply dropped into the action and the bolt closed.

I hate to spoil this orgy of "controlled feed" superiority, but my Remington 700 Police rifle, or whatever they call it, will reliably feed cartridges from any angle, even upside down
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This is also 1/2 true. A PF rifle will FEED just as reliably as a CRF rifle. But a CRF rifle is still superior because it will EXTRACT and EJECT far more reliably especially under harsh conditions. The term "Controlled Round Feeding" has caused a lot of confusion. CRF has never been any better at FEEDING. Even the issue of double feeding a round is related to more reliable extraction than feeding. A PF rifle will not extract or eject a round until the bolt is completely closed. If ANYTHING happens to interrupt this you have a hopelessly jammed rifle. CRF will extract and eject a loaded or empty case at any time the bolt is pulled to the rear clearing the chamber for another round.

The extractor and ejector on PF rifles are tiny and by design much easier to fail because of dirt, snow, mud, ice, or even powder residue in the action. CRF extractors and ejectors are much larger and far more fool proof.

The reason CRF is preferred for dangerous game has a lot more to do with the fact that the rifle is simply much more likely to work even after being exposed to harsh dirty conditions than more reliable feeding. Having a rifle fail while shooting at a whitetail is far different than having it fail when shooting at an animal that will attack and kill you.

Years ago hunters in Africa or other remote places often were in the bush for weeks, even months at a time where proper care of rifles was much more difficult. CRF rifles proved they were better able to work in those conditions. Same with muddy battlefields in WW-1 and WW-2.

Make no mistake, that is still true today. The problem is that most people will never put themselves or rifles in a position to ever notice the difference. It is like comparing a Ford Explorer to a military Hummer. For 99% of drivers the Explorer is more than adequate for their off road needs. That doesn't mean it is as capable as the Hummer.
 
I've owned my share of Remington series rifles M788, M700 and 40X and never experienced a chambering problem.

When USRA reintroduced the M70 with controlled feed the OEM, MIM claw extractor on my two examples were problematic. I replaced them with after market bar stock machined extractors.

I'll admit to not doing backflips and barrel rolls and or other gymnastics, thus I've never had a problem with the push feed bolt action rifles.
 
My point about the difference between a early Winchester 70 and the Remington 700 receivers comes from the added expense Winchester used to produce the receiver. A steel producer explains the products they offer as follows: Steel is an iron alloy that can be produced in a variety of grades , shapes and sizes. Grade rating refers to the chemical composition of the alloy, and, among other factors, affect it's physical and performance properties. Value added forging services include cold and hot forming and heat treatments to produce the desired properties in forgings.
 
If you observe a CRF bolt engage the rear of a cartridge, the extractor captures the rim of the cartridge and maintains a level to the action travel of it into the chamber without the bullet deflecting off of the feed ramp.
To illustrate the difference take a fired case and load it in the magazine of a push feed action and cycle the action and observe the angle of the case during the process.
 
If you reload or plan to, a CRF action will restrict you to magazine length cartridges or shorter. You will not be able to hand feed over length cartridges without extraordinary effort.
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I have a pre-64 Model 70 Winchester and two M1903A3 Springfields -- these are controlled round feed rifles, and all with all three, you can single load and close the bolt with no problem.

I also have an M94 Swedish Mauser, and that rifle CANNOT be single loaded -- you have to strip the cartridge from the magazine.
 
I stand corrected so far as single loading many CRFs. A Swede and a Gewehr 98 left me with an incomplete education on the issue.
 
i have used both types on three hunting trips to africa, shooting dikker to cape buffalo and i,m still here and going back next year. eastbank.
 
Push feed has been around a very long time. The GEW 88 uses a push-feed bolt, as does the Mosin. Most commercial actions use push-feed. It is very reliable to use.
 
My point about the difference between a early Winchester 70 and the Remington 700 receivers comes from the added expense Winchester used to produce the receiver.
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Cite a source for this claim. A credible one.

And then explain, without pontificating, what benefits the "extra cost" provides. More expensive ≠ better.

A steel producer explains the products they offer as follows: Steel is an iron alloy that can be produced in a variety of grades , shapes and sizes. Grade rating refers to the chemical composition of the alloy, and, among other factors, affect it's physical and performance properties. Value added forging services include cold and hot forming and heat treatments to produce the desired properties in forgings.
Click to expand...

If you wanna get into metallurgical debates, I'm game. But if you don't know the basic properties of some common steels, say, A36, 1018, 4140, D2, S7, etc. off the top of your head, you might think twice.
 
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