What is a controlled round feed?

[Anteater1717]

What is it ?
What does it do?

 

[PercyShelley]

In the context of bolt action rifles, it means that due to the extractor design rounds cannot be fed singly into the chamber; they must be stripped from the magazine.

Claimed advantages are better reliability and accuracy.

 

[The Lone Haranguer]

Finally, a rifle question I can answer

Visualize a loaded magazine and the bolt to the rear. As you push the bolt forward, the extractor immediately grabs the cartridge rim, thus holding the case against the bolt face, where it stays as you push the round into the chamber. Put another way, the round is grasped by the extractor through the full stroke of the bolt. After the round is fired and you draw the bolt to the rear, the case is still held by the extractor until it hits a fixed blade ejector and is flipped clear. The best-known example is the Mauser 1898. Being originally designed for military use, the rifle must feed under combat conditions - turned on its side, full of mud, improper manipulation (e.g., "short-stroking") under stress, whatever.

A push-feed bolt (e.g., Remington 700) merely pushes the round off the top of the magazine, with nothing actually grasping the round. When the round is fully chambered the extractor will then ride over the rim and snap into place. It will usually have a spring-loaded plunger ejector within the bolt, which presses against the case head and flings the case clear when it clears the chamber.

 

[Float Pilot]

Basically, Mausers, Springfields (a Mauser Clone) The older style Model 70 Winchesters, the Kimbers, CZs and etc...
They have a big extractor claw that the rim of the cartridge comes up behind while being pushed from the magazine.
So even if you were upside down and moving the bolt slowly, the cartridfge cannot dislodge itself from the bolt face. Even if you stop pushing the round forward and come backwards for some reason.

Many folks believe this is a must for hunting dangerous game.
It is not always fool proof. The older Mausers and Model 70s were made by real rifle crafters. Some of the modern controlled feed guns have problems because the timing of the magazine rails is all goofed up. This causes the round to be released at the wrong point and it is not captured by the extractor claw.

Push feeds, usually have a more recessed bolt face. If properly operated they usually are just as reliable.

Many push feed bolts (like the Model 700 Remington) totally enclose the cartridge head.
Many push feeds are known for their superior accuracy. This may be because of the way the bolt supports the cartridge or because many are a newer design and have a flat base on their action which makes them bed into the stock easier. That is why push feed M-700s are the bais of most sniper rifles.

Yeah, I actually got photos to stick.... and I see you already had a cuple good answers while I was taking pictures.

Attached is a M/98 Mauser Controlled-Feed bolt face and a M-700 Remington Push-Feed Bolt face.

 

[USSR]

In the context of bolt action rifles, it means that due to the extractor design rounds cannot be fed singly into the chamber; they must be stripped from the magazine.

Not necessarily so. My FN SPR (Winchester CRF action) can be singly loaded in the chamber, as can all Springfields.

Many push feeds are known for their superior accuracy. This may be because of the way the bolt supports the cartridge or because many are a newer design and have a flat base on their action which makes them bed into the stock easier. That is why push feed M-700s are the bais of most sniper rifles.

The Remington M700 has a round bottom on the action; the Winchester M70 (both pushfeed and CRF) have a flat bottom on the action. The Remington M700 action is the basis for many sniper rifles because it is easier for gunsmiths to work on due to it's tubular design.

Don

 

[dagger dog]

Make sure your in the correct place to carry this out, load the magazine ,rack the bolt back, invert the rifle if the round falls out, it's not a controlled round feed.

The Mauser Bros. produced their rifle for battle, the soldier may need to be moving as he reloads the chamber of his rifle and the controlled round feed assures that the round stays in position to be fed into the chamber under most conditions found on the battle field.

All modern bolt actions are grandchildren of pappy Mauser, but all of gramps babys are not used under battle conditions so you have,controlled feed, push feed, controled push feed, the latter found on the Winchesters.

All these different actions have their advantages and disadvantages.
It's up to the buyer to pick the one that best suits his crteria.

 

[rcmodel]

Not necessarily so.

+1

All Model 54 and Pre-64 Model 70 Winchesters, and most 98 Mauser's built for sporting use can be loaded to full 5+1 capacity. (Magnum calibers = 4+1 or 3+1)

Load 5 in the box, hold them down with your thumb, and drop another round in the chamber.
Then close the bolt.

The "controlled round" rotating extractor will snap over the rim with a little more pressure on the bolt handle.

The extractor is not prevented from snapping over the case rim until the bolt is fully locked.

Many military 98 Mauser's did not have sufficient taper ground on the front of the extractor hook to allow this.
Whether by design, or shoddy workmanship is open to question.

I've seen some that will, and some that won't.

rcmodel

 

[PercyShelley]

Not necessarily so. My FN SPR (Winchester CRF action) can be singly loaded in the chamber, as can all Springfields.

I stand corrected, thanks.