I know there are a lot of Controlled Feed fans on this Board, so I have a question for you all:

On a Dangerous Game Rifle, how far is it allowable for the bolt move forward "without controlling the cartridge" before it is considered unfit for use on Dangerous Game and time to go to the GunSmith and get the Feed Rails adjusted? 1/4"? 1/2"? 1"? 2"?

Hotcore,

The premise of CRF is designed to ensure that a new round cannot be fed before the previous round has been extracted and ejected.

By beginning your discussion with an empty chamber, you're missing half the equation.

George

Hot Core,

Good question. A lot of it depends on the cartridge. Some snap under the claw with very little movement, some don't snap under until the bolt is pretty far forward.

With a proper CRF, the round is always controlled by opposing forces, even if it snaps under the claw late in the bolt travel.

There are 2 important things:

1. The cartridge cannot fall out of the action.
2. You cannot strip another cartridge from the magazine if you pull the bolt back before the prior cartridge slips under the claw. Regardless of how far forward the 1st cartridge is still being held by the magazine lips, the next cartridge should still be below the reach of the bolt face. Much of this depends on proper magazine and follower dimensions for that particular cartridge.

Controlled feed means that the cartridge is controlled at all times, be it by magazine, feed rails, follower, extractor, bolt face or chamber wall. As long as it is controlled from the instant you load the cartridge into the magazine, up until it strikes the ejector, it is controlled feed. The cartridge will always be controlled by at least two surfaces exerting opposite pressure.



Under these circumstances you should never have a loose cartidge or a double feed. If you do, than something is out of adjustment. While it is nice to see a cartridge snap under the claw with only an inch of bolt travel, it is not always possible. Some cartridges will have to be pushed a bit further, often until the bullet touches the ramp.



If you ever want to see CRF perfected, look closely as you feed a cartridge through an original (1903-1969) Mannlicher-Schoenauer. It will bring a tear to your eye.





Post Script



I just checked a few of my 98's in standard size cartridges (2 @ 8x60, 2 @ 7x64). The cartridge leaves the control of rails at the half way point of bolt travel, slipping under the claw. If I pull the bolt back before that, the first cartridge is still held in place by the rails and ramp, while the second cartridge is too low for the boltface to engage it. Perfect.

MacD37,
Just a few points for fun. Lord know's I've had my oversights corrected here.
I believe you mean Short Stroking. Short Shifting is a common phrase in trucking and refers to either clutchless shifting or skipping a gear. The latter is done when the truck is not carrying a load; therefore, going from 1st to 3rd, 5th, etc. is less effort than working through the entire range.

I was always under the impression that the "short stroking" was the sole domain of the CRF and it refers to the instance when the bolt was not taken back far enough for the mechanical ejector (usually a fixed blade operating through a slot in the bolt face) to "punch out" the empty case. Since the bolt doesn't come all the way back, the empty is not ejected, and the Mighty Claw extractor doesn't let it go anywhere. When the bolt is slammed forward, and the trigger pulled, the dreaded "click" is heard. That is "Short Stroking" The source of the name is the cause of the problem. It is not easy to do this, but when you're life's on the line, breathing can be difficult too.

The push feed actions can also be "short stroked" but with different attributes. In the PF action a "plunger style" ejector is pushing the case toward the ejection port, and only the extractor and the chamber are holding the case in a line with the bore. As soon as the mouth of an empty case clears the ejection port it "springs" out. However, if the bolt is not drawn all the way back, a new round will not be stripped from the magazine, thus the bolt is closed on an empty chamber, and that dreaded "click" is heard.

I believe the circumstance you attributed to the PF action is called a "double feed", and is indeed easy to do just as you state. However, it is a rare occurence that a hunter is under stress during the initial loading. The initial round is usually loaded in a very slow, exacting and quiet manner. Yes, people have cycled every round out of a magazine, without pulling the trigger, but this is no fault of the action design.

MacD37, I've learned a lot from you over the years, so I hope you will take this post as it is intended.

Safe Hunting.

Clint

Hot Core,

1. I would say that there are numerous designs that are capable of providing controlled feed. The goal is to never have a loose cartridge, and to never have to the bolt face able to access two rims at the same time.

2. I think that when the rim slips under the extractor depends largely on the size and shape of the cartridge. I would not try to hold a .22 Hornet and a .500 Jeffery to the same standards. I don't think it is that critical to performance, as long the above goals are met.

That being said, I put rifle designs into three categories.

1. Mannlicher-Schoenauer
2. 98 Mauser
3. Everything else