Here is a comment by Ted on the extractor and control round feeding in another thread. I know I was just looking at this thread, and missed the others.
From Ted:
In general, an action is considered to be controlled round feed (CRF) if its extractor is capable of engaging a cartridge on its way out of the magazine and then pulling that cartridge reward for delivery to the ejector without the need to rotate the bolt closed as one would need to do in a push-feed action such as a Rem 700.
Pushing the bolt forward as slowly as possible and expecting the same result as one would get had they pushed the bolt forward at normal speed is senseless because cartridge inertia matters.
The advantage offered CRF actions is a reduction, in the likelihood of double feeding the chamber which would otherwise cause a jam. This tends to happen during times of stress, such as during timed competitive events. Again, it CRF reduces the risk of double feeding. It does NOT eliminate it.
The degree to which the likelihood of double feeding is reduced depends on the magazine and its feed lip geometry, the diameter of the cartridge body, the diameter of the bolt, the shape of the extractor hook, and the position of the cartridge shoulder along the length of the cartridge, the speed with which the bolt is cycled, the width of the cartridge extraction groove, and more. Variations in any of these will affect CRF reliability.
While designing both the Nucleus and the Mausingfield, I never once assumed that CRF functionality would be necessary when running a bolt as slowly as possible in an attempt to capture the case being forced under the extractor when the forward motion of the bolt is purposely stopped an instant after the mag has released it. That said, we can create the conditions for that to happen, or not happen, but that would be a stupid waste of time. And that's true of any CRF action, Mauser 98 included. Just because I can cause a certain Mauser 98 to fail to engage the head of a certain cartridge by running it in a certain manner would not lead me to conclude that the M98 is not a CRF action. And that's saying something because Mauser rifle were built as cartridge specific rifles. Moreover, anyone who has every built custom rifles on M98s will tell you that mods are required to get reliable CRF functionality.
If you want to capture controlled round feed on video, record the bolt cycle at normal speeds (fast) and replay in slow motion. I'll leave that up to someone else.
Oh, and one last point. Never write anything in a public forum about a bolt action until after you have come to understand the Mauser 98. I can't stress that point enough.
Ted
Theodore Karagias
President
American Rifle Company, Inc.
We Engineer Accuracy
