Re: Mod. 70, push to control feed?
I see where he said that about a loaded round working fine in his second post..
No, the 223 case is longer than the 338 case and that's not the answer, the springs are the same.
On a push feed, the minute any case clears the chamber, the case mouth will be pushed to the right into the bolt lug raceway. It rides in the raceway until the case clears the ejection port, then it ejects.
The case is held inside the bolt face when it is riding back, by the extractor and also by the bolt raceway backwards pressure, while pushed to the right side by the ejector spring. Said spring is supposed to have enough pressure to cause the round to eject when the case clears the port. A stronger spring will cause faster ejection.
While this is happening, the case head on the right side is under the extractor and the left side is still inside the bolt face left wall, but being pushed by the ejector.
The geometry of the angle of the case as it rides back, is such by design that the case head will be held on the left side until the case mouth clears the ejection port. Then the ejector spring tension causes it to jump out.
The shorter case is allowing it to come free of the left side of the bolt face sidewall before it reaches the ejection port, which drops it in front of the bolt before it reaches the port.
In other incidents with the proper designed case length, the causes for dropping the case are:
1. The extractor is broken, stoned too short, or the extractor spring is too weak to make the extractor hold the case head against the left side of the bolt face.
2. All the springs are fine, but the bolt face has been cut too deep and the slop causes the case head to go deep on the right side and out from under the extractor, which drops the case in front of the bolt.
3. The bolt face has been opened up too wide and the case head moves to the left side of the face and out from under the extractor.
4. A weak ejector spring and I do mean a weak ejector spring, but this requires much of #3 and #4 to allow the case to fall out.
In incident 1, replacing the extractor and extractor spring is the answer, not changing the ejector spring.
Incident 1A is to replace the extractor, extractor spring, and put in a weaker ejector spring.
Incident 2 may not be solveable, but is possible to fix with a fitted oversize extractor that is longer, we used to fix magnums with a 308 extractor slightly shortened.
This might require a Sako extractor to be installed.
Incident 3, generally requires a new bolt to minimum dimensions to be installed, but may be fixed with a sako extractor.
My first try would be a stronger ejector spring.
My second try on this would be to install a new tighter extractor spring, a new extractor, and extractor plunger, then maybe follow this with a weaker ejector spring.
I can see where in this case, a controlled feed action would be preferable due to the short case.