first carbine unboxing

[Matt_X]

Re: Failures to feed and Magazine
I think you've already narrowed this down. If all 3 mags are sitting low and are loose, then investigate the mag catch. Another thing that might be causing a greater distance would be the trigger housing sitting low. I would think that would take a severely worn or incorrect trigger housing pin.


Re: Point of impact at 25 yards.
I don't know if 4" up is excessive, but POI at 25 yards should be somewhat above the POI for factory sight set for 100 or 150 yards.
We've been discussing this a bit on the CCC forum.
IIRC the 1953 technical manual has a 25 yard sighting target as well as a 100 yard.
The acceptable impact area on the 25 yard is shift up 3/4" from the 'bullseye'.
Both targets are to be used with the point of aim at the bottom edge of the bullseye.
Although using a 6 oclock hold is a bit more complicated to figure ballistics using one of the on-line calculators, if we use a center of target POA we can see that for a zero at 100 yards, there is a about .4" rise in POI at 25 yards using a typical 110 gr exiting around 1900 fps.
If the zero is 150 yards, then its closer to 1" rise at 25 yrds.

Here's the theoretical trajectory at three sight settings using Federal's on-line calculator and their factory load info.
Attachment 120987

These on-line calculators may make some assumptions about sight radius etc that may effect the results of the carbine. But I think its useful for seeing the effect of changes in velocity, sight hight, etc.