i went to reload some form fired brass and a few did not want to slide on the shell plate, i am assuming that it is an over-pressure sign and i pushed the load to far. i loaded quite a few combo's in a hunt for that magic load, my max powder was 46gr. i was using benchmark and varget w/ 155 a-max, or this is the 5th or 6th loading on this brass is it just wore out. this is .308, thanx
is this an over pressure sign ?
- Thread starter hershey
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Ridgerunner665
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Measure the web...it should be no more than .468" - .469"
If its more than that...you've stretched the brass with overloads.
If its more than that...you've stretched the brass with overloads.
Clark
Member
I use the extractor groove to measure the threshold of long brass life in working up a load.
If the case does not want to go in the shell holder, it may already be gone. The real problem is loose primer pockets, and when the brass deforms away from the primer pocket, it heads toward the extractor groove.
If the case does not want to go in the shell holder, it may already be gone. The real problem is loose primer pockets, and when the brass deforms away from the primer pocket, it heads toward the extractor groove.
The shell holder is used as a shell holder, it is not used as a tool with more than one function, I use a shell holder to size cases from .017 below a go-gage to infinity or for practical purposes .011 over a go-gage. If reloading was a discipline, the case head dimensions would be know before firing, discovering cases will not fit The (same) shell holder after five firings means the hand loader/shooter passed 4 opportunities to use One method to determine high pressure (or the approach of maximum load), it is said the first sign is by comparison, that is measuring the case head diameter of new (commercial) ammo before and after firing, the problem with this arrangement is the micrometer, it is suggested the blades on the micrometer be bladed, not flat and able to be read in .0001 thousands.
In your case nothing can be accomplished by measuring now after 5 firings, I have 30/06 and 308 Winchester cases that measure .468 to .471, if I was loading max and wanted to determine the effect of max loads, I would add the last .0001 (1 tenth of 1 thousands), reason being there is going to be upset (crush) of the case head for each firing, if normal upset or crush is .00025 for maximum loads, 5 firings could be .00125, without knowing the case head diameter in the beginning .00125 difference is possible without ever having been fired.
On a 308 Winchester and 30/06 the first .225 of the case head is not sized, considering military 30/06 case web is .200 thousands thick it would make more sense to use commercial brass for heavy loads, commercial brass I have measured is .260 plus, but case protrusion from the chamber is from .090 to .120. Military cases have a thick body/thin web, commercial brass
The amount of case crush is the first sign a maximum load has been reached, after that comes loose primer pockets, flatten primers and difficulty in extraction fired cases, somewhere in there will come the bolt face imprinting on the head of the case.
What could this mean to you? If you started with new cases and have some left over (unfired) the maximum number of firings could be 2 to three, or back off 2 grains and start measuring the head of the case if you are going to continue shooting maximum loads, backing off 2 grains will increase case life.
F. Guffey
In your case nothing can be accomplished by measuring now after 5 firings, I have 30/06 and 308 Winchester cases that measure .468 to .471, if I was loading max and wanted to determine the effect of max loads, I would add the last .0001 (1 tenth of 1 thousands), reason being there is going to be upset (crush) of the case head for each firing, if normal upset or crush is .00025 for maximum loads, 5 firings could be .00125, without knowing the case head diameter in the beginning .00125 difference is possible without ever having been fired.
On a 308 Winchester and 30/06 the first .225 of the case head is not sized, considering military 30/06 case web is .200 thousands thick it would make more sense to use commercial brass for heavy loads, commercial brass I have measured is .260 plus, but case protrusion from the chamber is from .090 to .120. Military cases have a thick body/thin web, commercial brass
The amount of case crush is the first sign a maximum load has been reached, after that comes loose primer pockets, flatten primers and difficulty in extraction fired cases, somewhere in there will come the bolt face imprinting on the head of the case.
What could this mean to you? If you started with new cases and have some left over (unfired) the maximum number of firings could be 2 to three, or back off 2 grains and start measuring the head of the case if you are going to continue shooting maximum loads, backing off 2 grains will increase case life.
F. Guffey
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