Case length question.

[diddlyv]

The amount any given case will grow is a function of how far the shoulder is set back during resizing. Move it back a lot and a lot of brass will be pushed into the neck. Move it back just a bit and just a bit of brass will be forced into the neck. Back in my high power M1A days pretty much had to trim every time I resized my 7.62 brass. I essentially sized my cases to the length of the Die as the die always made contact with the shell holder. One certainly did not want any issues chambering rounds during a match. Cases were only good for about 5 firing before one started seeing the tell tale ring indicating a high probability of a case head separation on the next firing so the brass was pitched.

I have evolved somewhat over the last 20 some odd years and now use comparators. My goal on the Grendel is to only set the shoulder back about .003 - 4. Pretty sure that will keep the case from growing very much.

When I do trim I generally like to trim to the specified length +.002 - .000 as I don't want the necks too short and don't want to waste time trying to hold +- .000 given the generous difference between max case length and trim to length.