Originally Posted by Prairie Dog50
I can see that what all of you guys are saying makes a-lot of sense. I forgot to mention that this is all once fired brass or brand-new full length sized brass all of which is Winchester. So please by all means correct me if I'm wrong but I don't think its the brass being too long. However somebody mentioned something about the O.A.L. of the cartridge being to long; I think this very well could be a possibility. I have noticed that when using the Hornady O.A.L. set screw type gauge the case that I bought that is drilled out in the back end and meets sammi specs seems to fit into the chamber quite tightly without any wiggle room. Because of this I might have gotten a false reading due to the fact that I thought I had jammed the bullet into the lands when in reality I didn't have the case properly seated with the O.A.L. gauge all the way into the chamber. One other question I have is when measuring O.A.L. with a bullet comparator attachment, is there a rule of thumb as to how much pressure to exert onto the calipers with my thumb??? This could be part of the problem as well. I don't push as hard as I can but I do push past the natural stopping point of the measurement. To me this is a gray area in reloading that is not often covered in the reloading manuals, so as a re-loader who is still learning I guess I'm in the dark on this one.
If you are not sure that you are getting a good measurement with the gauge, try the old way.
Take a sized case and insert the bullet you want to use, long and very carefully insert it in
the chamber until the bolt stops(No pressure) then seat it a little deeper .005 to .010 at a time
measuring COL as you go. when the bolt will close with little or no effort measure the COL and
subtract .003 to .005 to this dimension because even though you just barely touch the rifling it
will engrave slightly.
This will be your "Actual" COL and with this length start by reducing COL by .020 to start load
develoupment.(Note if the bullet is touching the rifling you need to start at or below minimum
I weight sort all of my brass and end up with several that are out of batch range and I use these
to make my COL gauges for different bullets and leave them in my die sets (Painted red and with
no primer). These are set at the final COL that the load performed best with that bullet.
I always start .020 off the lands and work up in pressure and velocity and when the most likely
load is found THEN I adjust the COL closer or farther from the lands for accuracy by .005
Just the way I do it to optimize the accuracy, velocity and pressure.
J E CUSTOM