Originally Posted by roninflag
i resize only enough that i do not bump back the shoulder. there should be a black ring on the case neck showing how much more you have to go. on a 300 h&H i would have it come around 90%-95 % down the case neck.
I know this is a popular way to resize fired cases, but when I talked with folks who shot the .300 H&H in long range matches, the ones winning and setting records had the following comments about sizing fired cases.
Any fired case sizing tool and technique that doesn't set the fired case shoulder back a bit typically ends up making the case headpace (head to shoulder distance) at or a bit longer than chamber bolt face to shoulder distance. This ends up causing the bolt to bind as it's closed on a chambered round. If the bolt face isn't squared up with the chamber axis, binding is more common and accuracy suffers. Problems are caused by the bolt head long locking up in the same place for each shot and that changes the amount and direction of the barreled action's whip while the bullets are going down the barrel; they all don't leave at the same angle relative to the line of sight when fired.
The fired case shoulder needs to be set back a thousandth or two so the bolt won't bind closing on a loaded round. This lets the bolt close to the same place for every shot. The barreled action whips more consistantly and accuracy is better. Note the benchresters have to resize their cases that bind up when the bolt's closed, otherwise their accuracy degrades a bit.
Those who've measured case neck runout on resized cases have seen straighter neck better centered on bottleneck cases when full length sizing dies are used sizing all of the neck and setting the shoulder back a bit. This method holds the case body and shoulder in place while the entire case neck's sized down. Sizing the case neck down just enough without expander balls using dies with correct neck diameters typically do a better job at this than any neck only sizing die or partial neck sizing with a full length die.
It was interesting to hear these folks state tha new .300 H&H Mag cases shot as accurate as properly resized fired ones as long as the bullet was seated out long enough to gently push into the rifling when chamberd.
Food for thought even if you think it all a bunch of baloney. I've shot belted magnums enough to see the realities of this.