223 headspace

[Nathan]

Put a fired(from your gun) case in your Wilson gage. What does it measure?

Your sized cases should be fired -0.003" for an AR on average. You will need to work on your lube amount to be consistent.

[Unclenick]

Fretless33,

You can ask Hornady, but I'm pretty confident that because the dies used in their progressive press are the same dies they sell for use in presses using standard shell holders, the plate will be designed so that when the ram is all the way up and the FL die has been correctly adjusted to have full contact with the shell holder when a case is forced into it, only 1/8" will be between the case head and the mouth of the die. All standard dies are designed to push the case shoulder back within SAAMI new case specifications when that 1/8" gap is present. Below shows how this looks on a .308 Case, whose large primer pocket is typically 0.126" deep. The small rifle primer pocket is typically 0.113" deep, but that's only 0.013" shy of how far down the side of the case the full length die goes. Below that is an exaggerated illustration of how sizing affects a case.





Folks talking about adjusting case headspace with die adjustments generally have chambers that are longer than SAAMI minimum, and don't want to size the shoulder all the way down as far as the die is capable of taking it when that 1/8" is maintained. Their chamber will handle a longer-than-standard case headspace. Usually they target a headspace just a thousandth or two shorter than the case is after firing in their chamber. Using that longer case headspace means they work the brass less and get improved accuracy. In other words, they want the gap between the casehead and the die mouth bigger than 1/8". They don't want the die in full contact with the shell holder. So they adjust the die OUT to make the case headspace come out longer.

You can, as others have described, sometimes get a little more sizing by tightening the die. This is to be sure the press isn't stretching and giving you a small gap between the die and shell holder. But once the die's been tightened enough to remove that, you don't get further sizing.

If you need shorter headspace than you can get with a standard die at any adjustment, the only solution I am aware of for progressive reloading is to have the case mouth ground back by the number of additional thousandths of shortening you are looking for. On a single-stage press you can run the case into the die more than once, counting to five with the ram up to let the brass relax a little. Doing this a couple of times after the initial sizing, rotating the case 1/3 turn inbetween, will you get another couple of thousandths of an inch of shortening. For even more, you can decap the case, remove the decapping pin from the die, then size again with a feeler gauge jammed between head and the bottom of the shell holder. You can almost always fit at least a 5 thousandths gauge in and get that much additional shortening.

[fretless33]

Thanks guys/unclenick...you have been incredibly helpful and informative!