I'll probably feel like an idiot for this but here it goes...I've been reloading for a while but only neck sizing and full length. Now for the first time I'm trying to just bump the shoulder back a little and I can't seem to get it figured out. I'm using a Lee full length die in a Rock Chucker. 7mm magnum. First I set the die up like normal...1/4 turn more after it hits the shell holder. That bumps the shoulder back .012. I wanted to try getting that to .002, so I figured I'd just back the die out until I get there. But as I do this nothing changes. I'm using a Hornady headspace gauge to check this. I've searched through all of my manuals and everywhere else I can think of but I've had no luck. So please tell me what I'm doing wrong here.

Thanks

I normally start high (die not making contact with shell holder) and lower the die down, instead of screw it down all the way first, and back it out. It takes very small increments once you find where the setting is. It does take some trial and error. Once you size a piece of brass a few times, I will set it aside and get another piece. Then go back and size the other one's when you have it set up where you want it.

Also, any time you do a partial sizing, keep your rifle there to chamber check the brass. Sometimes it will not chamber when do this.

Start by backing that die out all the way, then raise the ram and turn the die back in until it touches the shell holder. Then turn it back out about an eighth of a turn.

Size one fired case, then wipe the lube off and see how it feels when you chamber it in your rifle. If it's tight (and I can tell you it WILL be), turn your die back in a little more and repeat.

Be aware that turning the die in just 5 degrees will change the shoulder set back by 0.001 inch. Five degrees is a tad bit less than how far the second hand on a clock moves in one tick.

Keep turning the die in just a bit at a time. You're looking for that point where you perceive that the bolt is closing a little easier, which means perfect fit. Once you find that point, snug down that lock ring on your sizer and leave it there. If you want to measure the shoulder on a case that fits the chamber perfectly for future reference, then do so.

Setting up the die based strictly on measurements and disregarding the "feel" aspect will work , but you may be leaving some available precision on the table.

Thank you gentlemen

Do yourself a favor and buy a Hornady Headspace Guage, which will eliminate the guesswork.

http://www.midwayusa.com/product/479704/...with-comparator