Help Requested: Not pushing shoulder back.

[Dinky]

My friends,

Well, I have progressed (painstakingly, to be sure I know what I am doing) to the point of resizing cases for the 300 Win. Mag. Here are the facts:

1. Remington cases, once fired--right at maximum case length but still OK--primer pockets uniformed and flash holes deburred.

2. Cases were fired in my bolt action and when I take a reading in the RCBS Precision Mic, they show a relative reading of +1. I take this, within a thousandth or so, of the same dimension in my rifle.

3. So, to be safe, I decide to push the shoulder back so that a reading on the case will be - .002.

4. I set up the RCBS resizing die by running it down until contact is made with the shell holder. I then turn the die down by eighth to quarter turns. Early on, the case is deprimed, as expected, and the neck-sizer ball slides through fine. As I keep turning the die down, eventually, I feel the case resize.

5. But a measurement in the RCBS Mic shows the shoulder in exactly the same place. I turned the die down finally, FIVE FULL TURNS and still see no pushback of the shoulder whatsoever.

I am almost certain I am committing some really boneheaded error, but I think I followed instructions to the letter. Any ideas?

(Editing to add that I told my wife I had run into some problems with my reloading and would need to leave my equipment on the table and my press stand out of the closet until I checked what was wrong with the forum. Her response was: "Is it going to explode?"

Thanks very much.

 

[Edd]

I don't understand step #4. If you set the die up to contact the shell holder, how were you able to keep turning it down?

 

[Dinky]

Edd: pushed arm back up, then screwed down the die.

I am wondering if it was caused by the wrong shell holder. I used RCBS # 38. That is listed for the 300 RUM but not for the Win Mag. But I thought they used the same holder. I will check this when I get home.

 

[wyowinchester]

I could be wrong but.
If you are in contact with the shell holder with the die. The shell can not go into the die any farther, no matter how far you screw the die down. The press just doesn't go to full stroke.

 

[7magcreedmoor]

I also am puzzled as to how you are able to keep turning the die down after the initial set-up. Having said that, if you set up the dies according to the manufacturer's instructions (which should say something along like "run the ram up all the way, screw the die in until it touches the shellholder, lower the ram and then turn the die down approximately 1/8 to 1/4 turn more, so that you feel a slight 'camming' effect as the press lever bottoms out") you cannot get any more set-back of the shoulder without switching to a custom shellholder. If your before and after headspace measurement is the same, you don't really want any more anyway. With a bolt-action, you have enough cam-action when chambering a round to overcome any slight resistance from the little case-to-case variations you'll see. It sounds like your rifle is headspaced right at the minimum and matches your FL die perfectly. A more common situation is the measurement of the case fresh out of the rifle is a few thousandths longer than that produced by the die. Most of my rifles fall into this category. I use Redding Competition shellholder sets to match my FL die output to the fired dimension as closely as possible, at most +.002". Accuracy is generally better, and brass lasts longer the less you move the shoulder back and forth.

 

[MagnumManiac]

Firstly, use the correct shell holder, RCBS #4 is for the 300WinMag.
Secondly, it sounds like you have a minimum chamber if your mic is reading +.001" of your fired brass. I would suggest you go and buy a RCBS 300WM Neck die and use that to size your necks. You may find it takes several firings before cases get tight to chamber.

If you want to use your FL die, get yourself a set of feeler guages and place a .005" shim/guage under the case and on top of the shell holder, size a case and check it in your mic, you may need to go as much as .010", I go up in .001" increments until the shoulder is moved the desired amount.
Or get .010" machined off the TOP of a shell holder and adjust your die as you described until you get .002" bump on your shoulders. I do this with a new shell holder, they're cheap, and I keep it with those dies for the life of that rifle.
I've run into this a few times myself, my custom 375 Weatherby is right on minimum dimension and my Redding dies WILL NOT bump the shoulder at all, had to turn .010" off a shell holder to get the shoulders bumped for easy chambering.
This isn't common, but it's not that rare to see it in a few factory rifles too.

Please let me know how you go.

Cheers.
gun)

 

[Dinky]

Thanks, guys. I will play with it in a few days and get back to you.

 

[Dinky]

Well folks, everything you said made sense. But you can call off the dogs, and roll up the fire hoses. You could not possibly have figured out what the real problem was--since I have no doubt you assumed that if old Dinky were engaged in reloading, he must have an IQ of at least forty.

WRONG!

Suppose you hired someone to pour wax into a round mold and pull out round candles. And suppose further that the poor &*^% kept pulling out square candles. You would think he would check the mold, wouldn't you?

So think of it this way: some poor slob puts his 300 Ultra Mag sizing die away only he switches it with his 300 Win Mag die. He then pulls it out and gleefully starts resizing 300 Win Mag cases in the longer die. No push back. Gee, ya think? The candles come out square instead of round! lightbulb

Yep--guilty as charged. Everything is going quite well with the correct die--although I am having a little trouble getting it to stay set at bumping the shoulder back exactly .003 inches to minus .002. Once in a while, it sets it back a thousandth or two more. Could that be because I didn't lock the lock washer down with the hex wrench?

Also, I am using Imperial wax and it's smooth as silk--but I have to ask, is it normal, with full-length resizing to have concentric rings all up and down the body of the case?

Finally, I have not checked the dimensions of the bottom of the two cases, but I'm thinking I better pitch all the rounds I put through the wrong FL die into the garbage--just to be safe. Any thoughts?

Thanks again for you help, and sorry to have been such a *******.