View Full Version : 300 RUM Dies

06-11-2008, 02:52 PM
What is the best way to go for 300 rum reloading dies. I just baught a RCBS 2 die set but it sounds like ther are better dies out ther for neck sizing and concentricity between the neck and the case body.
Any suggestions?

06-11-2008, 07:21 PM
Are we talking Hunting rig or Match rifle for long range.

If you are loading for a hunting rifle the RCBS will be fine. It will be difficult at best to affect the accuracy of your hunting rig by much with different dies.

One of my hunting rifles is a 300 Win Mag on a Mod 70, used RCBS dies for years. Got a wild hair to spend $150.00 on a set of Reddings, still shoots the same.

If it is a long range target rig with a tight chamber, talk to the smith that built it for his advice on dies that are best suited for your chamber.



06-11-2008, 07:40 PM
I will be hunting long range and some LR target . I have had some experience with runout problems in loaded ammo and would like to eliminate this. I am just not sure what type of die set I would need to accomplish this. I hear a lot about Redding but I am a little confused on what die set I would need. RCBS has thier match dies also . bottom line is I want the finished round to be dimentionaly accurate. .
I am shooting a 700 sendero in 300 rum .

06-12-2008, 05:04 PM
There are alot of things that can cause your run out issues, so look at everything before you drop the change for new dies.

What kind of concentricity gauge are you using to determine the run out. And how much are you considering too much?

Is the run out on the bullet or the neck?

Did you check the run out on a new piece of brass before sizing, after sizing, after firing, then after sizing again?

Please do not take me wrong, it may well be your dies, but with the quality that is coming out of the factories today, your problem could be in the chamber also.

Here is what I have done in the past.

Take 5 virgin pices of brass (do not use fired brass), Number them with a Sharpie, check the run out on the neck and the body just below the shoulder. Make a note of the results.

Now FL size them, check again, if you get more run out, you have fround the problem. Sometimes, just a die adjustment can cure it. If you have your die bumping the shoulder too much, it can actually bow the case into a banana. Not the dies fault.

You can also check to see if the expander ball is causing the problem by removing it from the die, size the case and check the neck again.

If the run out is the same or better after FL, load them, check bullet and neck concentricity and note it down for each piece of brass. Head for the range.

After firing, start the above over. If you develope run out in the case after it has been fired, it ain't the dies. And buying a better set of dies is not going to cure the problem.

Regarding dies, I refuse to use anything today that has a expander ball in it. All my dies use or have been converted to a bushing style die. When sizing a neck with a standard die, then pulling an expander ball back thru the neck to expand does alot of harm. Work hardens the brass, can bend the neck, etc.

So, if the problem is the die, purchase a set of REDDING "S" dies. You don't need the fancy Comp Seater, waist of money for most rifles. Redding can help you determine what size bushing you need, or post the question here and one of us will explain how to determine the best bushing size.

Hope that was not too confusing?

Again, I stress, use new virgin brass, don't bother with this test with once fired brass. Fired brass can have a mind of its own and you could end up chasing your tail.