Well me and BJ just got a SInclair concentricity gauge and their new neck turner. I just ran about 30 of my 25-06 handloads under the gauge and only 4 had less than .003 in runout. Most were around .006.
How do I remedy this problem, I am currently using RCBS and Hornady dies
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A search for either “runout” or “concentricity” will get you a ton of reading.
One thing you can do is take a case before you do anything to it as far as prep goes and measure everything before and after each individual step and this will probably tell you which step in your case prep process is causing the problem.
With the standard type dies there is always the possibility you may not do better but you can try a lot of things. A lot of problems are caused by standard full length resizing dies. Play with the decapping rod and expander ball to see if you can adjust it slightly up or down and get the unit centered better and possibly decrease runout. Depending on your chamber neck dimensions and your case dimensions you might be able to eliminate the expander ball. The expander ball being pulled through the neck is one of the biggest culprits when it comes to neck runout.
Make sure all cases are the same length, squared exactly, and that all are deburred and chamfered the same.
It sounds like, by your description, you are talking about case neck runout before you even get to the seating process. Also, is you measurement before or after you turned the necks? The first thing I’d do is take about 5 or 6 cases as a test group and run them through each of your steps and measure every thing before and after. Find the step that is causing the problem and deal with that step to make it as good as you can. You may end up going with Redding comp dies, or something similar, if you can’t get yours to give you what you want but you should be able to at least determine which step is causing the problem and make it as good as you can with what you have.
When you get to the seating process you again need to know that all cases are the same length, squared up exactly, and all deburring and chamfering is consistently the same. If it's bullet runout you're talking about, what was the case neck runout before seating the bullets? You can slightly seat the bullet, turn it a little, seat it some more and even turn it again before finally seating it fully. Sometimes this will give you better seated bullet concentricity. Make sure the seating stem is not interfering with, or hitting, the tip of the bullet. You can play with the seating stem by making slight adjustments to try and center it and get better concentricity when seating.
In the end, the law of averages will probably indicate that you may be better off biting the bullet, so to speak, and going with some quality comp dies. But until you get to that point you can eliminate as much as you can with your standard dies.
I look at the die thing like I would with most everything else in a precision long range setup from gun to reloading. I doubt that you would try to save a few bucks on building your gun but it seems like a lot of people want to save a few bucks and not go with the best dies available. In the end I think you’ll find the money spent on quality, comp dies will be an investment you will be happy with after all is said and done.
Roy.....I waited on you this time [img]/ubbthreads/images/graemlins/grin.gif[/img]
What brass ? Although thats part of the equation you need to get away from the old expander ball .
You don't have to spend a lot of dollars to do this either. Get a Lee collet die for your caliber , use it , you will be amazed ! No lube necessary , runout in the .0005 to .002 range and I have cases that are on their 6th load that are still this way . I use a neco gauge , 3sixbits thought well of them and Abinok uses one as well.
For the small $ investment required ( 20 bucks I think ) to find out for yourself there is no reason not to. There are many here that shoot at long range and use the Lee collet dies with great sucess .
I think that the major problem with getting people to try them is the " you get what you pay for " syndrome . I will be the first to admit that I am a subscriber to this school of thought , however there is an additional adage that applies as well. " There are exceptions to every rule" is the one that I thinking about. The Lee dies are " the exception "
A percentage of this (somewhat small) can be caused by neck wall thickness varience. neck turning off the high side helps. A standard seating die can make matters worse. 90% of the problem is in the SIZING process, a standard RCBS or hornady die way oversizes your brass. example: take a fired 270 Win case and measure the neck run it through your RCBS fl die without the expander ball...... .025 smaller check your concentricity guage not bad .001 run out . now put the expander ball back in WOW .001 to .010 run out. this is where bushing dies (redding ,wilson custom come in). minimum sizing on uniform neck thickness brass and treating the expander ball like the mother in law is where the number ZERO is awesome.
It takes 43 muscle's to frown and 17 to smile, but only 3 for proper trigger pull.
"How do I remedy this problem, I am currently using RCBS and Hornady dies."
That's easy. Just put ten of the rounds with .003" and less runout into one paper bag, and stick a folded note in there indicating "low runout."
Then put ten high runout rounds in another paper with a folded note reading "high runout."
Then have a friend mix up the bags and hand them back to you and head to the range--300 yards if possible.
Fire one shot from the first bag at one target, then one shot from the second bag at a second target. Alternate back and forth between bags and targets until all twenty shots have been fired. Allow adequate time for the barrel to cool between all shots.
Observe the targets, paying very close attention to group sizes. Then and only then should you look at the folded notes in the bags. Odds are you won't see enough difference in group size to worry you. But if you do, and it is determined that the high runout is hurting you, then you can begin to take steps to reduce it.