Reducing Run-out with Standard FL Sizing & Seating Dies

[jaboomgaarden]

The articles below explained how to reduce runout using standard FL sizing and seating dies.



http://bulletin.accurateshooter.com...ase-concentricity-with-standard-seating-dies/

Have any of you tried this? If so, what were your results? Better, same, worse? These articles published some data showing it can be done to the same effect of redding fl busing dies and competition seating dies.

I reload for a 308 gas gun. I'm trying to narrow down the most important steps that gain you the most consistency. The research i've done mainly points to concentricity being a key factor. I'd like to attempt this before spending $175 on a redding competition die set.

 

[jaboomgaarden]

I found powermac's response in an older forum...

"
If your rifle is performing as good as you can shoot, obsessing about runout might not be very beneficial. Shooting at longer ranges small variances shows much easier downrange.

One thing you absolutely should try if you have a press with standard threaded die holder, is getting a appropriate size O-ring and put between the die lock ring and the press, it will help the die and case self align as it induces a little play, as a o ring costs nothing it certainly a trick worth trying.

And if you have not tried already, size the case, back the ram out enough to spin the case 180 degrees and size again, both of these tricks can improve your concentricity, and are cheap.

The Redding FL dies and the Forster Br seater die is both of good quality, and should normally not give you much runout, the expander ball might be one of your issues as it does'nt do any good for your concentricity.
If you want to look further the collet die would be the logical choice with what equipment you have. You will not be able to adjust/control neck tension, but without turning and expanding necks, the returns from it are questionable. As Neck thickness is not constant neither will your neck tension be.
And at 300 yards witch is your maximum range the increase in ES/SD will most likely not show.
"
http://www.snipershide.com/shooting/threads/reducing-bullet-runout.208956/

He seems to think its a good idea. The goal for rifle is 1200 meters, so i think this is necessary.

 

[Greg Langelius *]

Runout and concentricity are some things I used to obsess about when I was getting into serious precision shooting and handloading for it. It suddenly became a lot simpler when I learned a few key things about rifle barrels, rifle chambers, and the ammunition requirements for them.

Because I started later in life than many at this, I made an arbitrary decision to only own SAAMI chambers. The reasoning was that I had offspring (and she had offspring not long after I started into this), and the rifles I owned were going to end up in their hands someday. If I passed on rifles that required caution when shooting off the shelf ammunition, I'd be effectively putting danger into my Daughter's and Grandchildrens' hands; and I was never going to allow anything like that to pass.

Well, SAAMI chambers have larger tolerances which largely negate refinements in cartridge concentricity and runout. I would simply set up my die by bringing a case to full stroke, then loosening and retightening the die lock ring. This process allows the die and press, with the case fully engaged, to find a minimal stress relationship. If any kind of misalignments existed before, they at least had a chance to find a 'happier relationship".

Also, my mentor told me to do it, so...

One other thing I do is to back off the F/L die a turn or two, leaving some of the lower part of the case neck unresized. IMHO, this could engage that portion of the neck into a mild interference fit within the chamber neck; thus (hopefully) centering the forward portion of the cartridge more fully within the chamber.

One thing I've noticed is that carbon/blow-by staining on fired cases stops abruptly at the demarcation between the resized and unresized portion of the neck. One might expect that some sort of shoulder bump would eventually become an obvious need, but it has yet to become obvious at all. I suspect that my aversion to hotter loads may be in some way alleviating such a need.

This is my only set of concessions to concentricity and runout. For all I know, they may be pointless; but it eases my mind to at least believe that I am in some manner addressing those issues.

Now some of you are newer here, and may not be aware that I am a bit of an agnostic when it comes to diving deeply down into the rabbit hole of handloading complexities. I keep my handloading process as basic and simple, and consistent, as possible. My one concession to anal reloading mantras is to weigh each charge; but I also have an automated powder measure to do this for me.

Greg

 

[padom]

Get yourself a Forster FL sizing die for $36.99. I've tested them all. The Forster FL sizing die setup to bump shoulders .003 for a semi produced top quality ammo with some of the least runout of any other sizing die out there with their high expander ball.