Full lenght bushing die

[FilippoMo]

Hello,
I am using a full length bushing die to load for my 308.
The rifle has standard chamber and fired cases necks measure .342.
My bushing is 334 with neck thickness .14.Even with the best cases that have a runout of .001 (measured with a neco gauge)
I still get unacceptable runout in some rounds.
My question is :would an intermediate bushing (for instance .338) be beneficial when one has to reduce neck size that much?
Any comment appreciated
sincerely
Filippo

 

[uncleduke]

In short; yes, size down in steps. Forum member German Salazar's web site (The Riflemans Journal ) has a wealth of info for reloading procedures.

 

[hogan]

Think your bushing is way too small. Try a .336

Might also try depriming without the sizing button installed.


Another tip is to adjust your sizing die for concentricity with your shell holder. Try loosening your sizer's lock ring, (it helps if you are using a Forster type cross-tightening lock ring). Run your depriming rod into the case and remove primer. Before you raise press arm, tighten the die lock ring. This way your depriming rod is centered in the priming pocket and your die is aligned with the shellholder.

Check case after these adjustments. Might also need to clean the die with solvent before making adjustments so you know no foreign matter was influencing your results.

 

[FilippoMo]

Think your bushing is way too small. Try a .336

Might also try depriming without the sizing button installed.


Another tip is to adjust your sizing die for concentricity with your shell holder. Try loosening your sizer's lock ring, (it helps if you are using a Forster type cross-tightening lock ring). Run your depriming rod into the case and remove primer. Before you raise press arm, tighten the die lock ring. This way your depriming rod is centered in the priming pocket and your die is aligned with the shellholder.

Check case after these adjustments. Might also need to clean the die with solvent before making adjustments so you know no foreign matter was influencing your results.

I always deprime as a separate operation and do not use my FL sizer.
I use the bushing to adjust neck tension so I do not have an expander in my die (I removed the expander).
I will try your suggestions and thank you for your answer
sincerely
Filippo

 

[BoydAllen]

In your case, given the amount of neck expansion, something like a Forster one piece FL die that has been honed out to the neck diameter that you require, will probably give more consistent results than what you are using. The moderator of this site uses one, with excellent results.

 

[Kenny474]

If you only have .001 run-out after sizing and it increases after seating a bullet, I would look into an issue with the seating operation or possibly inconsistent neck thickness. For example, if your brass is .014 on one side and .013 on the other, the bullet will stretch the thinner side more and seat a bit lopsided. Turning your necks slightly will help this, as you will have consistent neck thickness.

Or try a Lee collet die. They size differently as they squeeze the brass around a collet centered in the case. That way if your necks are not consistent thickness, you will at least have a concentric hole to start with, as any variation will be on the outside.

You also have to consider the accuracy you are getting with the rifle and if it is truly going to benefit from your efforts. Some factory chambers are just so big that the sizing required after firing will never allow for truly perfect brass as it is just worked too much.

But before you go crazy trying to get perfect brass, what brand of brass are you using, what is the rifle, how is it shooting, and why are you worrying about concentricity? Not that concentricity isn't important, but if the rifle is shooting well it may not be worth the bother.

 

[FilippoMo]

First of all let me thank you all for your kind answer.
I will provide more details so you can best judge the problem though I think I have found what is wrong.
All my brass so far is Lapua both small and large primed 308 cases,all cases are neck turned within about .0003".
I resized cases from another rifles with a big oversize chamber with the bushing die and my Wilson full lenght sizer (too bad they dropped this item from production).The body neck alignment in the former is 3-4 thousands while the latter is about .001.
Therefore until I get the bushings to resize in steps I will stick with the Wilson FL and use my neck turner expander to reduce neck tension.
As for accuracy the rifle is a Sako TRG 22 and the best groups so far have been with 155 A max but I do seek a better consistency.
I will keep you posted of my progress if any
sincerely
Filippo