bushing neck sizing die?

[lurcher]

Has anyone tried this die?

obviously you would probably need to neck turn first as with all bushing neck sizers
Being a one size fits all die just wondered if there were likely to be issues with concentricity? compared to a redding s-type or wilson bushing neck die?

Also if you are using a bushing neck sizer I understand that all the imperfections in neck wall thickness are pushed to the inner surface. If you run a mandrel (KandM or sinclair) through afterwards would this push them back to the outside?

 

[BountyHunter]

obviously you would probably need to neck turn first as with all bushing neck sizers

Big time wrong assumption!

You would not have to neck turn, depending on the size of your chamber neck. ie unless it is a tight neck chamber. Absolutely not needed for factory chamber!!!!!

You are simply adjusting the amount of tension put on the bullet compared to the neck thickness. Instead of say .008 neck tension you are using different bushings to give say .003, which is probably a good number to have in a magnum magazine load.

A standard die is going to squeeze the bullet/case neck down to a certain size regardless of the neck thickness of the case.

A bushing die allows you to change bushings and maintain a standard neck tension squeeze.

Yes, the imperfections are pushed to the inside, but unless you have wide variations in neck thickness on a case, you will not be able to normally tell it in group size in a factory chamber. You have to remember the difference between a factory chamber (sloppy all around and nothing you do to the case will change that with a factory die) and a tight neck min SAAMI (minimal gap between loaded round and chamber walls and neck).

Now if you run the expanding mandrel back in you will push the imperfections to a minor degree back out. However, any mandrel sized to do that and you will not have neck tension on the bullet, so back where you started from with basically an unsized neck.

IMO too much effort is being spent on neck turning in factory chambers and barrels when you will not routinely show a 10% decrease in group size. Bigger decreases will be shown in load development with powder, primer and seating depth adjustments.

Concentricity has nothing to do with being a non neck bushing or neck bushing die. It simply has to do with the quality alignment of the reaming of that particular die and its alignment with your press and shellholder.

BH

 

[boomtube]

"If you run a mandrel (KandM or sinclair) through afterwards would this push them back to the outside?"

Yes. Your idea is good but those two may be a tad too large. Use a Lyman "M" expander die instead, it's made for that kind of work and does it well.

Perhaps the biggest problem causing run-out is a too tight neck. More than 1, or at the most, 2 thou requires excessive seating force. The bullets will tilt and start entry at an angle. No attempt to correct it by seating part way and turning it to finish will make much difference, once it's started a bullet will usually continue on at the ange it started.

I use and recommend the Lee Collet Neck Die for best, easiest neck sizing for factory chambers. It makes the neck ID pretty much the same, and the right diameter too, no matter any neck thickness variations. But, it's different to use and has a learning curve, those unwilling to make the effort to learn to use it should stick with conventional neck dies.