Hornady match dies- technical question

[Col. Harrumph]

These die sets are different... in addition to the dies, you need a neck sizer bushing, sold separately. These are available in 0.002" steps. So for a .264 bullet, you can get them in .260, .262, .264, .266". The die instructions say:

"Measure the outside diameter of your loaded cartridge. Subtract .002" to .003" from the neck diameter to determine bushing size. This allows for brass spring back and a bullet press fit of .001" to .002".

I get this much of the above: the inside neck diameter of the sized case should be .001-.002" smaller than the bullet diameter. What I don't get is, why the range of options? The available bushings span a range of .006". Is there that much difference in case neck outside diameter among the various brands of brass?

 

[Demi-human]

Yes. Differences of neck wall thickness, as well as differences of neck tension with the bullet diameter that you are using. I would predicate this with the fact that I am still an amateur. However this is how I have understood it thus far.

 

[Walkalong]

es. Differences of neck wall thickness,

And, for that reasons, one rarely ends up with only one bushing.

 

[murf]

sounds like you are going to have to turn your case necks.

murf

 

[Varminterror]

Yup, if you want to use neck bushings, you really need to be turning for uniform thickness. I turn for uniform batches, take my new case neck thickness (x2), add bullet dia, subtract 2 thou, pick that bushing, and roll tide roll...

 

[RecoilRob]

That is why Lee went the other way by using a mandrel and collet that then crimps the neck inward to contact it. Pretty much accounts for any case neck variability though you still sometimes need to alter the mandrel diameter to get the tension you want. When looking at neck sizing the various bushings and need to neck turn had me go the way of Lee.

 

[ironworkerwill]

Like varminterror says and you should end up with one bushing. Not turning cases and you have a bunch and be chasing your tail.

 

[Walkalong]

Even neck turning you'll want to experiment with a couple sizes or so.

 

[Varminterror]

I generally buy 3-4 bushings for a given set of brass. The size I'm expecting to use, one looser, and one or two tighter. 90% of the time, I end up only using the one I intend to use, and 100% of the time, once I figure out which bushing the bullet likes best, I only use one ever again. Depends on the bullet and the brass mostly, so I test to see which gives the best chamber fit and least bullet distortion to produce the highest precision.