Mike,
For the reamer you are looking at getting, a couple of additional things to thinks about.
OAL length, you can specify a length which will determine you trim length.
As brass is fireformed and come out at approximately 1.495" you will want to get a neck
length that gives you a safety margin as well as less case trimming.
I have had them as short as 1.507" which means you have to pay attention to your case length, and trim
on a regular bases.
I now use a OAL of 1.525" as this enables the brass to grow somewhat normally, leaving .010" to .015"
safety margin considering this is where the carbon ring will be.
My first gunsmith used a 1.535" OAL which definitely gave him a safety margin with a beginner shooters
like myself.
The next area is the freebore for the reamer, the past norm was .060" as most folks were using 6 to 8 ogive
flat base bullets made on .825" jackets.
As this changed with the new double ogive bullets and or BT's. Now you will see reamers running at .000" to .060"
based on bullet selection. For the Bart"s, Bruno's, Hottenstein's which are double ogive bullets, .000" to .030"
would be the way to go. For the more traditional bullet style, I would look at .030" to .050" freebore.
Another factor that comes into play is jacket length, a lot more bullets are being produced on .790" length jackets.
This whole issue is about the bullet being gripped in the neck and being able to reach the lands/rifling.
As you are planning on buying a new sizing die this part is not so critical, but if you had a good sizing die, you
could have your reamer cut to enable you continuing to use it. I wonder how many reamer variations are based
on this detail?
If you are using FB bullets I would concider going with a .040" freebore on the reamer, this will push the bullet in the neck
a little more but may still let you get double ogive bullets out to the lands with some neck grip left. If it is a boat tail you
may have to ensure it is on the .825" jacket length.
DanO