Weekly Gear Update – Forster Honed Dies

In this 6.5 Guys Gear Update, we discuss a service offered by Forster Products to custom hone the neck diameter of their full length sizing dies to customer specifications. For more information go the Forster website at: https://www.forsterproducts.com/

What got us thinking about honed dies was this article. Based on our experience, a honed dies does reduce runout. If you are contemplating a new cartridge and are looking for dies, consider purchasing a honed die right away. There really isn’t a need to purchase a bushing die to determine the correct neck diameter. Instead, measure a loaded cartridge and share that measurement with Forster. They will hone the die .004″ under. This approach assumes the use of and expander ball or mandrel to set final neck tension.

Editor: Ed Mobley (ed@65guys.com)

Copyright 6.5 Guys LLC


Latest Comments
  1. Gary Shaw

    In your discussion about mandrel in lieu of expander balls, I recall you suggested (for 6.5) using a .086″ neck bushing before using the sinclair neck turning mandrel to expand the neck to .289 in advance of seating.

    The Forster honed die process mentioned here seems based on neck sizing at .004″ under the diameter of the loaded round. In the case of 6.5, that works out to .0287 instead of .286 from the mandrel discussion. I’m still new to all this but does the .001 difference between the two matter if the mandrel takes it back out to .0289″ anyway?
    Thanks again for all you do for this sport( obscession?)

    • 65guys

      Hi – the .001″ really doesn’t make a different so long as you are expanding to the final neck diameter.

  2. NMLR

    Are you using the expander ball in your honed dies ?

    • 65guys

      We’re currently using a Sinclair mandrel. However, there is nothing wrong with using the Forster expander ball. They will even customize the expander balls if you want a particular neck tension.

  3. NMLR

    How much neck tension do you typically look for ? How would you go a little selecting / sizing an expander mandrel ?

    What process do you use to determine neck bushing size also ??

    Thank you in advance

    • 65guys

      We shoot for .002″ neck tension. The Sinclair carbide mandrel in the caliber of your choice will accomplish that. While we’ve moved to Forster honed sizing dies, if you only want to purchase one bushing that you know will work, measure the neck diameter of a loaded round and subtract .004″. Then use a mandrel or expander ball to set your final neck tension. Same goes for purchasing a honed Forster sizing die: Tell them what the neck diameter of a loaded round is and they will subtract .004″ and hone the die accordingly.

  4. Marty

    Thanks for the interesting blogs and videos!

    What size did you go for with your 6.5×47 Lapua and 308 Win?

    • 65guys


      Using Lapua brass for both cartridges, our dies were honed as follows:

      .308 – .334
      6.5×47 – .286

      You’ll still want to use an expander ball or mandrel to set the final neck tension.

      Thanks for watching!

      • Marty

        Thanks for replying, however there is something I don’t fully understand.
        Forster customer service told me that the “factory default” neck diameter of their full length sizing dies are:
        .308 Win. – .335
        6.5×47 Lapua – .284

        Increasing the neck diameter (decreasing tension) for the 6.5×47 Lapua I fully understand, going from .284 to .286 is easy.
        But decreasing the neck diameter and increasing tensions with the .308 Win. from .335 to .334 seems impossible to me.

        What happened with the .308 Win. die?

  5. Craig Menke

    I am just getting into this game and though I have been reloading on and off for years I am a little confused. You mention in several of your videos and articles that we should measure a loaded cartridge to get our outside neck measurements to order a honed die, but this doesn’t seem like an apples to apples measurement. What I am trying to say is that if we load a cartridge with another die then the neck tension and everything will be based off of that die. To me this means that we aren’t taking into consideration case thickness. Would it be more accurate or even feasible to measure the components that make up loaded cartridge at the neck (bullet & case neck wall thickness) then subtract the .004″ to order the honed die? I guess my point is that you mention about not buying multiple dies and going with what you have, but if we are just starting out in a caliber and want to go with a honed die with your steps we are forced to buy multiple dies or to buy a Forester die, load with it and then ship it back to be honed. Maybe I am thinking about this wrong (I hope I am), but it doesn’t add up to me right now.

    • 65guys

      Hi Craig,

      When you hone a die, you are making a commitment to a particular manufacturer of brass. If you plan to use multiple manufacturers of brass for a particular cartridge, it’s best to leave the die alone as the expander ball will set your neck tension.

      You could measure all of the components as you describe, but unless you have a tube micrometer your measurement of neck thickness will be off.

      Let’s take the example of the new 6×47 Lapua dies we just got. While Steve has decided to go with a Redding bushing die, I went with the Forster sizing die as I plan to get it honed out. Here’s what I’m going to do:

      1) I’m going to take the factory die and size some 6.5×47 brass to neck it down to 6mm. I’ll either use the factory expander ball or a Sinclair mandrel to set the neck tension
      2) I’ll seat a bullet with the sizing die. Bullets for a particular caliber are going to be so close in diameter irrespective of the manufacturer, you’d need a caliper that measures out to .0001 to tell the difference so it’s not worth worrying about.
      3) I take the loaded round and measure the outside neck diameter. I take that diameter and subtract .004″. Why .004″? Because it’s enough sizing to account for variances in brass neck thickness, bullet diameter and any errors in measurement but not so much that the brass is oversized as is the case with a standard die.
      4) I send my die to Forster with this information and get it honed.
      5) I take my new honed die and size my brass. Since the brass is still going to be slightly oversized by a thou or two, I still set the final neck tension with an expander ball or mandrel.

      I’m sure there are different ways of doing this – this is just the way that works for us.

      Thanks for your questions…

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