PMA Tool

PMA Micro Die Adjuster w/ Set Screw

(7 reviews) Write a Review


 For as long as we've been reloading we've always hated setting up our full length sizing dies. We've been using shims to help this along for quite a long while now, but have not really been pleased with them. It seems we always misplace them, or can't find the ones we need, or grab the wrong ones, and they always seem to be covered in rust. For as many years as we've been doing this we've always been looking for a better way. After searching off and on for a solution to this nagging problem we finally have a workable solution. The PMA Micro Die Adjuster.


The PMA Tool Micro Die Adjuster (MDA) replaces your existing lock ring and can be used with nearly any 7/8-14 full length sizing die. We successfully used this tool with sizing dies from Redding, RCBS, Hornady, Lee, Harrells Precision and those made from Newlon Precision die blanks. It allows you to easily make adjustments to your “shoulder bump” as fine as .0005”. The engraved marks on the MDA are equal to approximately .001” (true adjustment .000992”) of adjustment to the shoulder bump. Splitting the engraved marks is therefore approximately equal to .0005”. The design of the MDA does not allow it to work with the Forster Co-Ax press and is not intended for use with turret presses, progressive presses or the RCBS Summit press. Some custom dies for very short cartridges may require the use of an extended shellholder.Micro Die Adjuster shown in use installed on Custom Newlon 6mm Grendel Die and RCBS TM RockChucker press.


**Includes Set Screw for locking the adjustment in place

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7 Reviews

  • 4
    Dandy Tool

    Posted by JMatt on 9th Oct 2021

    I ordered 2 of these from PMA and 2 of the Whidden click adjustable ones. The Whidden ones seems to have changed their design very slightly and seem to be less rigid than the original design (in my opinion). For that reason, I have had better luck with these PMA rings. I thing there are a few things that could improve the rigidity of these too, but at the cost of bulk and a significant increase to machining complexity. Also, I never have been a fan of smashing a small lead shot against threads for grip. These PMA rings do this, but it still works better than the Whidden design (with the ones I have anyway). Overall, these are a quality product that I am very happy with. They are easy to set up and use, and I may end up buying some more very soon for my other sizing and bumping dies.

  • 5
    Works great

    Posted by Brett Brown on 12th Jun 2021

    I have always sized with a Forster. I bought a Harrell's press just to use it with this adjuster. It seams every time I took a die in and out of the Forster, it would be off a .001". (plus as the brass hardens it has less spring back and needs adjustment.) I liked it so much, I purchased a second one. I prefer the allen screw

  • 5
    EZ PZ

    Posted by Unknown on 20th Jul 2017

    Makes setting the die EZ PZ

  • 5
    fine adjustment for ram priming die

    Posted by John on 4th Apr 2017

    The fine adjustment of my ram priming die is accurately repeatable with the micro die adjustment tool. An excellent capability when switching cases or primers.

  • 5
    Dial-A-Depth: Best Back-bumper

    Posted by Gary on 15th Nov 2016

    This is truly simple to install and use. Further, there's less tool-pieces to install/remove when changing dies. I've been the route the makers speak of and while there's another method that works well this tool is easier to use all-around.

  • 5
    PMA Die Adjuster

    Posted by Ron on 26th Apr 2016

    For me using shims etc. to adjust bump was a pain. PMA's die adjuster is like their other reloading products a nice quality tool that works well.

  • 5
    Don't know b/c I am deployed

    Posted by Kirk on 12th Apr 2016

    I am almost half way done with my deployment when I saw this product. I figured it will be waiting on me when I get home. Looks like it shall do the trick allowing me to make finite adjustments to my shoulder bump.

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