Oh boy!!! Here we go.  Without a doubt, my favorite all around varmint cartridge is the 6mm Ackley Improved.  While 6mm brass at times can be difficult to find, if you are willing to do a little work forming your own, you can have high-quality brass that will last through many more firings than Remington or Winchester 6mm brass.

Norma 7×57, the 6mm Remingtons parent cartridge, is more readily available from online suppliers than 6mm is.  A quick google search lists brass available from Midway and Bullets.com.  Links are below:

Midway USA:  Norma 7×57 Mauser Brass

Bullets.com:  Norma 7×57 Mauser Brass

We here at Taylor Accuracy will also be carrying the Norma 7×57 Mauser brass before the end of 2017.  Also, full case forming and prep services will be offered.

Here is a list of the items you will need to properly, and reliably form 6mm Remington brass from Norma 7×57 Mauser.

  • Reloading Press (examples)
    • Forster Co-Ax
    • Redding Boss
    • RCBS Rockchucker
  • Case Lube
    • Lanolin
    • Hornady One Shot
    • Imperial Sizing Die Wax
  • Full-Length Sizing Dies
    • 257 Roberts Die
    • 6mm Remington Die
    • 6mm Ackley Improved Die – For Use After Fire Forming
  • 6mm Ackley Improved Body Die
    • You may need to shave .030″ off the base of this die so you can properly bump necks.  This will depend on the chamber used in the rifle.
  • Neck Turning Tools (If needed)
    • Neilson Pumpkin
    • PMA Turning Tool
    • 21st Century Turning Lathe or Tools
    • You will need 40-Degree cutters on the tools if turning after fire forming
    • If you are turning necks before fireforming you will need 28-Degree Cutters
  • Neck Expander Mandrel and Die

Here are the steps to forming the brass.  A youtube video will be available before the end of 2017.  We typically start making 6mm AI brass for sale in the week after Christmas.

Steps to form 6mm AI from Norma 7×57 Brass:

  • Note – Always use lube before each pass through a full length die!!! If you stick one you’ll hate your life. Also, I will describe two ways to form brass.

Method 1 – The Wax Plug Method

  1. Lube cases
  2. Run virgin Norma 7×57 Brass through 257 Roberts full length die. Pay attention to only form until you press the new 257 neck into the shoulder.
  3. Lube cases
  4. Run newly formed 257 Roberts cases through 6mm Remington full length die. Again, only until you form the neck to the neck should junction.
  5. Turn necks to .0005-.001 under your chambered neck diameter
    1. If your chamber is .274 neck, then turn to .2735 or .273
  6. WARNING THE NEXT STEPS MUST BE TAKEN CAREFULLY!!!!  Taylor Accuracy is not liable for any issues you have with this method as we do not know your weapon.  You assume full responsibility for any and all reloading situations.
  7. Use Bullseye to fireform your brass
    1. Start with 60% of case capacity of bullseye and load
    2. Plug case neck with beeswax
    3. Lube the cases with 5W-20 Motor oil or other lightweight oil
    4. Fire
    5. If the neck comes out square to slightly rounded with no bubbles – you’re good. If the shoulders are very round then you need more powder.
    6. Up to 65% and fire again.
    7. Continue upping the percentage until your shoulders look good.
    8. GO SLOW – THIS POWDER RAMPS UP VERY FAST!!!
  8. Now you have completely formed and ready to go brass.
  9. Turn necks down to .003 clearance of your chamber.  This would be .271 in a .274 chamber.
  10. Cut slightly into the shoulder with your turning tool so that a donut does not form
    1. This slight cut might be more significant if you do a full neck turn with shoulder cut before fire forming as cases are not always straight.

Method 2 – Fireform With A Loaded Round

  1. Lube cases
  2. Run virgin Norma 7×57 Brass through 257 Roberts full length die. Pay attention to only form until you press the new 257 neck into the shoulder.
  3. Lube cases
  4. Run newly formed 257 Roberts cases through 6mm Remington full length die. Again, only until you form the neck to the neck should junction.
  5. Turn necks to .002-.004 under your chambered neck diameter
  6. Load a traditional 6mm Remington charge and seat a bullet of your choice.
    1. Ensure the bullet is jammed hard into the lands to prevent false head spacing
    2. This will also ensure full forming of the brass.
  7. Lube the cases with 5W-20 or other lightweight oil.
  8. Go hunting

 

Method 1 will form your brass without losing barrel life.  However, you might need a few more firings of the Bullseye until you get your powder charge down for your brass lot.

Method 2 is typically more fun as you can go varmint hunting as you fireform.  However, be sure to follow 6mm Remington loads until your brass is formed.  This method will also burn up some barrel life as you are actually firing bullets.