I tried using the Mag Tech cases early on when I was trying to develop my .600 Nitro Special. The problems I ran into were that the Mag Techh cases are set up with small primer pockets and those don't put out enough fire to get the powder in the large cases started properly. There is enough metal around the pocket to ream it out to the large size primers and also to deepen it enough so that they can be mounted flush, which I did in order to get more starting power.

That helped some, but the results still weren't satisfactory. I feel that the other problem is that the case is so thin walled at the mouth that I wasn't getting enough neck tension or standing inertia even with a 650 grain bullet, to get the powder started well before the bullet started moving forward. This is due to the poor neck tension, mainly, and possibly made worse by my powder choices, as I was trying to use some of the slower burning powders. Even after going up to medium burn rate powders, I was still having ignition problems.

In some cases the primer would go off, leaving a mass of charred powder still in the case and/or the barrels, but would push the bullet clear down the barrel and make a very strange bloop noise. This blooper business would push the bullets clear out of the barrels but you could almost see them rolling along the ground. In a couple cases the bullets only went down the barrels a foot or so. I determined that if this should happen, and then the remaining powder should then go off, I would be left holding a bomb in my hands.

I had to do something else so I ordered some turned solid brass three inch cases with 209 shotgun primer pockets in them from Rocky Mountain Cartridges. They told me over the phone that others had had the same ignition problems and that the best solution was to go to hot 209 primers. They not only put out more ignition fire, but it also lasts longer to get the whole powder charge ignited. I had them mark these cases ".600 Nitro Special" so that someone wouldn't decide to shoot one in a 3 inch 20 gauge at some time in the future. That could be catastrophic!

These cases will be used in a specially made gun, based on a 10 gauge magnum, crossbolt action with .620" bore rifled barrels turned to a .600 N.E. profile. The size .620 bullets weighing 650 grains each, are made up out of medium hard lead and will be driven to approximately 1850 FPS. (I had already achieved this speed using the Mag Tech cases, but they were just too undependable for this use.) Trying to use Mag Tech cases for loading heavy weight bullets is like playing Russian Roulette with your life, and is definitely not worth the risk! Don't do it!
Bob