Most people fireform cartridges with a modest charge of smokeless powder that is suitable for normal rifle loads, and inexpensive bullets. However, even when reducing the powder charge to 'starting levels' and using less than premium bullets, this method is expensive, requires a safe shooting area, and unnecessarily wears the bore of the rifle. This method (Fireforming Cases Without Bullets) is inexpensive, easy on your bore, and does not require one to take a trip to the rifle range to fireform brass cases.
BASIC PROCEDURE
Prime your cases with pistol primers to keep pressures reasonable. Do not use rifle primers.
Use a small charge of Bullseye or similarly fast burning pistol or shotgun powder. How much? OK, according to the late George Nonte, "Ten grains of Bullseye will do a good job of forming the .219 Zipper Improved cases. Sixteen grains of the same powder does an equally good job in blowing out standard .30-06 cases to size and shape for the .35 Whelen Improved ... start with a small charge of Bullseye that will fill about ten percent of the volume of the unformed case. Work up from this until a charge is reached that gives a cleanly formed case. Watch the primers closely for any signs of excessive pressures. It is entirely possible to develop a dangerous pressure with this type of load. Half grain increases are plenty until adequate expansion is achieved."
An easy way to calculate the "10 % starting load" is to completely fill an empty, unformed case with a spent primer in place with Bullseye powder. Pour out the powder onto your powder scale, and weigh it. Divide this weight by 10, and you've got it.
Take a quarter of a sheet of toilet paper, wad it up, and gently tamp it onto the powder.
Fill the case up to the mouth with a cheap, granular, non-abrasive, inert filler. Any of the following work fine : Instant Ralston, Cream of Wheat, cornmeal. Don't use anything so fine which may 'pack' into a block, like flour. Make sure it is granular.
To keep the filler from spilling out, press a small blob of bullet lubricant over the mouth of the case.
Make sure you're in an area where noise or discharge of a firearm is not a problem. Even though this method is claimed to be very safe, you don't need to make problems for yourself with your neighbor or local authorities. Insert each cartridge into the chamber by hand, point the muzzle upward, and fire.
Check the case. If the starter load is too weak to fire-form the case all the way out against the chamber wall, load another case with a slightly larger powder charge - no more than 0.5 (one-half) grain more - and try it if the starter load gives no signs of dangerously high pressures.
I hope this write-up proves useful to you. Good shooting from the Spirit of
'76 Gun Page!!
