Elmer Keith developed the .44 Magnum in .44 Special cases in beefy .44 Special revolvers. The only reason the .44 Magnum case is longer than .44 Special case is to prevent the warmer magnum loads from being loaded into a light .44 Special revolver by mistake and destroying the gun.
When you look at the SAAMI spec for .44 Special, the maximum length is 1.615". For .44 Magnum it is 1.610". Virtually the same. That means, when you put the same bullet in either case and seat it to the maximum COL for either cartridge, you have virtually the same amount of powder space underneath. That means the same loads will reach about the same pressures in either case. Your .44 Special load will behave about the same whether you load it in the long case or the short one, as long as you use the same COL for both.
If you seat the bullet to a longer COL in the magnum case, as when aligning a crimp groove with the case mouth, then the pressure in the bigger case will be a little lower because the space the powder starts burning in is is now bigger and needs more gas to reach a given pressure. To get the same velocity for a 240 grain lead bullet seated out longer by the amount of the greater length of the magnum case, you will need about 7% more Unique powder.
The minimum load listed for the magnum case is just a suggested starting load for the higher pressure magnum load capability. It is not a minimum pressure requirement or the .44 Specials couldn't be fired in it.
Note that to shoot lead bullets well and with limited leading, the gun's condition is a lot more critical than for jacketed bullets. You need the chamber throats to all be uniform diameter and at least half a thousandth bigger than the groove diameter of the bore. The bore should be smooth and free of constrictions. It is common in revolvers to have a constriction where the barrel thread screws into the frame, and it requires lapping or firelapping to clear it out. If you are getting leading that is especially thick just beyond the throat in the bore, this could be a problem you have. Slugging the bore and chambers will tell you all the needed information (search the forum on slugging bores).
Short of gunsmithing, there are two things you can try to reduce leading. One is to add lube to the bullets in the form of Lee Tumble Lube. Thin it with about 10% mineral spirits and otherwise use as directed. The idea is to get a little extra lube over top of what is already there.
The other thing you can do is use wads at the bullet bases. A simple cardboard wad can be stuck to the base with the additional lube I just recommended. You can also cut out wads from 1/16" polyethylene using a sharpened case. That stops leading pretty well even without added lube if you seat the wads in the case mouths just before seating the bullets. Note that wads can fly off and hit things on the way to the target, so you don't want to use them if you are taking chronograph measurements, as it puts your chronograph at risk.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Last edited by Unclenick; July 26, 2011 at 10:19 AM.
Reason: corrected typo of 3/16 to 1/16
|