Rifle - Cartridge - Ballistics - Copyright.
Case - Primer - Powder - Bullet
Load Testing
Calculating Kinetic Energy.
Centerfire Rifle Cartridge Reloading Powder Selection:
 Modern smokeless powder once ignited produce expanding gases that push the bullet down the rifles bore giving us a certain amount of velocity to our bullet.

 Modern smokeless rifle powders have varying burn rates and come in two types, single base nitrocellulous and double base nitrocellulous with the addition of nitroglycerine.

 Modern smokeless rifle powders have various shapes and they are, extruded or tubular, ball or spherical, round flat flake and diamond flat flake.

Rifle Cartridge Powder Reloading:
 There are many rifle cartridge powders to choose from for the avid reloader today each of which vary in their burn rate. With all the powders that are available how does anyone know which powder to select for their particular rifle cartridge reloading.

Load Density:
 Load density is one factor to consider in selecting powder for a particular rifle cartridge with 86% density just about ideal in most cases. Load density is the ratio between case capacity and actual powder charge. Most factory ammunition is loaded with a density of 80% - 90% of the cartridge case capacity.

1. You should try not to exceed 95% load density.
 A. Primers need room to flame through the powder charge which gives uniform velocity and pressure.
 B. Cases that are full or compressed charges of powder will accelerate barrel wear in the rifle barrels throat area and then over time will destroy the accuracy of the rifle.

2. You should never drop to far below 80% load density.
 A known condition named detonation (excess pressure spike) can occur with cases that are not significantly filled with powder. Some years ago the U.S. Ordnance and DuPont ballistics laboratories were able to duplicate the strange phenomenon called detonation and they had determined that excess air space in the cartridge case to be the trigger for detonation.

How to figure load density:
 Powder charge weight divided by case capacity equals load density. Example: Powder charge 40 grains (divided by) Case capacity 50 grains = .8 or 80% load density.

Case Capacity:
 Case capacity is the amount of volume inside a cartridge case that is available for the rifle powder or propellant to fill.

How To Measure Case Capacity:
 Measuring case capacity is actually quite simple. Once you have established your bullet seating depth in the bullet section of this guide.
1. Weigh one case with bullet seated to proper depth without powder or primer.
2. Now fill the case with water through the primer hole using a hyperdermic needle and weigh again.
3. Now subtract dry weight from the water weight and this will give you your case capacity.
  470 grains = water weight with bullet.
- 420 grains = empty weight with bullet.
    50 grain = case capacity.

 Once you have your case capacity using your reloading manual select powders that fall into your load density range.
In the above example of a 50 grain capacity your range would be.
1. 50 grain capacity x 80% load density = 40 grains of powder.
2. 50 grain capacity x 90% load density = 45 grains of powder.

Centerfire Rifle Cartridges:
17 Rem. - 204 Ruger - 22 Hornet - 222 Rem.
223 Rem. - 22-250 Rem. - 220 Swift - 223 WSSM
243 Win. - 6mm Rem. - 243 WSSM - 240 Wby. Mag.
250 Savage - 257 Roberts - 25 WSSM - 25-06 Rem.
257 Wby. Mag. - 6.5 x 55mm - 260 Rem.
6.5mm Rem. Mag. - 264 Win. Mag. - 6.8mm Rem.
270 Win. - 270 WSM - 270 Wby. Mag. - 7mm-08 Rem.
280 Rem. - 7mm Rem. Mag. - 7mm WSM
30-30 Win. - 308 Win. - 30-06 Springfield
300 Win. Mag. - 300 WSM - 300 Wby. Mag.
325 WSM - 338 Win. Mag. - 340 Wby. Mag.
357 Mag. - 44 Mag. - 444 Marlin - 45-70 Government
Powder Measuring And Dispensing Tools:

Resources And References:
Reloading Directoy:
Bullets & Manuals
Powder & Data
Primers & Charts
Rifle Brass For Sale
Rifle Bullets For Sale
Rifle Dies For Sale
Rifling Twist Rates
Rifling Twist Effects
Rifle Barrel Break-In
Rifle Barrel Cryogenics
Rifle Barrel Free-Bore