|Centerfire Rifle Cartridge Reloading Bullet Selection:|
| Rifle bullets have to form a seal with the rifle's bore. If a strong seal is not achieved, expanding gasses from the ignited powder charge leaks past the bullet, thereby reducing efficiency and accuracy. |
The bullet must also engage the rifling without excessively fouling the rifle's bore, and without damaging the bullet, which will also reduce accuracy. The leade angle is the angle cut by a chambering reamer on the very end of the rifling lands. This allows the bullet to begin its engraving into the lands on a relatively gentle angle.
Rifle bullet caliber is the outside diameter of a bullet that fits the maximum inside diameter of a rifles rifled bore in the rifling grooves, expressed in hundredths or thousandths of an inch and typically written as a decimal fraction.
The interaction between rifle bullet and rifled bore are termed as internal ballistics. The action of the bullet once leaving the rifle barrel is usually refered to as external ballistics.
Bullet Sectional Density:
Bullet Ballistic Coefficient:
Rifle Cartridge Bullet Reloading:
While bullet manufacturers are very close today of creating perfect precise bullets the occasional bad bullet can be sorted out. Many reloaders still overlook the reloading value of using scales for their accuracy and ease of use for bullet sorting.
When weighing bullets seperate them in increments of 1/10 of a grain. The reason for doing this is that the bullets components when assembled can create slight air pockets or antimony differences depending on the bullets construction which will change the bullets overall weight.
Bullet Seating Depth:
NOTE; Caution: Do not use this procedure for rifles chambered for weatherby cartridges as these rifles have extremely long throats or free-bore cut into the rifles bore.
Step 1. Insert a bullet into the neck of a unprimed resized case. Do not fully seat the bullet but seat it deep enough that it is gripped fully by the cartridge neck.
Step 2. Using a black magic marker or dykem steel layout blue, color the entire bullet.
Step 3. Insert the case and bullet into the chamber of the firearm and gently start to close the action. Stop as soon as you feel resistance.
Step 4. Remove the cartridge from the chamber, now look at the bullet, it should have well defined marks where the bullet contacted the rifling in the barrel.
Step 5. Continue seating the bullet deeper and chambering the cartridge until you only feel a slight amount of resistance when the bolt is closed completely. There should only be marks left on the bullet from the lands of the barrel.
Step 6. Now take another resized casing and with your bullet seating die set, repeat seating another bullet in the cartridge case to verify that this is your maximum cartridge overall length.
(NOTE) Never start working up a load with a bullet set against the lands in the barrel as this will sky rocket your load pressures.
Step 7. Shorten your cartridge maximum length by .06250" or 1/16" this is where you want to start to tune your load for seating depth.
(NOTE) Best overall accuracy, velocity, pressure uniformity and overall bullet performance will usually be obtained with most bullets seated from the barrels lands between .062" - .005".
RCBS CaseMaster® Gauging Tool.
|Centerfire Rifle Cartridges:|
|Resources And References:|