Working with Bullets
• Don’t substitute bullets without going back to the load data.  There are subtle variations in weight (both total and sectional), composition (lead, copper, alloys), bases (flat, hollow, boattail) and thickness of jackets or plating and bases that affect ballistic coefficients, pressures, velocities - and therefore load data.

• What’s the real difference between plated and jacketed? Jacketed bullets are formed around a lead core (look for the lead base of the bullet) or have lead poured into the jacket “cup” to form the bullet.  Plated bullets have the plating deposited in a very thin layer via chemical or electroplating.  Plated bullets have a much thinner coating than jacketed.  Because of this thinness, the load data for plated bullets is identical or near-identical to that of lead.

• When using cast lead bullets, utilize a separate crimp die for best results.  Seat the bullet in one step with the seating die and then either remove the seating plug and readjust the die or utilize a dedicated crimp die.

• Bullets with a cannelure are seated to the cannelure and roll crimped.  Bullets with no cannelure, such as plated bullets are seated to recommended COAL (Cartridge Over All Length) and taper crimped for best performance when loading in magazines. Rifle bullets are often not crimped, as neck tension holds them securely in place.

• What to do when you can’t (easily) find the load data for a particular bullet?  Check for load data from powder manufacturers.  Contact the bullet manufacturer via email or phone.  As a beginner, don’t load bullets you don’t have data for.  For advanced reloaders, compare overall geometry, ogive, composition and weight, carefully working up a load in direct comparison to similarly published data.

• What’s ogive?  What’s the impact of ogive? – The ogive of a bullet is roughly defined as the curved part of the bullet that gives it it’s classic shape.  A more formal definition of ogive [link] includes the concepts of conical or tangent (Spitzer).  Ogive has a significant impact on bullet seating depth and COL, as the ogive of a rifle bullet can never safely touch the rifling (even if the pointed tip of the bullet has entered the rifling on a chambered round).  For pistol cartridges such as the .45 Auto, selecting a bullet different ogive characteristics can allow a loaded cartridge below maximum COAL to engage the rifling.  (I learned this the hard way when a round fit the case gage perfectly, but otherwise wouldn’t go into battery as the plated bullet engaged the rifling.  Extracting the bullet dumped the powder.  Lesson learned.)

• How should I match bullet diameter to case expansion? As a general rule, expand the case mouth 0.002” larger than the intended bullet for jacketed bullets and expand 0.003” to accept lead bullets.  Expander plugs should be measured and labeled with their diameter – especially if you have multiple plugs in your die set.

• Should I always choose bullets with the lowest ballistic coefficient?  Ballistic coefficient is an indication of resistance to drag – and not fit for purpose.  For long-range accuracy on recreational targets, it may make the most sense to choose bullets with the lowest ballistic coefficient.  For hunting, other bullet characteristics are more critical concerns.

• The load specifies a “heavy roll crimp” for a particular load -  what does that measure to?  Empirically measuring crimp can be performed with a micrometer and can be observed with a magnifying glass.  A heavy roll crimp should only be used on bullets with a cannelure and is often specified for magnum loads in cartridges that headspace on rim, such as the .357 Magnum.