Bullets

One of my friends recently told me they sort bullets by both weight and length of their bearing surface (the part of the bullet that comes in contact with the barrel, illustrated below).  I hadn’t thought of that before, but you could see how variations in the bearing surface length obviously impact the amount of barrel friction on the bullet and therefore cause variations in muzzle velocity. For virtually all of my precision shooting I use Berger bullets, and I wondered if there was even any measurable variation in their bearing surface because their quality control is so much tighter than other ...

Like most things in handloading … the more uniform one round is to the next, the more uniform ballistics you can expect.  That is why I weight sort my bullets, and for my match grade ammo I only load bullets that have exactly the same weight (+/- 1/10 grain). I recently weight sorted a box of Berger 7mm (.284) 180 grain Match Grade VLD Hunting bullets, and here are the results: Average = 179.89 grains Standard Deviation = 0.085 grains Extreme Spread = 0.4 grains Extreme Spread as % of total weight = 0.2% (this is amazing) Bullet: Berger Bullets 180 ...

Although some people claim the bearing surface of a bullet (the sides of the bullet that touch the rifling as it travels down the barrel) has more impact on a bullets flight, variations in weight also have an impact although the degree of impact is up for debate.  We can all agree that a 35gr bullet would fly much differently than a 80gr bullet shot out of the same rifle.  But is does a 54.8gr bullet fly noticeably different than a 55.3gr bullet? Regardless of whether there is a measureable difference based strictly on bullet weight, I believe the weight of the bullet is strongly correlated to the bearing surface.  To ...