Bullet Weight Variability

[Jumpin4Joy]

I've been playing around with my Lyman 1000 scale and a new RCBS mini scale. Both seem accurate within .2 grain. Since I dont have a true weight check kit, I was using some loose Rainier copper plated and some off-brand lead wadcutters and semi-wadcutters for comparison.

I was supprised. The Rainier 115 grn 9mm bullets I have vary in weight by a range of .3 grains. The Rainier 125 38 spl bullets vary by as much as .6 grains. The off brand wadcutters at 158 grns were off as much as 5 full grains.

I'm certain that a .5 grain variation in powder is a bigger concern than a .5 grain variation in bullet weight....but why am I being so careful to measure everything out the the .1 of a grain on a 38 special round when the bullet weight can be off significantly. I have found the 9mm and 38spcl Rainiers to be sufficient for my shooting skill. What are some of your opinions on this matter?

Jeff

 

[Travis Two]

Years ago the NRA published a detailed article on bullet weight variations on 38 148 gr. wadcutters. If I remeber correctly weight variations up to 1.5 grs did not overtly affect group size that much and you needed to get to 3 grs of variance before things really started to go haywire. so anything under 1 gr varaiance would be excellent.

 

[Sunray]

A .2 weight variation isn't much. It's actually very good.
"...a .5 grain variation in powder is a bigger concern..." Yep. A half grain of powder can be the difference between one hole groups and an inch group. A half grain of bullet weight won't matter.