Weight matching lead bullets

[44Mo]

I myself seldom weight match bullets but I do randomly check bullet weights when I get a new batch of bullets to ensure consistency. This is more so when I purchase 1000 rounds or more at a time.
I will weight match if the bullets are found to be very inconsistent in weight; 20gr or more. (this has only happen a handful of times in my 20+ years of reloading)
This was a bench racing session of gun talk with two guys I shoot with.
1# states when matching bullets to exact same weight, lead is to be removed from the base of the bullet with a fine flat file. (not to deform the bullets profile)
#2 states, never from the bottom always from the top or sides. (affects charge to bullet distance for known given powder and charge)
Like I said I will only do it if it has to be done to ensure pressures on top end loads are not exceeded.
So I will rephrase the question to read: "If weight matching bullets become necessary, what is the best technique to achieve this?"

 

[robocop10mm]

How much weight difference are we talking? 1% difference in weights should be inconsequential. I would think messing with bullet profile or risking screwing up any angles would have more effect on accuracy than the weight difference.

If you insist on undertaking such an endeavour you should take material off the nose. The base is the last part of the bullet to contact the barrel. Messing up the base will have more effect on accuracy than messing up the nose.

 

[Texas1911]

The nose is the least consequential as Robocop said. The base, if filed improperly will allow gas to vent out one side prior to the other causing a heavy yaw moment on the bullet.

 

[44Mo]

There is something to this - i think!

The two individuals that prompted this tread both gave me 25 rounds of 44mag 240gr "LazerCast bullet"and 36 rounds of 9mm" 115gr hard cast" to test.
All head stamps matched, all case lengths matched, powder (per them) is no more than a 1/10gr variance, bullets weight matched.
This was the most accurate ammo I have ever shot!!!
At 6 yards one behind the other (1/2 group)
At 12 yards the group held other than the one I pulled on the 44mag.
At 25 yards 2/3 inch group.
This was not shot from a bench rest.
The 44 is a Ruger Redhawk with an 7 in barrel
The 9mm is a S&W 908 with a 3in barrel.
What was so surprising is how "Smooth" each round was.
The guy that files from the bottom is working on a Paten for the tools he has designed for accurately filing the bottom of the bullet.
I have loaded match grade ammo and shot other match grade ammo but nothing like this.
I went out to 50 yards with the 44mag and held a 1 1/2 group. (5 round group)
Well I just wanted to pass this along as it suprised me.
Maybe in the future will be seeing this guys tools for weight matchiung bullets.