Help mould drops to heavy

[whomeno]

I got a Lee 125 gr rn mould that is dropping 126 to 129. I am using WW with 3% tin less solder added. Is their something I can do to get the weight down?

[tazman]

You will need to go to a different alloy such as linotype to get the weight down.
That said it is quite common to have a mold drop a few grains heavy.
The few grains you mention would have little to no effect on your loads. Just start with a low powder charge and work your way up to an accurate functioning load. I personally would not be concerned about the weight difference you mention.

[Dale53]

tazman is correct. Bullet weights as described depend on a particular alloy (the standards vary from manufacturer to manufacturer). Nothing to be concerned with.

FWIW
Dale53

[whomeno]

ok thanks

[RobS]

Molds weights are a consideration to what the company specs the mold to drop with their alloy (whatever that might be). Being 1-4 grains over you are not in a "worry" position. Regards to pressures with your current boolit/caliber more will have to do with seating depth than the few grains difference.

[theperfessor]

Remember that all parts have a tolerance, and slight variations in size and profile of the mold cavity combined with variations in alloy composition can easily make the actual bullet weight vary as much as 3-5%. As has been mentioned, many other parameters such as seating depth will cause pressures to change more than a 3% variation in projectile weight. Besides, you're supposed to work up to max loads and pay attention to pressure signs when you do, right? This would take a slightly heavier bullet into account.

I wouldn't worry about it, I have lots of different brands of molds made of all different types of materials and none of them cast a bullet of exactly the stated weight.

[HeavyMetal]

There is a slight difference between clip on WW and stick on ww metal, mixing them "Willy Nilly" will result in some variation in weight per batch of alloy used / made.

I will suggest seperating the two types of weights for future use and try your 3% lead free solder additive. I think you'll find this will bring you back into the "correct" ball park if you feel the need.

Next question: are your boolits running one or two grains heavy or, and this is important, are the fluctuating 4 or 5 grains per batch of alloy?

Casting a bit heavy is not unusual and will not affect accuracy, but a "lot" cast from the same pot of alloy with a 5 grain "window" is unacceptable for me, particularly in a 125 grain boolit!

Not a flame just trying to figure out what I really need to tell ya, LOL!

[MtGun44]

Completely irrelevant for any practical situation if mold is a few percent off of nominal weight.

Bill

[HATCH]

It's a lee mold
You want exact weights using your alloy then get a accurate molds mold.

[HATCH]

The reason the mold may drop different weights is your alloy isn't properly fluxed in and you are getting separation.
Kinda like oil/water in a glass

[fredj338]

Not sure what the issue is, just load them & shoot them. Unless you are using the exact alloy & casting temp, you are rarely getting the stamped bullet wt in any mold. A few gr diff in wt will not affect your load data.