Why Different Weights

[forrest-hunter]

Regardless of what bullets or round balls I cast they is always a variance of 2-3 grains. I use Lee mold - bullets and round balls look perfect except for consistent wht. - using lyman #2 for center fire and lead for muzzle loaders

[JSnover]

What weights are you casting? 2-3 gr for a 200 grain boolit is just over 1% which isn't much to worry about.
Could be just the mold blocks expanding bit near the end of the casting session.

[shoot-n-lead]

That variance sounds about right for average casters...you will not be able to tell the difference in handgun ammo.

[Harter66]

I've been doing this 10 yr . I have it down to 2 gr top to bottom with about a .5 60% core in 35 to 45 caliber about half that in 22-32 cal AFTER visual culls . I note that because I'm a lot more picky about the keepers in smaller calibers .

The more I tweek my technique and improve my work flow the better they get .

There was a thread about consistency and how it applies at the pot and mould level . Good tools to be had from that thread .

Honestly I couldn't write down the methodology I use because it varies mould to mould and widely from a 5c aluminum 22 cal to singles of 45-50 cal .
I have a couple of moulds that drop up to 2 gr difference between cavities .

The most important thing I can think of is to pour as consistently as you can , same hight , same angle , same temp , same length of cooling time , same return to pouring position , repeat ......

[buckshotshoey]

Some commercial cast boolits would be jealous of you. I've bought commercial cast that didn't make 4 percent. Dont think about the weight difference and shoot em. You will never notice the difference.

[runfiverun]

yes same, same, same, same.
keeping the mold and alloy temp in a tighter window will narrow down the end results.

[Skunk1]

Lots of good advice. Consistency between different moldsand same alloy is the key. Different molds call for different methods. I have single and double cavity molds that are all there own creature. Patience also helps.

[pjames32]

Not really a bad spread. I tightened up my spread by doing an alloy mix and making ingots first. Then use those ingots in the pot when you cast. If you mix your alloy in the pot as you go there will be variations that can add 2-3% to your spread. YMMV

[gwpercle]

I had to stop weighing them.....all the little piles, should I increase/decrease powder charges to compensate....how much compensation is required .....they were driving me insane.

Now I visually inspect them . If they look well filled out , no wrinkles and a have perfect base , I load and shoot them. Forget weighing and sorting ....I'm just not that OCD-anal.

[robg]

I shoot 160 and 180 boolits with the same every thing else, at 100 to 200 yards point of impact is within my ability to shoot .at shorter distances with pistols etc doubt it would make enough difference to notice.

[WashingMike]

Because that's what happens when you cast boolits. Cast, shoot, pick 'em back up and repeat.

WashingMike

[John Boy]

Read this and you too can cast bullets with a Bell Curve Weight within 0.5gr ...
http://www.longrangebpcr.com/8Phases.htm

[KenH]

I shoot 160 and 180 boolits with the same every thing else, at 100 to 200 yards point of impact is within my ability to shoot .at shorter distances with pistols etc doubt it would make enough difference to notice.

Just so I understand here, you're saying you can mix 160 and 180 grain bullets, load the same powder charge, and get the same grouping? That 20 grain (10% difference in bullet weight) doesn't matter for grouping?

I just checked QL with a 30-30 load, 160 grain vs 180 grain - all other things equal, there was about 50 fps change. With a 10 grain difference in bullet weight, there was only 20 fps variance. Maybe I've been a bit too anal to keep bullet weights within 1 grain on a 170 grain bullet?

Ken H>

Ken H>

[robg]

I can usually keep groups to under 2 inches at 100 yards so the group of 160 g boolits group is overlapped by the 180 g group giving an overall group of about 3 inches .when I'm on form I can get groups of around 1 inch so using both weights give a group of about 2 inches which is within my average normal shooting .short range doesn't really show the true differences get further away then the variations shows up.or if I could shoot better.