Unexpected powder weights

[majordisorder]

Can anyone help me out with this?

I've just loaded my first batch of .45ACP with three different powder charges. I used my new Lee Auto-Disk to measure the (Unique) powder using the supplied disks.

I've found that the charges are a "step" out, so I was trying for 5.6 gr so selected the ".61" disk, this threw 5.2 gr, when I went up to the next disk size ".66" this threw 5.6gr rather than the expected 6.0gr. The same was also true of the ".71" disk which should have done 6.5 but dropped 6.0g. Has anyone else found this to be the case with Unique?

I double checked the positioning of the disk and had plenty of powder in the hopper. I did a total of 30 rounds and weighed around 30% of them, they we all out by the same amount. Any ideas?

[ovenpaa]

Is this down to the shape/density of the powder? I have seen this with other Culver type throwers, as an example 45 grains of SP9 is 8/1 on mine..

[spud]

some powders can hang in a culver type thrower try lowering the baffle to releive the weight iof the powder in the hopper from the powder about to drop threw the dispencer

[phaedra1106]

How much powder have you got in the hopper?, they tend to work better when 1/2 full or greater. First thing I did on my 2 is throw away the normal hopper and replace it with the hopper from the Pro Auto-Disk powder measure, this has an Elastomer wiper and works a lot better.

[ovenpaa]

I use a Harrells Premium Powder Measure and always run it full to the top when used. Having said that it is only used for one load in one rifle so it does not come out very often...

[majordisorder]

Thanks for the replies. I had the hopper about 1/2 full, maybe a little less. I'd assumed that the size or density of the powder had changed since my instrutions were printed?

I'll have a look around for the Pro hopper, can you buy these separately from the rest of the measure? I'll load some more tonight with a totally full hopper to see if that makes a difference too.