double disk

[trixter]

Which two disks ( Lee ) to use for 17 gr of unique?

Thanks

[Rick O'Shay]

Going by the chart. Use a 1.09 on the bottom and a .76 on the top. If that does not through 17 grains try a 1.02 bottom and .82 top to go down in weight or 1.18 bottom and .71 top to go up.
Hope that helps. Do you have the chart that came with the disks?

[skeettx]

See here :)

http://leeprecision.com/cgi-data/instruct/AD2302.pdf

and for fun reading

http://castboolits.gunloads.com/showthread.php?108688-Lee-Double-Disk-chart

[trixter]

Thank you

[troyboy]

In my experience Lee's chart is conservative, just a start point.

[44Vaquero]

Yes, the disks are purposely conservative by design. I usually have to move up at least one cavity sometimes 2 depending upon the powder being used. Powder density can vary quite a lot and still be considered within spec by the manufacture. Lee having originally touted the safety-disk system as not requiring charges to be verified by weight, designed them intentionally on the conservative side.

[Moonie]

I calibrate my powders regularly, I drop 10-20 charges, weigh them and divide the number of charges and divide them by the cc's of the cavity. This gives you the volumetric displacement of your specific batch of powder. I write this down on the containers. Makes it easier to come up with the right cavity for the charge you need.