How to tell if RCBS Uniflow has the large or small drum?

[FergusonTO35]

Hey folks. I have an RCBS Uniflow and would like to get the small micrometer adjustment screw for it. How do I tell if it has the large or small drum?

[Artful]

Small
http://media.midwayusa.com/productimages/880x660/Primary/917/917289.jpg

Large
http://i925.photobucket.com/albums/ad94/JimKirk_2010/WEB/de224177.jpg (http://s925.photobucket.com/user/JimKirk_2010/media/WEB/de224177.jpg.html)

[abunaitoo]

Remove the powder adjusting screw from the drum.
Bushing/base and all. Like if you had to change the drum.
On the small drum, the powder side head will be about 1/2".
On the large drum, it will be about 3/4".

[KnotRight]

Per RCBS tech support
Small = .5000
Large = .6875