RCBS Uniflow drum question

[RalphK22]

Can anyone show me a side by side comparison of a small and large Uniflow drum, or explain the differences? I just picked up what is supposed to be a small drum and it looks like what I already have, from memory. I have 2 Uniflows, both I assume are large drums, but I am not a home right now to compare.
Thanks,
Tom

[Raider]

Its not the drum size, both are the same diameter. Its the hole inside the drum. One is for small - pistol type charges - and the other is for large - rifle type - charges. Sorry, no photos.

Charlie

[Neumann]

The large drum has a bore diameter of 0.675", whereas the small drum is 0.500". I use the small drum for pistols, up to 25 grains or so (0.44 Magnum), which is well below the drum's rated capacity.

You might consider getting a micrometer head for the piston. It makes it easy to return to an established setting. I find it's a great time-saver when switching between calibers.

[RalphK22]

Thanks Guys, I realize it is the hole in the drum and not the dia. of the drum that determines "small and large drum". Looks like I'm stuck with another large drum from the measurement given. Man that ticks me off, I should know better than to trust sellers descriptions.

[Paul5388]

Midway has the small drum, but there may be others that have it at a better price.
Uniflow Powder Measure Cylinder Assembly Small

[Rule3]

Originally Posted by RalphK22

Thanks Guys, I realize it is the hole in the drum and not the dia. of the drum that determines "small and large drum". Looks like I'm stuck with another large drum from the measurement given. Man that ticks me off, I should know better than to trust sellers descriptions.

There should be a large and small metering assemblies (screw in )

Some models have a small, some have standard and some had both as a combo.

[ncbengal]

I had the same problem and bought what was supposed to be the "small" drum piston since the large piston is totally unsatisfactory for small pistol charges. As you might guess, the dealer did not know squat about the matter, and I was stuck with a part that did not work, and the dealer was 700 miles away. I called RCBS and pleaded my case, cried a few tears, and they sent me the right part (about $30 worth) at NO CHARGE. How is that for service!

[H Richard]

I bought my RCBS measure back when you got both drums with it. I put the small drum in it, and have loaded up to 53 gr. for loading 30-06. I have never had the need for the large drum.