RCBS Pro2000 Powder Measure question

[Rand McNally]

Anyone have a RCBS Pro2000? It has a micrometer built in to measure the powder. I don't understand how to use the micrometer to measure. What is the unit of measurement on the micrometer? Obviously it isn't per grain. The book says 6.8 grains of powder, I run the micrometer out to 6.8 and dump it in a casing. Then I measured it on a scale to make sure. BOY WAS THAT WRONG! Fortunately I am super paranoid so I check it constantly. But it would be nice to be able to get setup for different loads faster... The instruction from RCBS don't seem to be very detailed in how to use it, only how to set it up. Thanks!

[Seismic Sam]

The answer is pretty much the same for all powder measures: Don't go making unwarranted assumptions about how the measure is calibrated, and the only way to do it is to figure out the setting by measuring the weight thrown in a good reloading scale. I know the Lee Perfect Powder measure is actually set to measure in hundreths of a cubic centimeter, but I have no idea how my old Belding & Mull measure is set up and the settings on my Harrell measure appear to be even more arbitrary, although the Harrell measure can reproducibly be set to very fine adjustments.

In addition, your question has another very insidious and dangerous assumption in it that probably hasn't occurred to you yet: What made you think that your measure was marked to deliver the number of grains OF THE PARTICULAR POWDER that you were using?? All smokeless powdres have DIFFERENT densities, so if you set up your measure for a flake powder like Herco and then switch to AA#3 (fine grained ball powder with much higher packing density) and assume you're still getting 6 grains, you are probably in for a very nasty surprise when you pull the trigger.

I would suggest you take a time out, a re-read your reloading manual thoroughly, and then get back to reloading. For the record, you are the first person I have heard of who has made that assumption, and if you had been thinking in more detail about the variabilities in the nearly 100 powders out there, you would have realized that the powder variability alone would have made setting up a measure to directly deliver a certain weight of a particular powder a COMPLETE impossibility. In the future, check all your assumptions by referring to the manual, and even if you have the entire thing memorized, it doesn't mean you can leave your brain on "idle" while you're reloading. You always need to be asking yourself if you've set up everything right, and if you have loaded EVERY LAST ROUND CORRECTLY. Stay safe out there!!

[Rodentman]

Yeah, the micrometer is just an index, like on a Redding micrometer seating die (which doesn't give OAL). I weight several charges as I adjust the micrometer. When I get the right weight of the given powder I am using, I write the setting in my load book. Next time I load that bullet in that caliber with that powder I refer to the book, set the micrometer, and double check on the scale every 5-10th round. My 3BR measure replicates very well, but I double check anyway.

It's even more touchy when using the rifle micrometer for big bore loads like 30+g of H10. Micrometer gets touchy.

And some powders meter better, Trail Boss is especially light and airy yielding light charges more than I'd like.

[yuppiejr]

Anyone have a RCBS Pro2000? It has a micrometer built in to measure the powder. I don't understand how to use the micrometer to measure. What is the unit of measurement on the micrometer? Obviously it isn't per grain. The book says 6.8 grains of powder, I run the micrometer out to 6.8 and dump it in a casing. Then I measured it on a scale to make sure. BOY WAS THAT WRONG! Fortunately I am super paranoid so I check it constantly. But it would be nice to be able to get setup for different loads faster... The instruction from RCBS don't seem to be very detailed in how to use it, only how to set it up. Thanks!

Verifying the powder thrown from your measure matches what you expect when setting up a new load recipe is not paranoid, it's a fundamental step in the reloading process.

Based on advice I've gotten from others here, I ran an entire hopper of powder through my brand new Dillon just to make sure the internals were graphited up and working together as designed out of the box. I refilled, dialed it in to the measure I wanted (this took about 12 major/minor adjustments verified on a beam scale) and then dropped 10 charges to validate the average = exactly the amount I intended to drop before I started my first run. Each time I set-up and refill the powder measure on my press I'll do the same 10 charge verification after it's been adjusted and before I start a run even if it's the same powder as the last run.

The Dillon did not include a specific "this many turns = this much powder" instruction either (like your RCBS), presumably because the variances in powder density/granule size require you to verify actual charge weight rather than depending on an indexed setting that could easily be screwed up with disasterous consequences for the reloader. If your press's powder dispenser has some sort of index marks on it these are useful for making your own notes on the acual charge thrown for a specific powder at a given micrometer value. Over time, if you refer back to these notes, you should be able to use the data to have good starting point settings for a specific powder/charge which will limit how many adjustments you need to make and measure before you arrive at a desired value.

[recoilguy]

Verifying the powder thrown from your measure matches what you expect when setting up a new load recipe is not paranoid, it's a fundamental step in the reloading process.

Based on advice I've gotten from others here, I ran an entire hopper of powder through my brand new Dillon just to make sure the internals were graphited up and working together as designed out of the box. I refilled, dialed it in to the measure I wanted (this took about 12 major/minor adjustments verified on a beam scale) and then dropped 10 charges to validate the average = exactly the amount I intended to drop before I started my first run. Each time I set-up and refill the powder measure on my press I'll do the same 10 charge verification after it's been adjusted and before I start a run even if it's the same powder as the last run.

The Dillon did not include a specific "this many turns = this much powder" instruction either (like your RCBS), presumably because the variances in powder density/granule size require you to verify actual charge weight rather than depending on an indexed setting that could easily be screwed up with disasterous consequences for the reloader. If your press's powder dispenser has some sort of index marks on it these are useful for making your own notes on the acual charge thrown for a specific powder at a given micrometer value. Over time, if you refer back to these notes, you should be able to use the data to have good starting point settings for a specific powder/charge which will limit how many adjustments you need to make and measure before you arrive at a desired value.

This is exactly correct. It is a great way to obtain your starting point with a specific brand at a specific weight. Then when you get close the micrometer lets you know how much you have moved so you can determine easier how to hit exact amounts. A micrometer measures in 1/1000's of an inch and has no corrilation to weight on any way! For a 9mm 124g Montanan Gold FMJ both Titegroup and Vit N320 load very nicely at 4.0g. The adjustment is very very different between the two types pf powder. the 4.0 setting of Vit N320 would throw about 7g of Tite Group. Be very careful and never assume anything. good luck the RCBS Pro 2000 is a very good and accurate powder dispenser! A very good one!

RCG

[yuppiejr]

... But it would be nice to be able to get setup for different loads faster...

One other thought on the above point in your post... speed will come in time, focus on accuracy and safety first. Getting a powder measure dialed in was originally a bit daunting for me and seemed to take a lot of time/fiddling... now that I've done it a few times and on different equipment I'm a lot more comfortable setting it and getting an expected throw for each powder and I've found my speed improved as a result.

[Seismic Sam]

Oh, and one other trick about zeroing in your powder measure for each load: When you think you have the measure dialed in, throw ten charges in the pan, and weigh it. Say you're trying to get set up for 8.5 grains of Herco, and it looks like the measure is delivering that. With ten charges, you should be getting 85.0 grains of powder. If you get 85.3 grains, that means ON AVERAGE that your measure is throwing 8.53 grains rather than 8.50 grains. Notice how that extra decimal place showed up when you threw 10 charges??

NOW, THERE IS A VERY IMPORTANT CAVEAT TO THIS!! If you are loading ammo with a powder charge that is under the max charge by 5% or more, the above method will work nicely. If you are loading max loads, you have to weigh EVERY charge!! There is some variability in the amount of powder thrown by a measure and you do not want to be unwittingly putting 10.2 grains of Blue Dot in a 10mm case when the max load is 10.0 grains!!

One other thing to cutting down the variability in the amount of powder thrown: Keep the hopper over half full at all times, and throw powder charges by starting with the handle UP, which means the powder tube is down and connected to the hole to the powder hopper. So each time you go from handle up to handle down to handle up, rather than handle down to handle up to handle down. The reason for this is that it takes a while for the powder to run from the hopper into the tube, and a bit more time for the powder grains to finally settle and stop moving. If you only allow one or two seconds for the tube to fill, the weight may be less for a 1 second weight than a 2 second weight. Starting each throw with the measure tube connected to the hopper allows for the powder to settle while you're putting down one case and picking up another to fill.

[Rand McNally]

Yeah, after rethinking things last night, I see the flaw in my thought process. The world is much clearer this morning...

Thanks for the advice!!