RCBS Shortcomings

[Mags]

I'm more than a bit surprised by reports of powder charge accuracy issues .... we've been and still are using a manual Uniflow Powder Measure that came in a RCBS Rock Chucker Combo purchased back in the mid 60's .... it has 2 drums and a baffle in the hopper .... no clue how many tens if not hundreds of thousands powder charges it has dropped .... with our hunting loads we weigh and where necessary adjust each round .... over time we've used about every type of powder and don't recall any major issues

The issue here is with small measures, not the larger ones used in hunting rounds.

The Rock Chucker kit I bought included the Uniflow, but did not include the 2nd drum nor the baffle. I'm counting on the small measure drum we've purchased to remedy the small measure accuracy problems. Assuming it does, I would expect to see similar results, accurate ("tens if not hundreds of thousands powder charges").

Prior to tinkering with 380 loads, the smallest drop with the 'standard' drum', I was making was about 5gr up to the largest 37ish. No noticeable accuracy issues with it in that range.

[Mags]

I found (and ordered) the small drum from Primos Hunting here:
https://www.primos.com/priming-and-powd ... -9004.html

... I guess the Uniflow just works better with some powders and charge weights than others,...

Goes to what John Davies was saying about the ball powders.
Another thanks to Rifletom's info on the drum and baffle!

Side note, primos.com is part of the RCBS brand family.

[clovishound]

I use mostly Lee dies, I have one set of RCBS dies. Guess which one I couldn't get to work properly? RCBS CS was useless. They just had me redo the setup I had done at least 4 or 5 times already, and take a few measurements I had already looked at. In the end they half heartedly said I could send it in and they would look at it. A new Lee die that fixed the problem was probably cheaper than shipping back to RCBS.

[Hatchdog]

Understanding that the small cylinder for the Uniflow will most likely fix the small charge problem here is another solution. The RCBS Lil Dandy pistol powder measure. I had one of these for quite a while but sold it when I got my electric powder dropper. The downside is the need to purchase different rotors for different charges as they do not adjust but that is what makes them so accurate. Just another option for all to consider. Quite frankly I was surprised the find RCBS still makes them, seems like everything from the old days is gone.

https://www.rcbs.com/priming-and-powder ... 86040.html

[Mags]

Understanding that the small cylinder for the Uniflow will most likely fix the small charge problem here is another solution. The RCBS Lil Dandy pistol powder measure. I had one of these for quite a while but sold it when I got my electric powder dropper. The downside is the need to purchase different rotors for different charges as they do not adjust but that is what makes them so accurate. Just another option for all to consider. Quite frankly I was surprised the find RCBS still makes them, ...

https://www.rcbs.com/priming-and-powder ... 86040.html

The little Dandy does look like another option. Looks like it is on sale too, couple bucks more than the small cylinder. The rotors are $9 a piece though and powder specific for any given charge. So powder could be another expense if one doesn't already have the powder for that rotor.

Rotor chart download https://www.google.com/url?sa=t&rct=j&q ... uc26G6jtr3

... seems like everything from the old days is gone.

The reason I decided not wait on purchase of the small cylinder.

I also notice that the newer mechanical measures include the baffle and supposedly better metering at the small measure end. Specifically the 'Quick Change' and 'Competition' models.

[Mr. Neutron]

Got my smaller drum/cylinder for my Uniflow II powder throw from RCBS today. Went right to work on gettin' it installed and put to use.

First, I have to give Kudos to Rifletom for mentioning this smaller cylinder was even "a thing". I had no idea that RCBS made a small charge cylinder for the ole Uniflow II. Also, thanks for the help from John Davies for mentioning to use a sperical powder instead of the flake type powders. Great advice. I just wish I could take advantage of it, for my handgun reloads anyways. I pretty much only have very old Bullseye and Hodgdon's Universal powders on hand. Neither of these are what I consider "wonderful" metering powders, especially the Universal.

But with the small charges (2.8 grains of Bullseye) for my .380 ACP, it worked SO MUCH better than the same powder throw did with the larger cylinder. Bullseye still doesn't meter as well as Win 231 did for me in my Dillon 650, but with the new cylinder, it managed to pretty much stay mostly within +/- a tenth of a grain of my desired 2.8 grains. And it did it much more reliably than with the bigger cylinder. For me, this is acceptable for some ammo I just wanna plink away with using a short barreled handgun. I loaded up 50 rounds of .380 with 95 grain Lead Round Nose bullets tonight. After spending some time to get it dialed in to my 2.8 grain target, I checked the charge on my scales after every 5 rounds. As said above, it held within the width of the lines on my RCBS beam scale up or down from the alignment lines. Probably around a tenth or so of deviation?

Mags mentioned using this smaller drum for the "bigger" charges used for our .30-30s, so I used it for 12 rounds of .30-30. Using Winchester 748, the small cylinder seems to meter as well as the bigger one I've used forever. This 748 is just a really fine metering powder. Hodgdon's H335 was close to how the Winchester meters, but had slightly more deviation. Not enough t worry about though.

So far, I'm happy with this powder throw for now. With the help from here and the smaller cylinder gizzie, it works much more reliably for my pistol powders I currently have on hand.

My really old school reloading stuff........

IMG_0428.JPG (3.88 MiB) Viewed 1713 times

[Mags]

Got my smaller drum/cylinder for my Uniflow II powder throw from RCBS today. ....

The small charge cylinder I ordered hasn't arrived yet. I did receive the baffle.
I do have #2 and #5 that JohnDavies mentioned, so I can check them out as well as a couple other powers I have. I have some doubts though about how well #2 and #5 will measure out at the small end after looking at the LittleDandy Rotor Charge table. Not recommended. We'll see. Glad to see confirmation the small cylinder works out for the .30-30 loads. I'll be checking Leverevolution and I4895.

[Mr. Neutron]

Is Leverevolution a spherical powder? H4895 is a stick (extruded?) powder, right? Be interesting to see how those one meter with the smaller cylinder.

[Mags]

Is Leverevolution a spherical powder? H4895 is a stick (extruded?) powder, right? Be interesting to see how those one meter with the smaller cylinder.

Lever is spherical. I have IMR4895. I think it is extruded. I haven't opened the bottle. I would expect it to measure OK (31.5-33.5) for .30-30 150gr bullet. We'll see.

[Rifletom]

Got my smaller drum/cylinder for my Uniflow II powder throw from RCBS today. Went right to work on gettin' it installed and put to use.

First, I have to give Kudos to Rifletom for mentioning this smaller cylinder was even "a thing". I had no idea that RCBS made a small charge cylinder for the ole Uniflow II. Also, thanks for the help from John Davies for mentioning to use a sperical powder instead of the flake type powders. Great advice. I just wish I could take advantage of it, for my handgun reloads anyways. I pretty much only have very old Bullseye and Hodgdon's Universal powders on hand. Neither of these are what I consider "wonderful" metering powders, especially the Universal.

But with the small charges (2.8 grains of Bullseye) for my .380 ACP, it worked SO MUCH better than the same powder throw did with the larger cylinder. Bullseye still doesn't meter as well as Win 231 did for me in my Dillon 650, but with the new cylinder, it managed to pretty much stay mostly within +/- a tenth of a grain of my desired 2.8 grains. And it did it much more reliably than with the bigger cylinder. For me, this is acceptable for some ammo I just wanna plink away with using a short barreled handgun. I loaded up 50 rounds of .380 with 95 grain Lead Round Nose bullets tonight. After spending some time to get it dialed in to my 2.8 grain target, I checked the charge on my scales after every 5 rounds. As said above, it held within the width of the lines on my RCBS beam scale up or down from the alignment lines. Probably around a tenth or so of deviation?

Mags mentioned using this smaller drum for the "bigger" charges used for our .30-30s, so I used it for 12 rounds of .30-30. Using Winchester 748, the small cylinder seems to meter as well as the bigger one I've used forever. This 748 is just a really fine metering powder. Hodgdon's H335 was close to how the Winchester meters, but had slightly more deviation. Not enough t worry about though.

So far, I'm happy with this powder throw for now. With the help from here and the smaller cylinder gizzie, it works much more reliably for my pistol powders I currently have on hand.

My really old school reloading stuff........


IMG_0428.JPG

I have one of those older cans of Hercules 2400. Still good! Glad the small drum worked for your needs.

[220]

One other tip, I average ten throws when adjusting the Uni-Flow. That takes care of the slight variations. Since I am math impaired, it is easy to just drop the last digit to calculate the average figure.

John Davies
Spokane WA

Some good advice, I do likewise throwing 10 charges and taking an average and adjusting the thrower on the average.
I also run a small drum, some variation is to be expected but with very light charges you should be able to hold it within 0.1gr. Yes you dont want to be to gentle in operation but the real secret is consistency and operating the handle with the same force and speed each time. A baffle also helps although regularly topping up the hopper to keep the powder level consistent also helps.

[Mr. Neutron]

On the subject of the small drum for an RCBS Uniflow II, I was kinda pleasantly surprised to come across this video from GunBlue490:

https://www.youtube.com/watch?v=LzGaPv_3oWQ&t=1928s

I'll warn some folks that his videos tend to be kinda long, but he always makes some very good points based on numbers, and experience. I personally really like learning from this guy.

He happens to be working with the same powder measure I have, and mentions that he likes the small drum the best. He feels it's more accurate and repeatable than the large cylinder I previously had in my measure.

He also goes into the numbers of how a tenth of a grain (or more) really has very little affect on where a bullet impacts at various distances. I'd guess that a coupla tenths variation up or down in a case with the capacity of, say, a .30-30, wouldn't change the outcome of shots at "open sight" (or longer) distances. Shooting out in the field likely gives us more variables than a grain or so of powder could ever change (especially with ME pullin' the trigger).

Just more food for thought........

[JEBar]

Yes you dont want to be to gentle in operation but the real secret is consistency and operating the handle with the same force and speed each time. A baffle also helps although regularly topping up the hopper to keep the powder level consistent also helps.

BINGO!!

[Mags]

Yes you dont want to be to gentle in operation but the real secret is consistency and operating the handle with the same force and speed each time. A baffle also helps although regularly topping up the hopper to keep the powder level consistent also helps.

BINGO!!

Again, with very small measures this does not help with inconsistencies using the standard cylinder.

[Mr. Neutron]

Loaded 24 rounds of .30-30 with 33 grains of Win 748 and Hornady 170 flat points this afternoon, using the new (small) cylinder. I weighed each charge with my RCBS beam-type scale. I guess I have "commitment and trust issues" when it comes to building faith in a sorta new-to-me reloading process. After getting the powder charge set, the scale never varied more than the width of the narrow marks on the stationary scale base and the mark on the beam. Very stinkin' tiny, insignificant amounts of variation of the powder charges. But this new setup was really consistent and repeatable today. Seemed to behave the same with my small amount of 2.8 grains of Bullseye for my .380 as well. I'm likin' it.

[Mags]

Loaded 24 rounds of .30-30 with 33 grains of Win 748 and Hornady 170 flat points this afternoon, using the new (small) cylinder. I weighed each charge with my RCBS beam-type scale. I guess I have "commitment and trust issues" when it comes to building faith in a sorta new-to-me reloading process. After getting the powder charge set, the scale never varied more than the width of the narrow marks on the stationary scale base and the mark on the beam. Very stinkin' tiny, insignificant amounts of variation of the powder charges. But this new setup was really consistent and repeatable today. Seemed to behave the same with my small amount of 2.8 grains of Bullseye for my .380 as well. I'm likin' it.

Good to see the inconsistencies knocked when using the small cylinder. Keep the updates coming.

[GFK]

Mags, I noticed your tag line. I guess you are aware of this: https://youtu.be/a3lk9Uu6Rxw

[Mags]

Mags, I noticed your tag line. I guess you are aware of this: https://youtu.be/a3lk9Uu6Rxw

Thanks for sharing the video.
I kew of the temporary court decisions. But first I'd seen a good explanation. Next court date is Dec 23.

[Mr. Neutron]

Loaded up some .380 ACP today for my little Ruger MAX LCP. Thought I’d throw some ear muffs on, and go outside and function check a few rounds. And saw this goofy mole on top of my grass, doing a 45 mph breast stroke kinda deal across the yard. How fortuitous to have a weapon at just the right time!!!!!

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Oh, yeah………. The small cylinder worked great for the small charges it threw for the .380 today. Repeated well. Any minor variations (less than a tenth, I’d guess) are more likely due to the Bullseye powder than the powder throw itself. Made some ammo with it that very possibly saved my life from a charging (well, it was actually scootin’ away……) mole at 3 feet!

[Mags]

Finally had some time today to look at the SMALL measure cylinder compared to the cylinder that ships with the Uniflow. I looked at Accurate #2 and #5 that JohnDavies suggested and Titegroup.

Off the Shelf Uniflow.
The smallest measure I could get with the off the shelf Uniflow was with the measure screw 1/8 turn open. Any tighter and the cylinder would not rotate. For Accurate #5 and Titegroup, I could not get consistent drops. The variance I would not be too concerned about if these were at rifle load scale, but for small caliber pistol this variance is significant. Only Accurate #2 gave consistent drops good enough for 380. Since the measure screw itself couldn't get any tighter, I could not get down to 32auto drops with any of these powders.


Uniflow with Small Measure Cylinder.
I got consistent drops with all 3 powders. Good for 32auto and 380. This with 3/4 turn measure screw open. Since I got what I was after for 32 auto I didn't pursue tighter measure screw turns.
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