RCBS Uniflow

[Charlie Two Tracks]

I have a RCBS uniflow powder measure and today I went and checked the weights of Unique out with it. On 10 drops, this is what happened.

1. 6.94
2. 7.04
3. 7.04
4. 7.22
5. 7.06
6. 7.04
7. 7.32
8. 6.94
9. 7.10
10. 6.88

on number 4 and 7 it felt like it was cutting grains or something. The drum would kind of catch and then let go. I checked the Mack-20 scale each time. I checked a drop with a check weight first to make sure it was reading right. Is this what is expected with Unique powder?:groner: My Lee Pro disc gets closer than that.

[HATCH]

On my Dillion 550, unique will go from 3.8 to 3.6 with 3.8 being what it was set meant to be.

[Matt3357]

Unique is a pain to meter, especially in small quantities. Do you have a powder baffle in your hopper? This will keep consistent pressure over the metering tube. You may have to do as some here and add a weight to the top of the powder. You'll just have to try and see what works best for you. This is one of the primary reasons I don't use Unique. There are so many other powders that meter so much better.

Matt

[bcr]

This is very interesting . . . I always had problems accurately metering Unique.

What is a good alternative that meters well (and I prefer clean, too)?

[GP100man]

I fixed my unique problem , I gave the rest of that #of powder away so I don`t have to go:groner:

[BillP]

I can't say for Unique but one of my Uniflows measure 2.3 grains of AA #2 with better than 1/10 grain consistancy. I use a baffle in this one. When benchmarking with my 20 yr old Uniflow I noticed the newer cylinder meters smaller and more accurately than the 20 yr old cylinder. I figure newer cnc machinery must be making the difference.

[glicerin]

Can we assume you're using the small metering drum? I would expect terrible consistency with the large drum. When I rotate the drum up to fill I always retract the handle slightly and tap up again. When I dump I repeat the tap(this replaces the hammer feature of the lyman 55. Works for me.

[Doc Highwall]

When I modified my RCBS uni-flow I put a longer handle on it and when the handle is in the down position it dumps the powder and when I bring the handle up I carefully tap the handle at the top of the stroke with the same force and number of taps then slowly lower the handle, this is where the longer handle gives me leverage and I have a powder baffle also. This seems to be my best technique for consistent throws. I think when you come down too fast with the handle centrifugal force throws powder out of the cylinder giving variations in charge weight, also hitting or tapping the powder measure too hard when filling the cylinder changes the packing density before rotating the cylinder causing variations also. The tapping technique to settle the powder into the cylinder I think some of the black powder shooters can relate to when they vibrate their loading blocks before they compress their powder charges to get consistent compression. Even the speed they drop the powder through their drop tube.

[Charlie Two Tracks]

I didn't know there were different drums. I must have the large drum. Where do you get a small drum?

[Doc Highwall]

Back when the uni-flow first came out they came with two drums now you get either the large or. the small

[kyle623]

they are 30 plus on most sites. good luck finding a used small drum. i've been looking for one for awhile

[Charlie Two Tracks]

I don't see but one drum. Can someone show me a site that shows the two of them? I'm having trouble finding it. thanks.
Never mind......... I found it at Midway USA. It is on backorder. I went and ordered the quick change cylinder with the small charge tube. Hope that works better.

[BillP]

Can we assume you're using the small metering drum? I would expect terrible consistency with the large drum. When I rotate the drum up to fill I always retract the handle slightly and tap up again. When I dump I repeat the tap(this replaces the hammer feature of the lyman 55. Works for me.


Yes, it's the small drum. It actually meters #2 down to 1.5 grains before crunching but I don't charge lower than 1.9. I only fill the hopper 1/3 to keep head pressure lower and use a baffle...but after checking several hundred loads I measure no difference with or without the baffle.

The large drum is close but no cigar when doing these pip squeak loads. RCBS sent me the small drum free about 2 months ago when I called and asked for it. It arrived 1st class mail a couple days later. As I mentioned already, the new cylinder measure small loads better than my older Uniflow with the small cyl.

[ricksplace]

I guess each uniflow is a law unto itself. My Uniflow is over 20 years old. I tap at the top and bottom, but I lower the handle quickly, to prevent the "cutting" action. Gives me the most accurate charges.

[Gee_Wizz01]

I have 3 Uniflows, the oldest is about 40 years old (I bought it new when I was in high school). and the newest is at least 8 years old. All of them measure extremely well for most powders. I cant tell any differences between the capabilities of the old and new measure. The newest measure came with plastic drop tube adapters instead of aluminum and the newer one has blued drums. I picked up two of these on E-bay for less than $30.00 each. When I use my uniflow I give it 3 light taps filling it and 3 light taps dumping.

G

[Throckmorton]

what we found on my buddie's Uniflow was to give the hopper 2 light knuckle raps befroe dumping the pwoder,even Unique measured spot on when we did this. kind of like Lyman's little 'knocker' on their press. I now do that on my dillon when using it too.

[winelover]

My older Uniflow always metered pistol powders well, including Unique. It wasn't till I started using the STICK powders for rifle that I encountered variations. That's when I started throwing lighter charges and then trickling the rest. I did this until I got RCBS Chargemaster and havn't looked back!

Winelover

[EMC45]

This is why my Uniflow is on the top shelf of my closet.

[ozonebob]

Charlie,

Hodgdon's Universal Clays is close to the same burning speed as Unique and it meters very well through both of my Uniflows. It s also pretty close in charge weight, too, so I don't use Unique any more.

Ozonebob

[Charlie Two Tracks]

Thanks ozonebob. I will give that a try.

[Mal Paso]

I didn't know there were different drums. I must have the large drum. Where do you get a small drum?

I called RCBS to buy the small drum and they sent it to me free!

[.357]

my unflow is a pain sometimes, actually i just sold it to a buddy, I picked up a lyman 55 from a member here to try and man it's night and day. I use a lot of unique so giving up the powder wasn't an option. The Lyman 55 was the answer for me.

[jonk]

That's why I have 2 dispensers.

Lee for stick powder and small charges of flake.

RCBS for ball and larger charges of flake.

Lee leaks ball powder like a sieve. RCBS binds on stick and some larger flake powders.

Both dispense very accurately with the powders they like.

[Westwindmike]

I just called RCBS. They said no way they would give me a rotor for mine. They want $36 for it. They were nice, just not in a giving mood.

[jeff423]

I use the Uniflow for several ball and flake powders and it works fine. I notice that with Varget it cuts the "rods". Is that a problem?

Jeff

[Doc Highwall]

jeff, cutting the powder is not a problem except it some times throws that charge out of your tolerance, just weigh that charge if you think that it felt different, that is what I do.

[rcbarry]

I use a Uniflow with a large drum. My powders are Bulls Eye, Unique, and IMR 4895. I have no problems with the metering at all. What I did was I added a baffle and it works great. I went to the local arts and craft store and bought a super thin sheet of tin and used a pattern that was given to me, cut it out with a pair of scissors and mission accomplished!

[GLShooter]

Never had any issues with Unique loads in the 45 ACP for performance. I don't do any of that tapping and knocking but I guess I'm not a good enough marksman to tell the difference when I'm shooting those El Presidentes just as hard as I can go. :-P

Greg

[Mal Paso]

I just called RCBS. They said no way they would give me a rotor for mine. They want $36 for it. They were nice, just not in a giving mood.

It was those Threads, in This Forum, saying How Wonderful RCBS Was got read by ATK who put a stop to it.:bigsmyl2:

I shoulda known better. Sorry

[Carolina Cast Bullets]

I have noticed that some in here have had problems with customer service at RCBS. My story:

My brother in law passed away not too long ago and I was given from his estate an RCBS Uniflow as well as a lot of other reloading stuff. The Uniflow worked but the metering screw, its lock nut and the drum were all very stiff. Disassembly showed a lot of powder residue on all three pieces. One call to RCBS had new parts sent to me within a week. The parts sent were the wrong ones, replacements came within a second week. All this with NO CHARGE, not even postage. The Uniflow was purchased in the mid 70's. It works perfectly now and very accurate with powders I use, mostly pistol powders. I cannot say anything bad about RCBS and their service.

[Skipper488]

I've noticed this with my powder throw too. To get more consistant throws I tap the side of the hopper 3 times everytime and it seems to be more consistant. Figuring that the vibration settles the powder into the cavity I can't help but wonder if I go to the adult toy store and buy a small vibrator and strap it to the mounting bracket if that would work.:cool:

[wallenba]

With mine I have to pull the rotor to the side while lifting and dropping the handle. Don't know why, but I get more consistant throws that way.

[mike in co]

any guess why i dont use unique ???

[c3d4b2]

I have had static charges cause me issues in the past. I would get a low throw followed by a high throw. Wiping the outside of the dispenser down with a fabric softener sheet help with the problem.

[huli]

Might sound dumb on my part but did you remember to put the baffle in the drum? Dont laugh ive done it! Steve:(

[geargnasher]

This is why my Uniflow is on the top shelf of my closet.
Mine's in a box under the bench.



That's why I have 2 dispensers.

Lee for stick powder and small charges of flake.

RCBS for ball and larger charges of flake.

Lee leaks ball powder like a sieve. RCBS binds on stick and some larger flake powders.

Both dispense very accurately with the powders they like.

True, but it seems I don't use the types of powder the Uniflow likes very much, Unique is certainly one of them.


any guess why i dont use unique ???

That and it's really dirty?


I fixed my unique problem , I gave the rest of that #of powder away so I don`t have to go:groner:

Yup.


This is very interesting . . . I always had problems accurately metering Unique.

What is a good alternative that meters well (and I prefer clean, too)?

Here ya go:


Charlie,

Hodgdon's Universal Clays is close to the same burning speed as Unique and it meters very well through both of my Uniflows. It s also pretty close in charge weight, too, so I don't use Unique any more.

Ozonebob



Unique is a pain to meter, especially in small quantities. Do you have a powder baffle in your hopper? This will keep consistent pressure over the metering tube. You may have to do as some here and add a weight to the top of the powder. You'll just have to try and see what works best for you. This is one of the primary reasons I don't use Unique. There are so many other powders that meter so much better.

Matt

Glad I'm not the only one who had issues. Unique worked better with my Lee Autodisk measures than any other measure I tried, but still wasn't happy with the powder.

Gear

[MtGun44]

"Clays is close to the same burning speed as Unique."

NOT! Clays is MUCH faster and peaks pressure VERY quickly compared to the
medium speed and benign Unique. Clays will overpressue in a .45 ACP before you
can make a standard 230 gr boolit match factory velocity.

I like and use Clays but it is nothing at all like Unique. Make sure you use Hodgdon
loading data - free on their web site.

Bill

[Sully]

Ive used Uniflow's off and on for better than 30 years. Always used a baffle in them and always "tap" the metering rod at the top and bottom of the stroke. Other than 700-X all the powders Ive used were (now) Alliants and Unique was tops among them. Never have had a problem.

Does it burn sort of dirty? Yeah...but then again I know how to clean a weapon!

[ozonebob]

Mtgun44,

You missed the word "Universal" from my reply. I agree that "Clays" is much faster than Unique, but Universal Clays is very close in speed to Unique.

Ozonebob

[geargnasher]

Dang, Bill, you had to go out of your way to miss that! He clearly said, and I quoted him above in post #36, "Hodgdon's Universal Clays", not to be confused with "Hodgdon's Clays" or "Hodgdon's International Clays". Universal Clays burns almost exactly like Unique in cartridges like .38 Spl. and .45 ACP, except much cleaner for the same pressures. The difference appears at higher pressures, where Unique is far more versatile.

Gear

[scb]

Uniflows are junk. Send it to me with the $20.00 fee and I'll dispose of it for you. ..................No, really I will. You'll never see it again and never hear any more complaints about this particular one.

[bbailey7821]

I can dispose of it for only 12.99! My overhead costs are lower in South Texas. Send it over and I'll handle the rest!

[c3d4b2]

I use to not respect the RCBS dispensers very much. Out of curiosity I ran a study on a RCBS and a Harrel. I threw charges of Reloader 15 with each (using the technique that works best for me), weighed each charge and ran a T-Test on the numbers.

The T-Test showed there were no significant difference between the measures. However, the RCBS had a lower standard deviation and a lower extreme spread than the Harrel.

I did not believe the test and reran it with the same results.

[Doc Highwall]

c3d4b2, the key word is technique. I believe a lot of people here do not try different ways with their powder measure to see what works with a particular type of powder.

[c3d4b2]

I agree that technique matters. I have spent time with the various techniques to get the most consistent results. I imagine I would get better consistency if I would use ball powders instead of stick powders. :confused:

I have used several powder measures and have not had more success with one type over the other. I have read that the best measure for stick powders is the Lee. I have one, but have not got around to running tests with it.

[John 242]

I fixed my unique problem , I gave the rest of that #of powder away so I don`t have to go:groner:

I fixed my Unique problem too...
I throw charges with my Uniflow, check them on my scale, and then trickle up until it reads right. Kind of slow, but it works for rifle charges loaded on a single stage.

For pistol loads on my progressive, I use Bulleye. Once the measure is set and I start rolling, there is very little variation. Bulleye runs through my Uniflow like poop through a goose.