RCBS vs. Lee Powder Measures

[The Goose]

I thought this might be useful to some newer reloaders considering getting a powder measure. I have had a Lee Perfect Powder measure for several years and it has served me well. A few months back I bought a Lyman T Mag Turret press and wanted to get a powder measure to mount directly on the press. After some research I bought an RCBS Uniflow. This morning I was doing some reloading and used both measures so I thought I would post a comparison. First I loaded 200 rounds of .45 Colt on the T Mag using 6.2 grains of Titegroup powder. I weighed every 5th load. Roughly 50% of the time the load was dead on and the rest of the time the loads were .1 high or low. Later I loaded 60 rds of .22-250 on a single stage Rockchucker using 39.5 grains of H380. I am anal when I am working up a .22-250 load and I weigh every single charge right to the money. I set the Lee powder measure for 39 grains and trickled the difference. Roughly 50% of the time the load was dead on and the rest of the loads were .1 grains high or low. So different powders and different loads, but overall a similar consistency. The RCBS is new and cost around $70. The Lee has had literally thousands of loads put through it and sells for about $21 these days. I paid more like $12 when I bought mine. The hopper on the Lee can be easily removed to dump leftover powder while on the RCBS you have to run the powder out through the charger. I do not think the Lee can be mounted on the press and the RCBS can have a linkage attached for case activated charging.

In terms of a bench mounted powder measure the Lee fills the bill at a very reasonable price. There may be some really high end powder measures that give better reliability, I don't know. No one that I have ever spoken to has a powder measure that gets much better then .1 grains high or low. For that kind of accuracy I believe that one must weigh each charge. JMHO.

 

[Viper22]

Good review. I was looking at getting a powder measure for reloading .38 Special & .357 Mag. Looks like I'll be going with the Lee unit. If its cheap and works, great!

 

[lord1234]

I've been sort of unhappy with my RCBS uniflow. It does not seem to drop a very consistent charge. I've had 5 charges vary up to .5 grains.

 

[DukeInFlorida]

Here's an important consideration with the RCBS measure:

There are TWO charge size inserts that you can install.

The bigger one has a pocket diameter about the size of a nickel, and is really only for large capacity (typically RIFLE) rounds.

The smaller one has a pocket diameter about 1/3 the size of the larger insert. It's more for pistol amounts of powder.

If you're trying to dispense 4-7 grains of powder using the larger version, you will NOT be happy with the results. It will fluctuate all over the place. Change the insert over to the smaller size, and you'll be able to do 1/10th grain or tighter accuracy.

The "standard" measure comes with the standard insert (the larger one):
http://www.midwayusa.com/viewProduct/?productNumber=752260
The smaller insert dispensor comes with the smaller one:
http://www.midwayusa.com/viewProduct/?productNumber=295370

You can buy the optional inserts:
small one:
http://www.midwayusa.com/viewProduct/?productNumber=917289

From the Midway USA description for the "standard" one:
Please Note:

• There are two Micrometer Adjustment Screws available for the RCBS Uniflow Powder Measure which are NOT included. The Micrometer Adjustment Screw that you need will depend on the size of the cylinder in the powder measure. This powder measure has the large 11/16" cylinder and uses 654966.
  For reference:
• Large Micrometer Adjustment Screw (#654966) fits RCBS Uniflow Powder Measure with a measuring cylinder with a 11/16" diameter metering chamber. This is the Uniflow Powder Measure where the Metering screw is removed from the cylinder, up through the powder hopper.
• Small Micrometer Adjustment Screw (#322221) fits RCBS Uniflow Powder Measure with a measuring cylinder with a 1/2" diameter metering chamber. This is the Uniflow Powder Measure where the Metering screw is removed out through the threaded area of the cylinder.

When I have selected used ones on eBay to purchase, I only bid on the ones which include BOTH sizes of cylinder.
For example: Here's a good one to bid on, it has BOTH cylinders included:
http://cgi.ebay.com/RCBS-UNIFLOW-PO...emQQptZLH_DefaultDomain_0?hash=item2c51448658

 

[DukeInFlorida]

I have an issue with the powder dispensers which use a FIXED type cavity for dispensing powders. That type doesn't allow me to fine tune the exact amount of powder I want to dispense.

I would be stuck at 4.0 or 4.3 gr of a powder (for the two holes which would be in that size range), and I want to do 4.25 grains of powder. Can't do that with the fixed disk type.

I need to have a dispenser which has a screw (like micrometer) type adjustment.

 

[EC1]

Here's an important consideration with the RCBS measure:

There are TWO charge size inserts that you can install.

The bigger one has a pocket diameter about the size of a nickel, and is really only for large capacity (typically RIFLE) rounds.

The smaller one has a pocket diameter about 1/3 the size of the larger insert. It's more for pistol amounts of powder.

If you're trying to dispense 4-7 grains of powder using the larger version, you will NOT be happy with the results. It will fluctuate all over the place. Change the insert over to the smaller size, and you'll be able to do 1/10th grain or less accuracy.

The "standard" measure comes with the standard insert (the larger one):
http://www.midwayusa.com/viewProduct/?productNumber=752260
The smaller insert dispensor comes with the smaller one:
http://www.midwayusa.com/viewProduct/?productNumber=295370

You can buy the optional inserts:
small one:
http://www.midwayusa.com/viewProduct/?productNumber=917289

From the Midway USA description for the "standard" one:
Please Note:

• There are two Micrometer Adjustment Screws available for the RCBS Uniflow Powder Measure which are NOT included. The Micrometer Adjustment Screw that you need will depend on the size of the cylinder in the powder measure. This powder measure has the large 11/16" cylinder and uses 654966.
  For reference:
• Large Micrometer Adjustment Screw (#654966) fits RCBS Uniflow Powder Measure with a measuring cylinder with a 11/16" diameter metering chamber. This is the Uniflow Powder Measure where the Metering screw is removed from the cylinder, up through the powder hopper.
• Small Micrometer Adjustment Screw (#322221) fits RCBS Uniflow Powder Measure with a measuring cylinder with a 1/2" diameter metering chamber. This is the Uniflow Powder Measure where the Metering screw is removed out through the threaded area of the cylinder.

When I first used my uniflow measure, it came with the small insert. I was reloading 38/357 so it was fine with 2400. For a variety of reasons I switched to Unique. I found a lot more variation in the charge weights. On an old timer's recommendation I switched to the large insert and have had no problems since (that recommendation was made over 30 years ago). One factor that needs to be considered, whether you use the small or large insert, is the shape of the powder grains. Large or flaky grains appear to be better metered with the larger insert while smaller grains seem to work with the smaller insert.

 

[clerk.mvgc]

I'm sure veteran reloaders know this but when using a measure like the RCBS or similar (Lyman, Redding, etc) that are lever acutated it is important to "knock" the lever at the top and bottom of the stroke for accurate measurements. The "knock" makes sure the the hopper is full and the powder settles more consistently and the "knock" at the bottom of the stroke helps make sure the hopper empties fully.

 

[center442]

When I first used my uniflow measure, it came with the small insert. I was reloading 38/357 so it was fine with 2400. For a variety of reasons I switched to Unique. I found a lot more variation in the charge weights. On an old timer's recommendation I switched to the large insert and have had no problems since (that recommendation was made over 30 years ago). One factor that needs to be considered, whether you use the small or large insert, is the shape of the powder grains. Large or flaky grains appear to be better metered with the larger insert while smaller grains seem to work with the smaller insert.

Very true. I think the large "flatter" type grains get wedged and the measure almost has to chop through them, making for inconsistencies when you're dropping powder. The larger cavities give the granules more room to get pushed aside rather than chopped, so things flow smoother and more accurately. That's just my guess and I may be wrong, but my experience is that the more surface area that each powder granule has, the better they will work through a large cavity measure.

I'm sure veteran reloaders know this but when using a measure like the RCBS or similar (Lyman, Redding, etc) that are lever acutated it is important to "knock" the lever at the top and bottom of the stroke for accurate measurements. The "knock" makes sure the the hopper is full and the powder settles more consistently and the "knock" at the bottom of the stroke helps make sure the hopper empties fully.

Also very true. Some powder measures, like this one, from Lyman, even have a small swinging attached "knocker." When you swing the handle down to drop the powder you give it a flip with your finger and it keeps the powder settled and also makes sure that all the powder drops into the case and doesn't "bridge" in the drop tube.

I have the Lee powder measure, and it does work fine, but I find it a little light weight since it's all plastic. Make sure you follow the directions and run several hoppers full of powder to 'lubricate' it before you actually start measuring powder.