Variation with same powder

[dmy]

I've been loading .223 Remington for all of 700 rounds, although I have reloaded tens of thousands of handgun rounds. So far, I have only used Winchester 748 in 1# containers and a RCBS Lil' Dandy with a fixed volume rotor. I use a #7, 8, or 9 rotor and throw it 4 times. I am pretty consistent with the rotors, however I noticed that weight varies from container to container. Using the same rotor, one container threw 25.8 grains and the next container threw 29.8 grains. I checked each container several times and pulled a few loaded cartridges because I couldn't believe my Franklin Armory digital scale. This was during one reloading session, so there was not a significant temperature or humidity swing.

Anyone else have this exprrience? I can understand +/- a few tenths, but not 4 grains.

[jericho89]

Same lot numbers on the powder or different lot numbers? You can have variations with different lot numbers.

[74c5]

You've got a packing density or grain density issue. Slightly smaller grains will put more mass in a given volume. Similarly, more dense grains will have more mass for the same volume.

[dmy]

These are different lot numbers from different containers purchased from different stores. I agree the density must be different. I have noticed a few tenths of a grain difference with the same container on different days. But 4 grains od difference with 25 - 29 grains of powder seems excessive. Enough to go from near minimum to maximum +P loads.

[Bill Steele]

I've been loading .223 Remington for all of 700 rounds, although I have reloaded tens of thousands of handgun rounds. So far, I have only used Winchester 748 in 1# containers and a RCBS Lil' Dandy with a fixed volume rotor. I use a #7, 8, or 9 rotor and throw it 4 times. I am pretty consistent with the rotors, however I noticed that weight varies from container to container. Using the same rotor, one container threw 25.8 grains and the next container threw 29.8 grains. I checked each container several times and pulled a few loaded cartridges because I couldn't believe my Franklin Armory digital scale. This was during one reloading session, so there was not a significant temperature or humidity swing.

Anyone else have this exprrience? I can understand +/- a few tenths, but not 4 grains.

I am surprised it is that large a variation. I have never noticed as I drop and trickle every rifle load. On pistol, I just check the weight once before I start loading on my progressive and then check the last charge dropped to make sure it didn't change.

Not surprising I guess, that I had not seen that before.

[milotrain]

I'm also suprised that the variation is that large. However I would recomend a few things right away.

1. Don't use traditional ball powders in 1lb lots, you are just asking for inconsistencies. Use them in large lots or use more contemporary ball powders that are known for lot to lot consistency and temperature stability. Even better, just use a good short grain stick powder.

2. Don't throw 4 times. This is not a "more is better" situation from a reduction in deviation by throwing twice. Throw once, or throw twice, get a sense of which is producing more consistent drops and do that. The Lee Perfect Powder measure is $25 and should throw 748 (and other ball powders) beautifully.

[bsumoba]

The Lee Perfect Powder measure is $25 and should throw 748 (and other ball powders) beautifully.

I sometimes I have issues with seepage of ball powders in my Lee powder throwers. I would have to tighten the screw down to prevent seepage, but that makes the lever harder to throw. In any case, I love these things as I do a gross charge (usually about 0.1-0.3 gr under desired weight), then hand trickle on an e-scale for precision handloading. For me, these are excellent for stick powders because I weigh each charge typically. I am very pleased with them and will be buying more when I get to my new house and have a dedicated reloading bench.

Since they are so cheap, I bought a bunch of them and have one dedicated to each powder. Set it to the most common charge weight and never have to worry about contamination or resetting the powder drop amount.

FYI, after every reloading session, I dump all the contents back into the jug AND I only keep one unit filled so there is no mix up.

I also do not have the hornady auto charger in the pic anymore.

[Bill Steele]

I too agree on the Lee PPM. I have bought some dreadfully expensive powder drops in my quest to find the perfect drop.

In the end, after my first few you would think I would have learned my lesson, but no, I would listen to some new "old timer" tell me about the Harrell, this, the zip gun hockey puck, that, all of which would drop 4064 like BLC2 and well, you know what? The Lee PPM did better than all the others. I only have a few, I think they will last me a very long time. But then, I drop and trickle, so I am not expecting 4064 to come out like BLC2.

[micro911]

I use Redding powder charge machine. I use V-140 for 223 and IMR 4064 for 308. My weight varies no more than about .3 grains. I think it is pretty consistent.

[opos]

While I've not used it for that powder I use the new Lee auto drum (not auto disc) measure and it's deadly accurate with 231, Universal, HP38 (same as 231)...I don't use it for stick rifle powders as I load them in very small quantities and hand weigh each one...I've heard others talk about how well they like the new Auto drum..maybe some have loaded with your powder.

I don't find much variation from bottle to bottle on anything that is the same lot number...I load a lot from 1# even though it's more costly than 8#'s because of convenience in storage..I never load to the max top end.

[noylj]

Just a point for others, since OP is a "seasoned" reloader.
Always shake the measure when you fill the hopper to help settle the powder
Always throw at least 10 throws (and return the powder to the hopper) before you EVER start to weigh the charge. Keep throwing until you get three that weight the same.
When you change the charge weight, throw at least 5 charges (and return the powder to the hopper) before you ever start to weigh the new charge weight.
Consistency is everything.
Folks who throw 10 charges and then weigh the total and divide by ten have no idea how consistent each throw was, only what the average throw was—and then they add to the craziness by reporting an extra place, such as reporting that they are throwing 23.82 gn, where they are really throwing 23.8gn +/- ?.? gn.
Weigh each charge.

[dmy]

I follow noylj's procedure almost exactly, except I tap my dropper pretty well before starting to weigh and/or loading. I also give it a few taps when I put the warm up drops back in the hoper and when I put the initial drops back into the hopper. I don't have the luxury of buying more than 1# containers because I buy over the counter. I do weigh at least 2 charges. If they are within .01 grains of each other, i start loading. If not, I keep measuring. I completely agree that consistency is everything. That is why I do not typically use my Lyman adjustable dropper because it is not as smooth as my RCBS Lil Dandy and therefore, not as consistent. While I did get a huge discrepancy between different contsiners, I measured it 6 times and all of my drops from the last container were within 0.2 grains of each othet. Most were with 0.1 grains. One thing which was unusual is that the plastic containers were sucked in like it was loaded at altitude before shipping. The container was still tightly sealed.