Weighed vs Measured Pistol Charges

[Gus Youmans]

During the previous powder shortage in the late 2000's I acquired a large quantity of Red Dot powder because it is useful in both shotgun and pistol loads and it was available. I found that a load of 4.0 grains under a Falcon Bullets (no longer in business) commercial cast 125 grain truncated cone bullet shoots well in a number of different .38 Special and .357 Magnum revolvers. Red Dot is a flake powder and does not meter well, sometimes showing a deviation of plus or minus .3 grains with the chosen 4.0 grain load. I was bothered that Red Dot metered so inconsistently through the powder measures and wondered how accuracy was affected. A test was devised to determine the effect of the inconsistency on paper.

The first step was to determine the consistency of my powder measures commonly used on progressive machines. Hand operated powder measures were not considered. The powder measures are a Lee Auto Disk, Lee Auto Drum, two RCBS Uniflows (one old and a newer one), a Hornady Lock N Load, and a Dillon. One hundred charges were weighed from each measure to an accuracy of .02 grains on my electronic balance and the result entered into a spreadsheet and then average, standard deviation, and extreme spread were calculated. In order to more accurately replicate the reloading process, one hundred fired cases were loaded into the case feeder, resized with a .38 Special resizing die with the decapping pin removed, charged with powder, removed from the press, and the powder charge weighed. The powder measure selected to reload the test ammo was the Lee Auto Disk because it was the least consistent (highest standard deviation) of the bunch.

The next step was to find a revolver that shoots the 4.0 grain Red Dot load well. Four Smith & Wesson revolvers were selected for testing, one each Model 686, Model 66, Model 65 and Model 15. Four, six shot groups were shot at 25 yards from each gun using a Ransom rest and the Model 15 was the clear winner. No special care was taken in reloading the test ammo.

Next, 192 pieces of new Starline .38 Special brass were primed with CCI500 primers using a Lee hand priming tool. Ninety-six of those cases were loaded using the powder measure and the other ninety-six cases were loaded with weighed powder charges held to plus or minus .04 grains. The weighed charges were charged with powder from the powder measure, removed from the press to adjust the powder charge, and returned to the press to complete the loading process. This ensured that all the cases mouths were expanded the same.

I wanted to be able to get an average group size for the sixteen, six shot groups as well as a single aggregate group for all ninety-six rounds. That required the use on one target as a base target and another target stapled on top of the base target that was moved every six shots to expose a clean area for the next six shot group. Walking downrange 32 times was much more time consuming that I thought it would be.

The results were surprising in that there was little difference between the measured and weighed groups. The average group size (16 groups) for the weighed rounds was 1.59 inches while the average for the measured charges was 1.64 inches. The aggregate of 96 shots was 2.84 inches for the weighed rounds and 2.94 inches for the measured rounds. Smallest and largest groups for the weighed rounds were .98 and 2.00 inches versus 1.23 inches and 2.12 inches for the measured rounds. Velocity was measured but the data lost due to replacement of the hard drive on my laptop. I suspect that if the test had been conducted at 100 yards instead of 25 yards the results would not have been nearly as close.

I still weigh charges that are at or near max but measure almost everything else.

Gus Youmans

[Tim357]

Thats quite a write up, thanks for the legwork. I realized years ago that ammo factories do not weigh their powder, they throw charges in every instance once they figure out a suitable charge for whatever powder they are using for a given load. As for me, i quit weighing charges for handgun loads once I found a suitable load. With a measured load, the volume of powder is the same every time regardless of weight. If another lot of powder is heavier than the previous lot, the volume is still the same. If a given charge is lighter from another lot, again the volume is the same, and the powder column is the same. I cannot shoot well enough to tell the difference on target. These are my observations, right or wrong. Looking forward to other's experiences as well

[Outpost75]

Powders of large particle size do not meter as uniformly by volume and are best in larger cases in which the powder charge variation by volumetric metering does not exceed 5 percent of the mean. Perfectly OK in .45 Colt Cowboy loads, but not ideal for .45 ACP wadcutter for 50 yards slow fire. I prefer for machine loading in the Dillon, or Star powders of smaller particle size which will meter within 1-2% of mean charge weight in .38 Special, .45 ACP or 9mm.

[Polymath]

I came across a difference in Trailboss from one can to another. Sat down to think about it for a bit. Came to a conclusion as to why my loads were getting lighter on the second day of loading.
Ambient moisture at the time of manufacture. We are very dry up here especially in winter and the moisture evaporates out. So If I'm close when I open a fresh bottle, and the volume is where I want it, then I don't worry too much as the volume is what it is.

[dverna]

During the previous powder shortage in the late 2000's I acquired a large quantity of Red Dot powder because it is useful in both shotgun and pistol loads and it was available. I found that a load of 4.0 grains under a Falcon Bullets (no longer in business) commercial cast 125 grain truncated cone bullet shoots well in a number of different .38 Special and .357 Magnum revolvers. Red Dot is a flake powder and does not meter well, sometimes showing a deviation of plus or minus .3 grains with the chosen 4.0 grain load. I was bothered that Red Dot metered so inconsistently through the powder measures and wondered how accuracy was affected. A test was devised to determine the effect of the inconsistency on paper.

The first step was to determine the consistency of my powder measures commonly used on progressive machines. Hand operated powder measures were not considered. The powder measures are a Lee Auto Disk, Lee Auto Drum, two RCBS Uniflows (one old and a newer one), a Hornady Lock N Load, and a Dillon. One hundred charges were weighed from each measure to an accuracy of .02 grains on my electronic balance and the result entered into a spreadsheet and then average, standard deviation, and extreme spread were calculated. In order to more accurately replicate the reloading process, one hundred fired cases were loaded into the case feeder, resized with a .38 Special resizing die with the decapping pin removed, charged with powder, removed from the press, and the powder charge weighed. The powder measure selected to reload the test ammo was the Lee Auto Disk because it was the least consistent (highest standard deviation) of the bunch.

The next step was to find a revolver that shoots the 4.0 grain Red Dot load well. Four Smith & Wesson revolvers were selected for testing, one each Model 686, Model 66, Model 65 and Model 15. Four, six shot groups were shot at 25 yards from each gun using a Ransom rest and the Model 15 was the clear winner. No special care was taken in reloading the test ammo.

Next, 192 pieces of new Starline .38 Special brass were primed with CCI500 primers using a Lee hand priming tool. Ninety-six of those cases were loaded using the powder measure and the other ninety-six cases were loaded with weighed powder charges held to plus or minus .04 grains. The weighed charges were charged with powder from the powder measure, removed from the press to adjust the powder charge, and returned to the press to complete the loading process. This ensured that all the cases mouths were expanded the same.

I wanted to be able to get an average group size for the sixteen, six shot groups as well as a single aggregate group for all ninety-six rounds. That required the use on one target as a base target and another target stapled on top of the base target that was moved every six shots to expose a clean area for the next six shot group. Walking downrange 32 times was much more time consuming that I thought it would be.

The results were surprising in that there was little difference between the measured and weighed groups. The average group size (16 groups) for the weighed rounds was 1.59 inches while the average for the measured charges was 1.64 inches. The aggregate of 96 shots was 2.84 inches for the weighed rounds and 2.94 inches for the measured rounds. Smallest and largest groups for the weighed rounds were .98 and 2.00 inches versus 1.23 inches and 2.12 inches for the measured rounds. Velocity was measured but the data lost due to replacement of the hard drive on my laptop. I suspect that if the test had been conducted at 100 yards instead of 25 yards the results would not have been nearly as close.

I still weigh charges that are at or near max but measure almost everything else.

Gus Youmans

Excellent report Gus.

[jmorris]

100-200 yard benchrest matches are won all the time by people using volume thrown charges and the winner is the one with the smallest one hole group at those distances. Finding the “node” is obviously of benefit.

Most pistol/component/distance of target combinations are not accurate enough to realize any benefit.

[dverna]

100-200 yard benchrest matches are won all the time by people using volume thrown charges and the winner is the one with the smallest one hole group at those distances. Finding the “node” is obviously of benefit.

Most pistol/component/distance of target combinations are not accurate enough to realize any benefit.

My experience as well. Weighing charges is about on the same list of anal activities as cleaning primer pockets on pistol cases.

BTW, read one study where thrown charges actually delivered better accuracy than weight charges. This was done with a bench rest rifle but I cannot recall the powder used.

There is also the study done at "The Warehouse"

Interesting read:

https://precisionrifleblog.com/2013/10/18/secrets-of-the-houston-warehouse-lessons-in-extreme-rifle-accuracy/#:~:text=The%20warehouse%2C%20owned%20by%20Virgil% 20King%2C%20included%20a,revealing%20experimentati on%20into%20practical%20rifle%20accuracy%20ever%20 conducted.

And the Myths busted:

Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.
Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least.

[David2011]

With difficult powders like this I often resort to my old Lil' Dandy for which I have a full set of rotors.

[Three44s]

I make red dot look like a different powder in metallic cases simply by inside flash hole deburring my cases.

Once I witnessed that I began performing the treatment to ALL my cases, every cartridge, all powders, no exceptions.

Some one claimed that a change in lot numbers does not affect accuracy and I take exception to that claim. I have seen it both ways but in varmint calibers it can most certainly make or break a sweet load.

I have seen varmint rifles that will delivery the goods with a span of charges and in some loads, some rifles that the accuracy node is more narrow. I greatly prefer a load I can throw over weighing but it just comes down to the powder, the cartridge and the rifle.

Three44s

[Buck Shot]

I've read that the benchrest folks, who often use nothing more than a volumetric powder measure, often don't even bother weighing charges in part because the mass of a given volume of powder will go up and down quite a bit with relative humidity.

I use RD in several of my 38 Special loads, and I throw charges with an RCBS Li'l Dandy measure with the aftermarket adjustable rotor. It doesn't meter as consistently as Bullseye, but it's good enough for my (low) shooting skill level.

[Rich/WIS]

The Lyman 55 works well with flake powders like Red Dot, Unique and Blue Dot. These are my cast boolit rifle powders. Don't know about pistol charges as those get Bullseye from a fixed rotor measure.

[375supermag]

Hi...
I weighed every charge for years in handgun loads.
As my volume of shooting and number of calibers increased, I started using a Little Dandy powder measure and only weighed every tenth charge. I can see no difference in accuracy out to 50 yds between weighing every charge or by dumping charges with my powder measure. I have a complete set of rotors for my Little Dandy.
I use an RCBS powder measure and an electronic scale for loading rifle cases or full power loads in heavy loads in large caliber hand gun loads using H110/W296 in .41 and .44Magnum plus the .357Max and .375SuperMag and I weigh every charge in those calibers. Mostly only load those calibers in 100 or so batches, so weighing each individual charge isn't that time consuming.

[Baltimoreed]

I also weighed every load that I threw when I first started reloading but finally realized it wasn’t needed for ipsc and cas quality pistol loads and eventually only bothered weighing my deer hunting loads.

[Char-Gar]

I have never weighed the charges on more than a few rounds at a time. All production powder charges are thrown. On some longer stick powder, I throw many back into the measure hopper, because the throw didn't feel right. I never go anywhere near the pressure red line and thrown charges have always targeted well for me. I suppose in some National Championship match, I might weigh charges, but probably not.

[GregLaROCHE]

I used to always throw a light load and trickle up to the desired weight. More and more I’ve simply been letting the Lyman 55 do all the work and try to believe in it. I’m shooting those rounds for more or less plinking. My precision shooting is now done with muzzle loaders and BP. I do however use the 55 to charge my dosers with BP. I think BP is a lot less critical than smokeless.

[Daekar]

I am not a precision shooter, but I have taken to weighing charges when doing ladder testing and once I pick a load I just use a volumetric thrower. My results are actually more consistent that way than weighing each charge, and it is a LOT faster.

[Buck Shot]

The results were surprising in that there was little difference between the measured and weighed groups. The average group size (16 groups) for the weighed rounds was 1.59 inches while the average for the measured charges was 1.64 inches. The aggregate of 96 shots was 2.84 inches for the weighed rounds and 2.94 inches for the measured rounds. Smallest and largest groups for the weighed rounds were .98 and 2.00 inches versus 1.23 inches and 2.12 inches for the measured rounds.

Interesting. Thanks for doing the legwork and writing it up for us. I'm a fan of thrown charges for handguns (I use RCBS Little Dandy with the aftermarket adjustable rotor) and this gives me additional confidence in my SOP.

For 223 rounds for SR competition at 200 and 300, I also usually throw all charges, weighing every 10th charge...I only weigh charges for ammo at the 600 (not that it probably makes any difference for my skill level)...

[Gus Youmans]

Buckshot,

Back when I was shooting high power rifle competition I also measured for 200 and 300 yards but weighed for 600 yards. One of my high master class shooting buddies shot the same ammo with measured charges at all three yard lines and never dropped a point due to inconsistency of his ammo. He might have faired a point or two better on windy days at 600 yards if he has used different bullets and weighed his powder charges but, to him, it was not worth the time and aggravation.

Gus Youmans

[farmbif]

this reminds me of when I got my first 357 mag, oh how I miss that gun today, a nickel plated 6" smith and Wesson found at the pawn shop for $125, first order of business was to go to village sports for a box of 500 jhp158's a set of lee dies with the powder scoop included, I no longer remember what powder I got but the shells, a big bag of once fired I got in my travels, were filled with that little black powder scoop, and they all went bang.

[Livin_cincy]

Very nice posting. Thank you for sharing. There is much confusion over " precision" when it comes to handgun verses long range rifle. Hopefully your post will clear up some.

There is a great misunderstanding of volume and weight of a charge. Designing a powder to meter accurately in both volume & weight is challenging. We don't verify a purchase of powder by counting kernels. We measure a volume and weigh it.

The industry is creating precision powder dispensing scales. This lets us feel assured we have consistent charges. But we ignore consistent volume. We don't have a precise way to measure volume other than throwing a charge thru a powder measure. A tool to make a variable volume in cubic centimeters with precision would cost more than a digital powder measure scale.