Thrown (Volume) Charges vs. Weighed Charges — What is Better?
When we first ran this story a year ago, it spurred a hot debate, with strong opinions on both sides of the issue. Some guys argued vehemently that volumetric powder dispensing was best — citing the experience of short-range benchresters, most of whom still throw their charges. Others say weighing your charges is best, so long as you have a very precise, and very repeatable scale. We know some of the top 1000-yard shooters weigh their charges to the kernel.
The Great Debate: Volume vs. Weight
Most competitive long-range shooters weigh powder charges for their handloads. Some even use ultra-precise magnetic force restoration scales to load to single-kernel tolerances. But is weight-based measuring always the best way to fill a case with powder? Another option is volumetric charging. This method fills a precisely-sized cavity with powder and then dumps the charge into the case. A Harrell’s rotary powder measure works this way, as does the sliding powder filler on a Dillon progressive press.
Lower ES/SD with Precise Weighing
For long-range applications, most people believe that precise weighing of powder charges is the best way to achieve optimal accuracy and low ES/SD. Our testers have definitely seen ES/SD go down when we started weighing charges with a lab-grade force restoration scale. However, those short-range Benchrest guys still do pretty darn well with their thrown charges, at least at 100 and 200 yards.
Our friend Dennis Santiago recently observed something that made him scratch his head and wonder about weighing charges. His AR-15 match rifle shot better with volumetric (cavity-measured) charges than with weighed charges dispensed by an RCBS ChargeMaster. Here’s what he reports:
Cavity vs. Dribble (Dennis Santiago Report)
I had the chance to compare nominally identical ammunition loaded two ways. These were all .223 Remington match loads using 77gr Sierra Match Kings over 23.4 grains of Hodgdon Varget. Same gun. However I loaded some ammo with charges dispensed with a Lee cavity-style powder measure while other rounds were loaded with powder weighed/dispensed by an RCBS Chargemaster. The cavity-drop ammo (with powder dropped from the Lee unit) was consistently better than the weighed-charge ammo. I have no idea why…
So, ladies and gentlemen — what do you think? Why did Mr. Santiago’s volumetrically-charged ammo shoot better than ammo filled with weighed charges? What’s your theory? Gary Eliseo suspects that Dennis’s Chargemaster might have been drifting. What do you think? Post your theories in the comments area below.
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- Weight vs. Volume — The Great Debate
- The Great Debate — Weight vs. Volume in Powder Dispensing
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Tags: Chargemaster, Dennis Santiago, Force Restoration, Lee Powder measure, Volumetric
I weight my charges but with that said ive found it near impossible to get a better group with weighted charges versus thrown charges. What sounds good doesn’t always play out on the target. I believe from my testing 90% of the group is all about barrel and bullet selection.
The RCBS Chargemaster can be less precise than a volumetric powder measure in certain circumstances. It’s a strain gauge scale and RCBS only claims +/- 0.1 grain precision and that is after rounding. So we’re really talking a 0.3 grain ES. With a powder that meters well (ball, Varget, etc.), a decent volumetric powder measure can keep its ES < 0.2 grains.
If I were going to do this test, I would choose something other than a Chargemaster to weigh charges with. They are good units, and convenient, but they only claim +- .1 gr. which is not nearly as good as the scales that are commonly used by long range competitors. Also, although I would not have believed it, with the right technique Varget can be thrown to closer tolerances than one might otherwise believe possible, and despite its low price and inexpensive materials, the Lee powder measure has a good reputation for accuracy of charges.
Think for a minute how accurate the scale that is combined with charge master can be , even chinese lab scales accurate to 0.1 grain cost 500+$ so what can be excepted of a 50$ scale used in chargemaster
I’m guessing that the data here is not that extensive. Also, one is likely not to notice much difference out to 600 yds.
A good old beam scale is hard to beat for accuracy.
Just trying to gain some perspective here.
So if I’m seeing an ES of 5-6 now bowman much is this worth and would I be able to see the difference on target at 1000 yards, especially given the variance in the environment from shot to shot?
23.4 of varget what kind of case fill is that. I think there is something to the way the powder is filled into the case. like is it lofted filled or drop densely filled. I believe how the case is charged can change how well the powder burns. Short range bench rest you drop a dense charge and shoot it right away.
My initial thought was “Well of course weighed charges are more accurate”. But I do wonder how much of a factor humidity plays in power weight. If powder moisture content makes a measurable difference in charge weights then possibly an accurate, repeatable metered charge is the more precise approach. Would like to learn more about this subject.
I once worked in the Photo Lab for an aerospace company and one of my duties was to assist the QC Department test and maintain all of the test and measuring instruments for the company including all of the digital scales. I was taught that three things were the enemy of accurate measurement with any digital scale.
Power fluctuation and noise, vibration and static electricity.
I use a Trip-Lite model UltraBlock428 Line Conditioner as well as ferrite line filters at each end of the power cable (1 should be sufficient but I have a ton of them) to ensure I have clean, stable power. I place a heavy Granite Surface Plate on a sheet of closed cell foam to isolate and dampen vibration. I save all of my dryer sheets and use them on the pan, measuring stage and powder hopper before each session. During the Winter I also use anti-static spray once a month. This pretty much has eliminated drift and I attribute the rare over throw to the powder grain size fluctuations. I am getting 1 overthrow out of 50. Hope the Horde finds this of interest.
My charge master throws +/- 0.15gr excluding over charges. With a brass flow restricting insert (bought of eBay) the number of over charges goes down and the tolerances tighten up.
My Lee Auto disk throws very tight charges with fine grained pistol powders. I bought a rifle adapter but haven’t tried it yet. I imagine with long extruded powders like Varget there will be some shearing.
It would be interesting to see mean, standard deviation and extreme spread numbers for bench rest level charge weight option. I’d like to see how calibrated beam scales compare to charge masters and calibrated powder drops.
Why not weigh the charges thrown with the dispenser on the chargemaster scale?
My guess is the two charges are not identical and the thrown charge is working out better in terms of harmonics and exit timing.
I use a RCBS 10-10 Scale tuned by Scott which does not drift and is far more accurate than a Chargemaster imho.
Weight and mass are not the same. The weight of a powder charge is not the deciding factor for consistent and low E/S. It is the mass which matters, hence the better accuracy achieved with thrown charges.
One can not prove volumetric accuracy through the use of a scale just like you can’t prove the accuracy of a scale via volumetric consistency.
Two different forms of measurement
The short fat powder column has been proven to be more inherently accurate. I think throwing off a powder throw gives a more consistent powder column height.
Take 3 cases and weigh it to .02 and be very consistent to how you fill the powder in the case. then take the same powder charge weighed to .02 then use three different case fill techniques three different powder columns see what happens.
Many years back “Precision Reloading” published an article comparing volumetric vs weighed charges and also found volumetric charges more accurate. Certainly, not intuitively obvious but here we go again.
Like Rich said, weigh a run of thrown charges – but prepare to become very disturbed by the results. Just like kernels stack to different heights in case, so to in charge thrower. For those that weigh or measure bullets to sort them, there would really no choice, if you didn’t weigh charges, the pressure variances would negate any small benefit of sorting.
One things for certain. If the bench resters could get better groups by weighting charges they would be doing just that.
One man’s experience. Some years back I bought a Lyman 1200 DPS3. Being obsessive I started by check weighing each charge on my Hornady Pacific balance beam(I have a set of test weights, and it’s accurate). Went through all the manual procedures, warming up ahead of time, calibration, etc. I couldn’t get two charges in a row that were the same, and I don’t mean differences of one/tenth of a grain. The differences were often half a grain or more. I tried adjusting for drift after every charge. Made no difference. I’m sure some people must get decent results from these electronic devices, but I couldn’t. I’ve never loaded a box of ammo with mine. It’s much less stressful to use a powder measure, alone for short range, and trickle up for long range precision.
A long time ago I quit trying to use my Chargemaster because it was so slow. Then I tried throwing sub-weight charges from my Redding measure and using the Chargemaster as an oversized electronic trickler. Worked for me, but I am shooting minute of Bambi..
The downward pressure of the column of powder in the charge thrower also affects the density of the kernels in the charge thrower. It lessens with every powder throw. But even if it were constant, the analogy is filling a truck bed with bricks, dumping them in with a front end loader, until the bricks are exactly even with the top. You would never expect any two payloads to weigh very close to the same.
I weight m’y powder… shooting compétition. loading with m’y 308. Consistency is key to grouping. According to rifle id say its better to volumétrie charge du to action and shaking of other bullets im magasines…. a charge weight for a ar-15 application wouldnt beneficiate thé same consistency due to powder packing up in other bullets on each shot…wich thé volumetric centrifugal dispender does.
Shaking of ar-15 action. Packs powder in magasines ammo… similar to volumetric centrifugal dispender using vibrations for better filling. at some point wiegthed charges doesnt have same consistency in ammo as thé volumetric ones… is like gas and air, in a combustion chamber.. where à good spay mist in needed instead of à wall weting.
I throw charges from an RCBS measure that are slightly under-weight then tune them up using a Target Master electronic trickler. This is as quick as using my Lyman DPS3 but eliminates drift and gives much more consistent charge weights. I then throw the powder from the pan into the case via a funnel with a drop tube. I’ve not compared charges metered or thrown in different ways, but the method above leaves me confident of its consistency.