Powders And Powder Measures

     Use a good reloading manual to find starting loads and types of powder to use. I strongly recommend the Lyman Cast Bullet Handbook, First through Third Edition.

     Alliant, Winchester, IMR, Accurate, Hodgdon and others make smokeless gun powders.

Wads

     This discussion of powders makes mention of wads that are used to hold the powder against the primer. You must understand that many shooters have written that shooting cartridges with wads over the powder has caused “rings” in their rifle chambers. The ring is described as an annular ring in the forward end or mouth of the chamber. I have never ringed a chamber in thousands of shots fired with wads. Be aware that there is a risk

Powder "Bridging"

     Sometimes, with some powders, all the powder doesn't come out of the measure when the measure is operated. The next charge or the next can then be much larger than the planned or "set" charge. The powder gets hung up in the measure and doesn't come out on the first try, but comes out along with the proper charge later.

     While charging cases with SR4759 using a Lyman 55 powder measure on 10/16/04, I had two instances of the powder not all coming out of the measure after flicking the knocker. This is two out of eighty-eight cases charged. I didn't measure the first instance. Note that this has happened many times in the past, 10/16/04 was the first time I ever measured what happened.

     In the second instance, the measure dropped 5.6 grains of powder into the scale pan after flicking the knocker.

     After operating the handle and flicking the knocker again, the measure dropped 21.7 grains of powder into the scale pan. The powder that didn't come out before came out then. The desired charge was 14 grains of SR4759.

     On 11/29/05 while testing a Lyman 55 powder measure there were two hang-ups. The charge was 18 grains of SR 4759.

     One hang-up was charges of 4.3 grains, .4 grains, 0 = zero grains and 68.2 grains.

     The other hang-up was 7.8 grains, 0 = zero grains and 41.9 grains.

     While testing a powder measure designed and made by Mike Barrett, I had SR4759 hang-ups several times, to the point where I stopped testing the measure with SR4759.

     In February 2006, while testing a Lee Perfect powder measure and old 20 mm cannon powder-sorta kinda 4831, John Alexander had a hang-up or bridging problem.

     R. Dale McGee reported having powder hang-ups with 700X powder.

     There have been reports of Red Dot powder hang-ups.

     These experiences and reports suggest that some of the high-pressure incidents reported may be caused by powder bridging in the measure, with the next charge being excessive.

You MUST look in each charged case with a flashlight!

     There are many powders suitable for cast bullet reloading, more than anyone can test in any reasonable shooting career. The powders listed below are ones I have used and tested over the years. They work for me, and they’ll work for you as you get started.

     Powders can be broadly classified as “Fast” and “Slow” based on their burning rate. Fast powders include pistol and shotgun powders that are designed to burn quickly. Slow powders are designed for maximum velocities in long barreled rifles.

     Many cast bullet reloaders use fast powders. Because fast powders are used in small charges, it is possible to double-charge a case without having the powder overflow the case. When using fast powders, it is mandatory that the reloader use a light and look into every case to make sure that none are double charged. Every time. Or you’ll blow up a gun. Double charges of fast powders are dangerous.

     "When checking the charges in bottlenecked cases it is sometimes inconvenient to get a good look at the powder down inside there. It is much easier to use a probe of some kind. I have taken a twenty-penny galvanized nail and chucked it in the electric drill, then spun it against the grinding wheel to reduce the nail head’s diameter enough so that it will easily pass thru a 30 caliber case neck. Then the pointy end is likewise ground flat and square. Now I have a probe that will enter 22 caliber cases with the small end and 30 caliber and up cases with the big end. I filed a series of marks on the shank so it is easy to tell when the charges in a loading block are all the same because the same mark is always at the case mouth.

     Checking the charges in 38 Special and larger straight cases is easy if you use a short piece of 3/8 inch wooden dowel which has been marked with suitable calibrations on the side. Drop it into the charged case, note the mark nearest the case mouth, and repeat for the rest of the cases. I also use the dowel to check the charged case in my Lee Loadmaster without removing the case from the press." John Bischoff

     Some cast bullet reloaders use slow powders, generally to get higher velocities. Fast powders will give lower velocities. Increasing the charge of a fast powder will increase pressure more than velocity; so dangerous high pressures result before high velocities are reached. Increasing charges of a slow powder will increase velocity and pressure sort of simultaneously. It is difficult to double-charge a case with a slow powder without the powder overflowing the case.

     Be aware that there have been reports of high pressure incidents when using small charges of slow powder. Don’t use less than the recommended starting load of slow powders.

     Small charges of fast powders don’t fill up much of the case, and sometimes the gun is sensitive to the position of the powder in the case. Rifle shooters can minimize the effect by raising the muzzle before each shot, this places the powder back against the primer.

     There are so many powders suitable for reloading with cast bullets that the average reloader doesn’t have time enough to adequately test them all. Here are some comments on powders that I have used with some success.

     These are all fast powders except IMR 4895:

• IMR 4227

Does not seem to be very sensitive to position, and I have almost always been able to get good results using it without a wad. Works very well in single shot rifles and in cartridges from 223 Rem. to 45/70.

• H 4227

Hodgdon makes this powder that is almost the same as IMR 4227. It seems to work as well as IMR 4227. I now use IMR 4227 exclusively for the sake of consistency. Either powder will work, but you should stick with one or the other. (In late 2006 I read that Hodgdon will stop making H4227 and continue making/selling IMR4227. Hodgdon bought IMR in the past year.)

• SR 4759

This is the most accurate powder for over-37-caliber cast bullet shooting that I have used.

     There are two problems with this powder:

     First, SR 4759 has big kernels and it can be difficult to run through a powder measure. For bench rest shooting charges must be weighed.

     Second, this powder can be hard to find. For some years it wasn’t made, now it is, but there are shortages from time to time.

     This powder does seem to be sensitive to position, and I have generally had better results with a wad than without. Another way of saying this is that I have been able to get good accuracy with SR 4759 and a wad, and almost as good accuracy with larger charges of SR 4759 and no wad.

     Light charges of SR 4759 used without wads frequently leave unburned kernels of powder in the barrel. I get better accuracy more consistently when I increase the load until no or almost no unburned kernels are left in the barrel. Using a wad with a proper load eliminates the problem. SR 4759 was discontinued by Dupont many years ago, and re-introduced a few years later. In 1993/1994 SR 4759 was again unavailable for a few months. We were nervous. I have no idea whether SR 4759 will become unavailable again, but many shooters have laid in a substantial supply. I have never found a powder to give as good or as consistent accuracy in the 38/55 or 45/70 as SR 4759.

• Accurate Arms #9 (AA #9)

This powder has become quite popular in the past few years. I have used it in my .30/30 bench gun with excellent results. This is a "ball" powder that measures easily and very accurately through the powder measure.

• Alliant Unique

This is an amazingly versatile powder; it can be used in handgun cases and rifle cases all the way up to the 45/70. Unique gives me almost as good accuracy as does SR4759, without weighing the charges. For all but the most demanding shooting I use Unique in the 45/70 at ranges up to 600 yards. It also works well in the 30 calibers, the 7MM TCU, 6.5X55 and 243. It works well in every cartridge case from 22 Hornet to 45/70.

• Alliant 2400

Gives good to excellent results in .30 and .32 calibers. Bill Crowley came to a match at Old Colony a few years ago and cleaned our clocks using 2400 and a rifle he made himself. Several of the more fickle of us immediately broke out the 2400 and tried to work up loads, with little success. But it worked for Bill.

• Alliant Red Dot, (and infrequently Blue Dot and Green Dot)

These are used by some shooters in the smaller calibers. Ed Harris wrote about a universal load of Red Dot for many cartridges.

• IMR 4198

This was used more in the past than it is now. It doesn’t meter well through the powder measure because of the large grain size. This powder is excellent in other applications, but it won’t do anything for me in lead bullet loads that other powders won’t do better.

• IMR 4895

This is a slower powder that works well with reduced charges. It is said that 60% of the starting load for a jacketed bullet is a reasonable starting load for a same weight cast bullet with this powder. I like IMR 4895 because I sometimes get good results at higher velocities than I can get with faster powders.

The "Next" container of powder

     When a container of powder gets low, I pour the remainder into the next container of powder, and roll the container around, mixing the old and new. When a container of Unique gets low, I pour it into a new container of Unique, and roll and turn the new container. I kind of think that this mixes the new and old, and reduces any variation from lot to lot. I asked for comments about this practice on several of the Cast Bullet forums, and was cautioned about surplus powders. I don't use surplus powders, and never have. Canister powders, the powders available from the big time makers like IMR and Alliant and Hodgdon and Winchester, are somewhere between identical and almost identical from lot to lot. Surplus powders have identifying numbers-like "WC 820", but it seems that there can be wide variation, lot to lot, of surplus powders with the same identifying numbers. Loads have to be worked up for each lot. In the case of these surplus powders, it was recommended that we do NOT mix the little bit in the current container with the next container of powder. Some claim that gunpowder makes a good fertilizer, and recommend putting that last bit on the cabbages.

     Powder Measures vary in price from the reasonable to the frightening. The Lee Loader comes with a powder dipper. Lee also makes a set of 15 dippers for under $10 that will serve the careful beginner well. I use the dippers now and then; they work very well for duplex black powder loads with over-powder cream-of-wheat fillers.

     A scale is necessary to set a powder measure.

     I use the Lyman 55 powder measure out of habit; I bought my first in 1960. It works well most of the time, gets a little crunchy with SR4759 or IMR 4895, but they all do. I'm not sure that lots more money means a lots better measure.

     It tells us that flicking the knocker should be done when the handle is down when the measure is delivering the powder. Some folks flick the knocker when the handle is up-when the rotor is being filled. I'm an Up Knocker. And it reinforces my belief that every case should be inspected with a flashlight after charging.

     Scales come in many brands. I've never had a bad one. I use an RCBS 10-10 scale out of habit. It stores in itself and has a cover, so it can be transported to the range without damage.

     There are also several brands of electronic scales available costing two to three times as much as a beam balance scale. An electronic scale will speed up bullet or powder charge weighing. Many shooters use electronic scales. I don't. There have been reports of accuracy problems with some electronic scales.

     "When checking the charges in bottlenecked cases it is sometimes inconvenient to get a good look at the powder down inside there. It is much easier to use a probe of some kind. I have taken a twenty-penny galvanized nail and chucked it in the electric drill, then spun it against the grinding wheel to reduce the nail head’s diameter enough so that it will easily pass thru a 30 caliber case neck. Then the pointy end is likewise ground flat and square. Now I have a probe that will enter 22 caliber cases with the small end and 30 caliber and up cases with the big end. I filed a series of marks on the shank so it is easy to tell when the charges in a loading block are all the same because the same mark is always at the case mouth.

     Checking the charges in 38 Special and larger straight cases is easy if you use a short piece of 3/8 inch wooden dowel which has been marked with suitable calibrations on the side. Drop it into the charged case, note the mark nearest the case mouth, and repeat for the rest of the cases. I also use the dowel to check the charged case in my Lee Loadmaster without removing the case from the press." John Bischoff

The Astounding Powder Measure Test!

     I tested eight mechanical powder measures: Lyman 55, Hornady Lock 'n Load Bench Rest, RCBS Competition, CH4D, Lee Perfect, Redding BR30, Harrell and Belding & Mull.

     In addition, tests were performed by John Alexander, Dave Goodrich, John Corney, Larry Talley and others. All the test data is in an EXCEL workbook. For a copy write joeb33050@yahoo.com.

     Five powders were used: SR4759, a tubular large-kernel powder; IMR4198, a smaller-kernel tubular powder; Unique, a flake powder; IMR4227, a very-small-very-short kernel tubular powder, and Accurate No. 9, a ball powder.

     The measures were tested for "Repeatability", the ability to throw charges of about the same weight;" Settle Down", to see if a lot of charges must be thrown before the measure settles down and throws consistent charges; "Head", to see if the height of powder in the measure affects the average charge weight-and to see if baffles are of value; and "Slope", to see if charge weight variation increases as the weight of charges is increased.

     The Belding & Mull measure was tested for "setting repeatability".

Repeatability:

     I measured the repeatability of a powder measure by calculating the standard deviation, (SD), of the weights of the second set of 30 charges (charges 31-60) thrown with the measure during the test. The first set of 30 charges lets the measure settle down. Or so I thought. 

     This table shows the SD, in grains of powder, of the measures and powders tested.

     All measures tested will dispense charges of AA#9 ball powder and IMR4227 small-kernel extruded powder with great repeatability.

     No measure tested will dispense charges of Unique, IMR4198 or SR4759 with equal repeatability.

What repeatability is required?

What seems to be important is the range of the powder charges, the highest weight of powder minus the lowest weight of powder in sets of charges.

     I suspect that the lower the range, the more accurately the set of loads will shoot. 

     We have the SD, and can use that and some math to get the range.

     Here's a table of ranges in grains, SDs and percentages. 

     See the bold numbers. With a SD or standard deviation of .15 grain, 10% of the time sets of 5 charges will have a range (highest weight minus lowest weight) of  .5 grain or MORE.

     ( The range for SD under .1 grain is low enough that thrown charges, without weighing, are acceptable. SD above .25 grain suggest that there's something wrong with the measure. Hence the entries shown with SDs from .1 grain to ,25 grain.)

     Unique has an average SD of .140 for all the measures tested. Five percent of the time a set of five charges or shots will have a range or spread of .5 or half a grain. For ten shots, five percent of the time the range will be .6 grains, for  twenty shots the range will be .7 grains.

     In my opinion, based on these results, no measure tested will dispense charges of big-kernel extruded powders or Unique  repeatably enough for bench rest match shooting or load testing. Weighed charges are required for any powder-powder measure combination that dispenses charges with a standard deviation above .1 grain.

     (For their help with the statistics, special thanks to Jeroen Hogema of The Netherlands; and Professor Steve Morrison, Chairman, and  Professor Kamran Dadkah, of the Economics Department at Northeastern University in Boston-where I went to school during the last ice age.)

     How to estimate the STDEV of any powder-powder measure combination

     Put the powder in the measure, throw twelve charges, returning each to the reservoir. Throw, weigh and record a minimum of thirty charges, returning each to the reservoir. Calculate the standard deviation using a (scientific or statistical) calculator or EXCEL or a friend or write in to the CBA Forum for assistance.

Dippers and repeatability

     Hoping that the Lee dipper would dispense charges of SR4759 and similar powders accurately, I worked with the 1.9 cc dipper for a while, then threw thirty charges using each of three techniques.

     The dipper method has a much larger STDEV than the measures-isn't the answer.

Settle Down:

     After the first six to ten charges are thrown there is no settling down or compacting of the charges, and charge weight does not increase. Thus, I no longer have to throw thirty to fifty charges before throwing keepers. Here's a chart showing the average weights of the first thirty(1-30)  charges thrown, and the second thirty(31-60). If there was a "settle down" effect, then we would expect to see the 31-60 weigh more than 1-30. We don't and there isn't.

Head

Powder height in the reservoir does not affect the average weight of charges thrown. There is no purpose served in placing baffles in powder measure reservoirs, or in putting funnels in the reservoirs. This is counter to advertising claims made for several measures.

Here's a chart showing the average weights of charges thrown with a lot of powder in the measure (31-60), and a little powder in the measure (61-90).

If powder height in the measure affected average charge weight, then we would expect to see heavier charges in 31-60 than in 61-90. We don't and it doesn't.

Slope

     I was surprised to find that charge weight variation increased as average charge weight increased. The more powder in a charge, the more variation. The standard deviation of charge weight varies from .001-.004 grains per grain of average charge weight; all depending on the powder and measure.

     Here is a table of slopes in SD grains, defined as change in SD over change in average charge weight. For example the SD of UNIQUE in the B&M measure, increases .003 grains per grain increase in charge weight. As the average charge weight goes up, the SD goes up. Heavy charges vary more than light charges.

Crunch

     Some powders crunch more than others going through the measure; some measures crunch with a given powder more than other measures.

     One of the techniques I've used is to throw back the crunchers because it is obvious that the non-crunchers are more consistent. Obvious, but not true. I can find no evidence that more crunching leads to less weight consistency; for a given powder. SR4759 is a big-time cruncher. I saw no connection between crunchy throws and weights. Non-crunchy weights were high or low or average, just like crunchy throws.

     The Lee Perfect measure doesn't crunch 99% of the time with any powder tested, including SR4759; yet it is no more repeatable than other measures. 

Bridging

     Sometimes powder doesn't come out of the measure on one operation, but lots of powder comes out on the next operation. The series of events varies, Ex: none-lots, or none-none-lots, or none-little-none-lots.

     I've seen this with SR4759 for years, never recorded what happened until recently. I have reports on bridging with surplus 4831, Red Dot?, 700X, 4831, 4831SC, 4064 and Trail Boss. My experience with bridging is only with SR4759, mostly because I rarely use the big-kernel extruded tubular powders.

     Bridging is caused by a too-small nozzle on the powder measure. Using the larger nozzle or drilling out the nozzle fixed the bridging.

     The way to absolutely eliminate bridging and the overcharges that may result is to weigh every charge or to use the B&M measure.

     I have come to suspect that some of the SEE (Secondary Explosion Effect) events may have been caused by bridging in the measure and overcharging. 

Micrometers

     The Lee, CH4D, Redding, RCBS and Hornady measures have micrometer adjustments. There were problems with all the micrometers except the Redding.

     I misread the RCBS micrometer twice during this testing, by one thimble revolution. I've had this same kind of error in the past with Lyman Super Targetspot telescopes. I think that the clearance-the difference in diameters of the thimble and body causes part of the problem. Looking at the micrometer and rotating the measure gives different views of any given line on the body, from visible to invisible, covered or uncovered by the thimble.

     The CH4D micrometer does not zero, bottom is at "251" on the barrel scale.

     The micrometer isn't aligned, zero on the barrel is at about 3.5 on the thimble.

     The Hornady Lock 'n Load Bench Rest micrometer barrel doesn't have a zero so you can't zero it, and the thimble doesn't align to register with the barrel markings.

     I now believe that one should never set any measure, micrometer or not, without checking the charge weight on a scale. It is just too easy to make a mistake setting the micrometer even if the notes and memory are in working order.

Knockers and Knocking

     During this testing I've had several reloaders explain their preferred knocking techniques, each of which, I was assured,  ensured accurate charges. Knocking is whacking the operating handle (or in the Lyman 55, the knocker) of the measure against the stop, top or bottom, a certain number of times, with a certain ferocity.

     I've used the Lyman 55 for many years, and it's the only measure tested that comes with a built in knocker. I have knocked religiously since 1960, and if I mis-knock or knock incorrectly, I throw the charge back in the reservoir. After getting the measure to settle down, I threw thirty charges with the Lyman 55, with and without the knocker, with each of the five powder charges. In every case the charges thrown were heavier with knocking; however there is little evidence that the knocker charges are more repeatable than the no-knocker charges. Here's the table.

     I think that consistency in operating any measure-including knocking- may increase charge repeatability; but I could not devise a test of consistency in operation. I know when I do something different when operating a powder measure. I suspect that most reloaders know when they do something different. Then it's time to return the charge to the reservoir.

Unique

     Unique doesn't dispense very repeatable through any measure. I wonder how much the charge weight variation has affected light rifle and handgun loads with this powder over the years. I've used Unique in everything from the Hornet to the 45/70, and in 357 and 44 Magnums. It's never the most accurate powder, but frequently comes in second or third. Maybe dribbling and weighing might pay off.

Powder Measure Testing Protocol

     (All calculations were done on samples of thirty charges. Thirty is the minimum sample size for reasonably accurate estimations of mean (average) and standard deviation. ) With a new measure, follow all cleaning and assembly instructions, then  run a pound of powder through the measure. Put powder in the measure, the object is to have a "lot" of powder in the measure. The Lee and Lyman 55 measures were filled almost full. The Hornady and CH4D measures have very large reservoirs, and had about three-quarters of a pound poured in.  Set the measure for the test charge, empty the measure, put the powder back in the measure, throw 60 charges, weigh each one, return each charge to the measure, record the weight.

     Pour most of the powder out of the measure, leaving about 1/2" of powder visible in the reservoir. The object is to have the measure almost empty. Throw twelve charges, returning each to the reservoir. Throw 30 charges, weigh each one, return each charge to the reservoir, record the weight. Set the measure for a "big" charge. Put a "lot" of powder in the reservoir, throw twelve charges and return them to the reservoir. Throw 30 charges, weigh each one, return the powder to the reservoir, record the weights.

     Here are the approximate weights of "test" and "big" charges that I used:

     All charges were weighed on my RCBS 10-10 scale.

The Lee Perfect measure

     I took the measure apart several times to clean out the working parts. The instructions mention that "Extremely fine powders may leak very slightly at this setting. This causes no harm" and advises us to tighten the Rotor Tension Adjustment screw. I tightened the screw as much as possible still allowing the handle to work reasonably. With Accurate #9, a ball powder, after throwing about 150 charges for the test, I swept up 38.4 grains of powder from the floor. The measure leaks like a sieve. (The next measure tested was the CH4D, after about 750 charges with five powders there was .6 grains of powder in the dustpan after sweeping.)

     While testing Unique, throwing the "big" charges, the first 21 charges weighed from 23.8 grains to 24.9 grains. Charge 22 weighed 27.5 grains, followed by 27.5, 27.5, 27.8, 27.7 grains, where I stopped.

     I checked the scale zero, took the measure apart and cleaned it, put it together and threw 30 "big" charges without a hitch.

     Something bad happened to the Lee measure while throwing the first set of Unique charges, bad enough to give me the willies. I don't think that the Lee Perfect measure meets the threshold requirements for a reasonable and safe powder measure.

Powder measure setting repeatability

     The question is:" If one repeatedly sets a micrometer powder measure to the same setting, how repeatable are the charges thrown at each setting".

     I chose to test with AA#9 because this ball powder flows through the measure very consistently. Set the measure, throw and weigh charges and we find that the charge weights vary little if at all. Since charges of this powder can be thrown very consistently, it is appropriate for testing the repeatability of settings of a powder measure.

     The measure was an old Belding and Mull with a micrometer charge tube-the only measure I had on hand then that had a micrometer feature. The micrometer has 25 divisions per revolution. The threaded plunger that the thimble is on is marked every five threads from "5" to "40".

     I put powder in the measure and fiddled around until I had developed a procedure.

• Loosen the thumb screw.

• Turn the thimble UP a few threads.

• Set the thimble to 10+0

• Throw a charge

• Put the charge in a 44 Magnum case.

• Weigh the charged case.

• Record the weight.

• Put the powder back in the measure.

• Turn the thimble DOWN a few threads.

• Throw a charge.....

• Continue, alternating between UP and DOWN.

• Always approach the final setting from below.

     (I put the charge in the 44 Magnum case and weighed the charged case because that procedure kept me, left handed and with a tremor, from spilling the powder on the way to the scale pan.)

     After thirty settings and charges, ALL the charged cases weighed 137.2 grains except the fifth, that weighed 137.1 grains.

     No powder measure has significantly better setting repeatability than this, none, including the Harrell. Because the error or variation here was essentially ZERO, and it don't get any better than that.

     The thimble on this charge tube can be set to 25 different settings per revolution. I set the measure in steps of five divisions, threw and weighed charges.

     From 9 00 to 11 00 there are 25 x 2 = 50 divisions, weight changed from 139.1 grains to 135.2 grains or 3.9 grains; so each division is 3.9/50 = .08 grains-eight tenths of a tenth of a grain.

     Then the micrometer can be set at finely divided settings, and the settings allow charges that are repeatable. Set it to 10 00 and get charged cases of 137.2 grains, (almost) every time. Set it to 9 01 and get charged cases of 137.28 grains, rounded to 137.3 grains, (almost) every time. No measure can do better, as long as the weight of charges of powder  is resolved no finer than .1 grain. Means, we might want 34.2 grains, or 34.3 grains, but we never want or need 34.25 grains.

     I suspect that any of the micrometer powder measures, including the Harrell, have setting repeatability with a standard deviation of well under .1 grains, which means that repeating this test will show that all or almost all of the charges weigh exactly the same.

     So if one was to sit down with some powders and a notebook, a table of micrometer settings/powder charge weights could be written. And that would be handy at the range, no scale would be needed to vary the charges of various powders, just "set it and forget it".

My opinion is that this is a dangerous practice because of the possibility of making an error in setting the micrometer.

The RCBS Chargemaster 1500

     This is an electronic scale attached to a motor-driven  powder dribbler. The scale can be removed and used alone. I tested this with SR4759 and believe that this machine will dispense powder charges with any powder that weigh within +/- .1 grain continuously.

     Any jiggling and more grains of powder fall in the pan. The Chargemaster must be put on a stable non-jiggling table or bench. This machine does a good job of measuring charges of big-kernel extruded powder, better than any mechanical measure tested.