By Joe Cota
A quick preface before you read Joe Cota’s blog: Wow, we are up to three Joes on ExNotes…Joe Gresh, me, and now, Joe Cota. Joe Cota has contributed a few blogs to us previously (before we implemented our new writers program). When Joe most recently sent this in, I felt it was time to include him as one of our regulars, and with this blog, he is. Joe is one of the good guys. He is a professional geologist, an active off-road racer in Baja California, a handloader and bullet caster of 18 years, and an avid flintlock rifle and pistol shooter. Joe lives in the San Bernardino Mountains of Southern California. When not working or racing trucks and buggies in Mexico, Joe can be found fly fishing at his summer home on the Henry’s Fork River in eastern Idaho.
– Joe Berk
Written on Christmas Day, 2023
Merry Christmas to all 🎄❄️🎅!
A lot of you will be casting and handloading today, some with their new reloading equipment! Here’s something for your consideration that came up on another message board. Powder weight weenies will argue that all handloaders MUST unequivocally weigh each and every single powder charge to one tenth of a grain of powder or less. Some wildly claim that a half-grain (0.5-grain) of powder makes a 50 to 100 feet per second difference or more in rifle cartridge velocity while others often use this as flawed reasoning as back-up for claiming that volume-based powder dispensers, such as the Lee Auto Disc used on turret presses, are highly inaccurate and produce terrible and unacceptable ammunition. This could not be further from the truth! Let’s bust some reloading myths.
The variation that my ancient Lee Auto Disk throws is about 0.1 to 0.2 grain, depending on if I am using ball powders versus extruded powders. The photos below is what 0.5 grain of Hodgdon H4831 SC extruded rifle powder looks like. For reference, the variation in powder charges that my Lee Auto Disc throws is less than half of the 0.5 grain of H4831 shown in the photo.
So what does a half-grain of powder actually mean in terms of velocity in a typical big game hunting rifle? Let’s explore a real life example. I load .300 Weatherby Magnum ammunition with 168-grain bullets and H4831SC powder. Per the Hodgdon Reloading Data Center, the starting load is 74 grains (which provided 2,865 feet per second in their test rifle) and the maximum load is 81 grains (which provided 3107 feet per second in their rifle). That’s a 242 feet per second difference in velocity over a full 7-grain powder spread. Interpolating these results linearly (a 242 feet per second velocity difference over a 7-grain propellant spread) means that each additional grain of propellant over the minimum powder charger yields an additional 34 feet per second. Therefore, a half grain of powder would make only 17 feet per second difference in velocity! Everyone who uses a chronograph knows that 17 feet per second is typically only a fraction of the extreme velocity spread most rifles and rifle ammo produce.
What about pistol handloads? Take the .45 Colt, using a 255-grain cast lead bullet and Winchester W231 ball powder. The starting load is 5.1 grains (which provides 677 feet per second) and the maximum load is 6.9 grains (which provides 917 feet per second). Using the same methodology as the above rifle computations and comparisons, each 0.1 grain of W231 powder equates to only about 13 feet per second. Again, this is far less than the extreme spread one can expect in .45 Colt ammo.
Does case size matter? I believe it does, but not that much. Take the .223 Remington cartridge, for example, loading 55-grain Hornady bullets with Winchester 748 powder. Straight from the Hornady manual (the 7th Edition), 1 grain of powder between starting and max loads for this combination is 100 feet per second per grain of powder, or 10 feet per second for each 0.1 grain. And again, 10 feet per second is only a fraction of the extreme spread one could expect from perfectly identical powder charges.
So variations in powder volume does matter a little more in the smaller rifle cartridges, but not enough to make anyone steer clear of auto powder dispensers on turret presses versus individually weighing each charge. Richard Lee was right when he wrote in his Modern Reloading book that powder volume is more critical than weight and that one should periodically weigh a charge only as a double check for volume.
So there’s little justification for being a Tenth of a Grain Weight Weenie! Don’t be THAT guy who bashes turret press and powder dispenser users based on misconceptions posted by folks on the Internet.
Happy handloading and a prosperous new year to all!
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Joe,
Great article and thanks for writing it. I’d like to add a few comments.
• Yep, I suspect most ammo manufacturers dispense propellant by volume, not by weight.
• Dispensing by weight, especially with stick/rod powders, can be problematic if bridging in the dispenser occurs. One load is light, the next is heavy. I’ve seen this happen, even when tapping the dispenser. (Bridging is when the powder gets stuck in the feed channel leading into the cartridge case.)
• When shooting, I can sometimes feel a difference from round to round (one will feel hotter than another). I could be imagining the difference, but I don’t think so. I think I am feeling minor differences resulting from powder throw weight during the case charging process. But it could be bullet weight or bullet diameter.
• I don’t use a digital scale; I use an old RCBS scale beam scale I’ve had for more than 50 years. I can see as much as .3 to .4 grain per throw with stick powders when everything is working smoothly. Add powder bridging as described above and the difference would be much more.
• The linear interpolation (how much velocity gain versus powder weight gain) may not always be a good approach. I believe that as you approach case capacity, very small propellant weight increases can yield big velocity (and more importantly, pressure) increases.
• A lot of folks get hung up on velocity variation and attempt to make inferences about accuracy based on reducing velocity standard deviation. The only true accuracy measurement in my opinion is group size on target. Everything else is fluff.
• There’s an intangible associated with measuring every charge, and that’s shooter confidence. I do it for some of my load development efforts for that reason.
• What I think would be a meaningful assessment is comparing accuracy, say at 100 yards, for one group of ammo that had each charge weighed versus another that had all charges dispensed without weighing each one. One of these days I’ll get around to doing that. I’m not suggesting there would be an accuracy difference. I just don’t know. I may run that test myself and publish it in a future blog.
• Another meaningful assessment would be to dispense a number of charges with a manual powder dispense (i.e., not an electronic scale), say 30 or so, and then weigh each charge. It would be interesting to see the extreme spread and standard deviation of the dispensed charges to get a true feel for what the dispenser is providing.
• You mention case volume as a factor, and I agree. You can have fairly-wide powder weight differences in a .300 Weatherby and it won’t matter much. In a .22 Hornet, though, a small weight difference can make a huge pressure difference as you approach max loads. It’s one of two reasons I like Lil Gun in .22 Hornet…you can fill the case to the brim and it won’t put you in the danger zone, and Lil Gun at the upper range in that cartridge is very accurate.
As I know you know, there are many, many other factors affecting accuracy that would have to be controlled to really assess this issue. I’ve found that the biggest ones (once the most accurate powder charge has been determined) are (in decreasing significance) shooter ability, scope parallax, wind variability, bullet weight variability (especially in cast bullets), case neck tension (influenced by case neck hardness, crimp, case neck ID cleanliness, case neck thickness, case balance, etc.), case/bullet concentricity, and others. Sometimes there are others that come out of the blue. The scope mounting rib on Ruger No. 1 rifles can be a surprising source of accuracy degradation. It’s what makes it all interesting. All food for thought and a big part of what makes chasing accuracy so interesting.
I admire you with that .300 Weatherby. I load and shoot .300 Weatherby, too, but not very often. It is a brutal cartridge.
– Joe
Joe B.,
Those are all valid points. There are so many variables in shooting including powder and primer types, burn rate, neck tension. Add other factors in such as the bullet type, barrel twist, climatic conditions, and the shooter himself and there will always be room for more experimentation. My advice to all handloaders is to but a composition book and keep accurate records for all of your handloads by caliber and firearm developed for and tested in. For example, you may have three different revolvers of the same caliber where each works better with different loads. I load some pretty hefty .44 mag “bear loads” for my very strong single-action Ruger Super Blackhawk that I wouldn’t want to fire in my double-action Llama Super Commanche made in Spain. Things we should all keep in our records should include, but not be limited to are date loaded (very important!) type of brass, how many times reloaded, trim length, powder type and charge, primers, cartridge overall length, etc. Leave room in that same book for range testing, starting with date, climate (hot, cold, windy, elevation etc.), firearm type, velocity of 5 or 10 rounds and extreme velocity spread if you have a chronograph, felt recoil, distance to target, group size, bench rest or off-hand, etc. I usually cut the test group out from the target and paste it into my composition book.
And this is what makes handloading fun for many of us. But we must also realize and appreciate that there are probably more sportsmen who handload that don’t care anything about velocity, extreme spread, or pinpoint accuracy. For these hunters the most important thing is that their handloads are effective at taking the game they hunt, which is in a way the ultimate goal.
Thanks for your wise comments and hope to see you soon!
Joe C
Wow Joes, that was a great info article. I don’t reload but use to mix colorant for my plastic parts and a few granules one way or another didn’t make any difference either. Question: does a dirty barrel affect (like on a neglected 22 rifle) shots or feet per second more compared to clean barrel? I know it can affect jamming up a lot.
Rob,
I don’t know how much a dirty barrel affects velocity, but I believe that dirty barrels do reduce accuracy. But that is actually debated amongst some shooters and there is some “clean barrel” vs. “dirty barrel” disagreement. The thinking is that when rifling grooves get fouled with lead or copper residue, bullets can tend to “skip” along and not get the proper spin they need to stabilize, thereby reducing accuracy.
Here is my personal experience. I can fire my Marlin Model 60 .22 LR semiauto rifle for quite a long time (like all day at the range) before it loses accuracy, but it will start to jam when it gets too dirty. I have a Ruger Mark II semiauto pistol that is extremely accurate. I shoot it a lot, and after a few boxes of ammo, sometimes the groups will start to open up. When I notice this is starting to happen, I run a Bore Snake with solvent through the barrel and the group immediately tighten right up again. I always keep a bore snake in my range bag. And finally, I use Barnes and Hornady non-lead ammo in some of my hunting rifles. After cleaning the rifle, the first shot is off center just a bit (maybe an inch at 100 yds) from the next few shots. Many competition shooters take a first “free” shot they call a “fowling shot” before they start counting their shots.
My personal preference is to clean the gun after every range session for many reasons as dad taught us to do. “Never let the sun set on a dirty gun”
Take care,
Joe C
I have gone to using the LEE autodisc, or RCBS drop feeder, depending on which is more accurate charging for the ball, flattened ball, extruded, or flake powders. Sometimes I drop feed into the 50 year old RCBS beam scale pan and trickle the final few grains with the trickle feeder to the weight I need. So I guess I could be a part time weight weenie, lol. Sometimes straight out of the drop feeder and weigh every 10 rounds. Takes time but I am retired so not putting out as a factory speed loading. I dont hunt anymore so its pistol and rifle to the range with mostly common calibers in military rifle 30s, 45Auto, and 38, 357, and 44spcl/mag in revolvers. Also have gone to coated bullets from lead but still use some jacketed. 9mm and 223/556 have gotten cheaper for factory ammo in most cases when on sale than reloading due to component prices. A great past time. Thanks for the great reads!
Tony,
You are right, the accuracy of the Lee Auto Disk depends a lot on the powder type. Loading by weight over volume is probably the norm for most handloaders. I would guess there are probably more handloaders who use single stage presses and weigh out each charge than those who use turret presses and volumetric powder dispensers. I’ve weighed out charges many times myself, especially for rifle hunting ammo having large case volumes at close to maximum loads. For mass-producing ammo intended for volume shooting and plinking my preferred method is the Lee Turret with the Auto Disk powder measure. After setting up, I check the first five by weight, then every ten or so, and eventually about every 50 to 100 rounds after getting into my rhythm. I keep track of rounds loaded by eye-balling the number of a pack of 100 primers remaining in the feeder.
My general trust in volume over weigh at the medium load range probably began when I first started handloading. I used the old Lee Loaders and the powder dipper that comes with them. They worked great then and still do!
Some time I would like to hear more about your experience with powder coated bullets. I haven’t made that jump yet, still using Alox & beeswax stick lubes in an RCBS lubrisizer.
Thank you and have a great day
Joe C