Weighing each powder charge vs trusting a dispenser

S

Stats Shooter

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I have been doing some experiments with respect to my RCBS powder dispenser vs weighing Each powder charge for match rounds.

Whilst I am partially checking the accuracy of my Powder dispenser for a given powder shape, I am also necessarily checking charge volume vs weight's importance on consistency.

The reason for doing this test is just my own curiosity. A couple guys I shoot F-CLASS with (I shoot Open but they shoot TR) do not weigh their Powder charge. And these two guys regularly finish top 5 or better. And I have seen them in action at the reloading bench and know them well enough that they are telling the truth.

So I did my own experiment using powder I know meters well in loads I had already developed for my AR-10 and .223 Varmint rifle. The .223 powder is Hodgdon Benchmark and the .308 is IMR 4064.

Lake City brass for both cartridges, CCI BR-4/2 primers. And a 62 gr federal fusion bullet in .223, and 175 gr smk for .308.

In .223 I use 24.2 gr Benchmark for an average velocity of 2875 and in .308 I use 41.3 gr IMR 4064 for an average velocity of 2390.

I loaded 100 for each gun. 50 rounds where I weighed each powder charge, and 50 where I set the dispenser up and let it do its thing. I spot checked the weights of the thrown powder but didn't adjust anything, I just wanted to see how close it was. The biggest deviation was 0.2 gr in the .308. it may have been higher, but I didn't check each one.

I shot every single round through my Chroney, and took care to shoot the best groups I could at 200 yards.

The most interesting part of it all was the extreme spreads and SD's. The average velocities were within 4 fps in the .223 and 6 fps in the.308. That's small enough that the exact barrel temp and time of day could explain that, so I call it unremarkable. But the ES on the .223 of the thrown powder was 15fps and 27fps on the on the ones I weighed....and a few were up to 24 fps.
In the .308 the ES on my thrown powder was 11 fps, and the weighed powder loads were 19 fps.

The group sizes were not different between weighing and just dispensing at 200 yards.
But what this does is make me wonder if, with powders that meter well, if volume measurement is better than weight? My scale is a $300 gem pro Which I cross check with a beam scale

Anyway, I'm sure longer stick powders like Retumbo or H100 probably won't yield the same results. But it tells me that when loading for my ARs on my next progressive press I should get good results with the right powder choice.
 
Precision benchrest rifle shooters virtually all throw their powder charges. Harrel's powder measures seem to be very popular with them.
 
Trust what you see in real life.

Fifty round data points is pretty good. Federal Gold Medal match set many National records at Camp Perry out to 300 yards, the military teams use their own stuff at 600 yards, and we would have heard about it if Federal was paying employee’s to weigh charges.

I have not conducted as good a test as yours, but I shot thousands of rounds with thrown charges all the way out to 600 yards and can truthfully say, they all shot well. I will weigh maximum charges. Some powders, such as IMR 4064 and IMR 4350 are long grained and don’t throw worth a hoot, so I will weigh them. But I don’t know if it makes much of a difference in a big case. The 223 Remington is a small case so I would expect two tenth’s of a grain charge weight variations to have more of an effect than for a 308 case, but still, I have shot lots of tens and X’s with a 223, thrown charges, at 600 yards, so, maybe the affects are in the noise level at that distance.

I think good barrels, good bullets, and good bedding have a greater affect on accuracy than thrown charges.

It may be this weighed charge mania is advertising induced behavior. Reloading equipment manufacturers pay for ads in the print media. In print Gunwriters repeat the advertising claims (to keep the manufacturers happy) and we the shooting public believe what we are reading is factual, when the facts are, Gunwriters are shills and the articles they write are advertising. Can anyone name a Gunwriter besides Mike Venturino who shoots competitively? Based on the distances I see in gun articles, such as 7 yards, 15 yards, 25 yards, and three shot groups, the basic Gunwriter community can’t hold and shoot them straight. Plus, they have been Darwinian selected to repeat uncritically what they are told.
 
I have ZERO comment about your data, wasn't there, didn't see it, can't verify it, even if I was there is the crony & time of day to consider (daylight & sun position, clouds, etc.).

Some things to try when using a thrower,
Baffles! Keeps the throw from wondering when volume weight changes.
Washers/Weights on the powder column.

Some powders defy all laws of physics in certain droppers...
I have a Redding dropper that works GREAT with everything but Tight Group, can't throw a consistent charge of tight group to save it's life...
 
BR shooters rely on the high end powder throws such as the Harrel, and while they do pretty good with flake and spherical none do extruded very well

http://www.realguns.com/Commentary/comar63.htm

you sometimes have to wonder how much is natural variation, how much is shooter technique, and how much is equipment.

I am giving some serious consideration to outfitting the Hornady on my LNL to benchtop use for loading at the range this fall

here are some targets I shot at 100 yards Friday with a 1.4 grain varaition of IMR 4895 and some 34 grain dogtowns. The targets were hung with a landscape orientation.


http://imgur.com/a/ckBrp

http://imgur.com/a/yQ5AA

Now 8 groups are not enough to prove anything everything there could be natural variation, but still almost a grain and a half and no more than a half MOA difference in the horizontal and vertical on those groups
 
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For me a lot has to do with something I actually control.

With all the other variables, I know the powder is spot on.

Some comfort and a very iffy field as to what works and what does not and its far more likely to do with the trigger finger than anything (at least under 5/8)
 
For me a lot has to do with something I actually control
Click to expand...

I hear ya....it's why I weighed all my match and hunting rounds. But so far, in the years I have been trying to improve my accuracy, the biggest improvements have come from better case prep techniques and consistent bullet seating dies.

I know that weighing every charge is just "one more thing". But does it "actually" help? I mean sure it avoids a charge being way off
But you could avoid the "way off" charge by zeroing a digital scale to each cartridge, the charge it, and weigh again. This would be a little slower than just throwing, but not nearly as slow as trickling powder.
Then you would know you don't have any that are too far off and would speed up production a lot

And if my results hold, would be pretty accurate ammo
 
For me, it depends on the powder. For rifle rounds using rod powders like IMR 4064, for example, I weigh each throw, as those type of powders don't throw consistently enough for my liking.

Other ball type powders, or fine granulated powders, like Win 296, H110 or SMP 735, for example, throw very consistently. For these type of powders, only intermittent spot checking is needed.

Bayou
 
It sounds like those two F-class shooters described chose to spend their time practicing rather than hand-weighing each charge. Smart guys.
 
Some comfort and a very iffy field as to what works and what does not and its far more likely to do with the trigger finger than anything (at least under 5/8)
Click to expand...

I have to agree and of course once you get to a certain point on anything it becomes a game of diminishing returns. The closer you get to perfection the harder it becomes to progress farther


here is an excellent read where a writer who did some Monte Carlo simulations regarding muzzle velocity, SD, wind ability, ammo quality and natural variation.

http://precisionrifleblog.com/category/ballistics/how-much-does-it-matter/
 
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Congratulations on actually TESTING. You will go far validating things and spending time behind the trigger.
So many today follow the old Greek Idea that testing is not important, just thinking is all you need.
Everyone knows that weighed charges will be the best, so don't do any testing.
Oh, the benchrest crowd don't weigh? Well, those are old farts shooting at almost point blank range--nothing to learn from THEM.
Consistency is everything, even if one consistently increases head space or consistently makes the neck too thin so it is concentric.
OH, there is a no toy out that obviously can't hurt and may help, so I must buy at least one and NEVER consider doing any tests to see if there is any effect.
No need to test--these things are so OBVIOUSLY true.
 
here is an excellent read where a writer who did some Monte Carlo simulations regarding muzzle velocity, SD, wind ability, ammo quality and natural variation.
Click to expand...

Good read, but I think all the factors would increase in impact if the target sze was reduced to MOA or 1/2 moa. Going from.8 to .3 is necessary to be competitive if the x ring is .5 moa. But their results still stand.


Congratulations on actually TESTING
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I'm a natural skeptic and I do research for a living. While I don't discount supposed"expert" opinion, I won't take it to be gospel unless I can verify. I find that some of the "common internet knowledge" stuff is bs that has been repeated so many times people take it as fact.

Again I'm not saying weighing your charger is totally worthless, just that if a powder meters well, and since none of us has infinite time, there may be more impactful areas where I should focus to improve my performance.
 
I think it has to do with the powder measure . To just say Federal throws there charges so anyone with any powder measure should be gtg is a stretch imho . I have and use a Hornady powder measure and imo it sucks . When i throw IMR 4046 i get as much as a .7gr variance . Anything more the .3 in 308 is to much imo although I've not run any specific test . I have done enough load developements with 4064 to know .5gr has an effect on accuracy with my Savage model 10 .

Im actually looking to buy a better powder measure that will throw 4064 and the like better .
 
It is very commonly reported that the difference of maybe .2 grains up or down has almost no effect on the eventual violent, powerful burn and the pressure generated as far as whether it will be as consistent as a charge that was weighed down to the individual kernel. The difference in a fifty grain load will be insignificant in effect on accuracy when it is fired, just like a bullet that is about that same difference off.

Accuracy with a rifle is about mechanical stuff. Case sizes, case prep, good actions, good bullets, compatible load development, etc. i believe that using a cheap pair of dies with an off center stem will have a bigger effect.

I think that your best plan would be to find a few ball powders and see if any of them give you good results. They usually meter more consistently than any form of extruded.
 
If you think about a ladder test using .3gr increments, you look for the 3 most equal horizontally shots and use the charge from the middle of those. Hence you could be off by as much as +/- .3gr and not affect accuracy.

I still weigh each charge. More a peace of mind thing.
 
peace of mind? Some people approach it as an obsessive compulsivething. That's me. weigh bullets and charges, weigh cases, weigh primers...

Wonder what is wrong with those morons who buy factory ammo to use in matches.
 
When working up loads, I weigh every charge. When loading a quantity of ammo with a "something less than max load", I weigh every 5 (maybe 10) charges.
 
I think a lot of the obsessive compulsive thing is it's easy to go out and spend several hundred dollars on new equipment and devote hours in the shop weighing everything down to the last micrograin. Then we think we are really making progress toward that 200 15X when we would be better off just shooting the ammo concentrating on learning to read the wind and working on our shooting technique

One of the better long range shooters in our club uses an off the shelf Savage F/TR a modestly priced scope and Federal Gold Medal ammo. He is always in the top 3 or 4 at a match

metalgod - Im actually looking to buy a better powder measure that will throw 4064 and the like better .
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read this before dropping several hundred on a new throw

http://www.realguns.com/Commentary/comar63.htm

your Hornady will throw just as accurate or inaccurate a charge as a $300 dollar plus throw will. I am going to take Jeephammers advice and try some weights and powder baffles in mine to see if it helps
 
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I don't weight flake powder's but do everything else. I have heard that factory ammo is all done by volume. That would make sense to much volume. I am not a volume loader. I do enjoy loading, seldom ever load much over 100 rounds at a time. I think these turret press's and digital scales ect get's people into the hurry up mode. I have read a lot of guy" seem to load several hundred plus rounds at a time, That would get old for me too. Example here, when I'm working up loads I load, normally, four group's with three rounds in each. Load up 12 round's and off to shoot them. If I testing some hunting rounds, about ten rounds for five shot groups. Then if I like it, go home and load up 20 rds. If I had a 22 CF anymore, I'd load a hundred rds of so at a time. Sometime's just to generally fool with I get some SMK to see what a rifle will do. I only shoot my 6.5x06 at paper anymore and it get's a reg diet of 140 gr SMK. One 243 I use only 70 gr SMK's in. I could see if we were actually attacked by another country, loading up all I could, I don't see that happening in my life time. About 50 yrs and I still like reloading!
 
hounddawg, that was a very good and interesting read about those powder measures.
Thank you for putting that up. Now I know why I'm ok with my RCBS Uniflow. It works just fine with it's intended application.
 
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