Home Forums Reloading Big Game Rifles Powder Charges: Weighing vs Throwing

Well, I think Bushrat said it best:







Well said sir..................

4,231...4,232...4,233...



Huh, what? Weighing or throwing? Geez, you guys just slop any ol' charge in your cases and hope they shoot, right?



Me, I count individual granules of powder.



Got a load worked up for a .300 RUM, it only takes about 35 minutes to charge each case.



Four thousand, two hundred and - aw, shoot, where was I?



1, 2, 3, 4, 5...





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Still using the same RCBS Uniflow measure I bought circa 1976. For the long IMR powders - 4350, 4831 - I weigh every charge, for shorter stick powders like IMR-4895 or most of the Reloder series and all ball powders I just throw the charge.

I weigh my rifle loads where .1gr in 50 - 60 grs amounts to squat, and throw my handgun loads, living with a possible couple tenths variation in 5-10 gr loads <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />
I`ve never said I know what I`m doing , just that I do it.......works for me though.

I weigh and trickle all of my powder charges as it is not a big deal if you are only loading 20 or so big game rounds. if I am loading 60 grains, my acceptable range is 59.9-60.1. I do not know if it makes much of a difference but it is too easy not to do for a box of ammo.

I had one gun that gave me a good lesson in how very precise powder charges aren't always important. It was a contender 14" pistol, in a wildcat chambering that necked the 30/30 down to 6.5mm and sharpened the shoulder to as I recall 38 degrees. Anyhow, that setup should be inacurate right? Break open action, crummy thutty thutty brass, and a pistol to boot. Well, at the time all I had was a lee powder measure, and of RL 15, Varget, VV N550 and H-4350, 4350 would shoot twice as well as the other powders.

I don't recall the exact powder charge, somewhere around 35-36 gr, but the lee measure would very charges by upwards of a grain. Despite the varrying charges from the Lee measure, that gun would consistantly shoot 3 shot 100 yd groups of 1/2".

Guys,



Between talking with Mtn Hunter and Bxroads, I think I have figured out what all the fuss was about.



I have only used the Harrell powder measure. The Harrell is marked in gradations from zero to 200 in 1/2 "click" increments. The powder capacity setting knob is a cylinder that�s about an inch in diameter and is very easy to set and to read.



If my setting last week at the range was 120 clicks, all I have to do is turn the knob until it reads 120 again and start throwing--it will throw the same charge. The Harrell is very consistent and repeatable. However, if it didn't have any numbers marked, then I agree that you'd want to verify at least the first setting, if not each setting, with a scale.



I agree with Mtn Hunter that if you use a powder measure that does not have numbered gradations, then you are indeed reloading blind if you don't verify your measure's settings with a scale each time you make a change.



When I said I didn't use a scale during load development, it makes sense many would call that dangerous, given a powder measure without numbered gradations and/or not checking to see what one's measure actually throws.



Here is what I do. Each time I use a new powder, I throw 10 charges into my scale. I do this at home. I see how much powder it throws and what the variation is. I write this down. H-4350 throws .57 grains per numbered gradation. "Numbered gradation" is what I mean by "click". To be on the conservative side, I use .6 grains per click. I then find a minimum load in grains from the manual, and divide that by .6. IE, 50 grains of powder equals 83 "clicks". Then I set my Harrell on 83 clicks and start loading.



To me, the above doesn't constitute using a scale for load development because I don't take it to the range with me. However, I am using a scale to check my measure for each type of powder I use, I just do that at home.



I hope this all makes more sense...........

About the only way I'll believe it is if I can try it myself. So send me a Harrell and let me give it a whirl <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Roads

Next time I will make sure I am very clear on how my measure is set up. Though some of this stuff is better "shown" than "told"................

Here is a link to Harrell. I have the premium, but the picture on the home page gives the best view of how it's gradations are marked.

http://www.harrellsprec.com/index.html

I too use the Throw vice weigh method. I keep a reloading diary that lists the bullet weight and make, the setting for my Redding powder thrower (all though I check it at the begining of each session and note any discrenpicies), the brass and primer used where I got the starting load, the date, the results and chronograph results as well as any think else that runs through my mind while reloading.

I also include the trim length and setting for my wilson trimmer.

Harrell's is reputed to be one of the most consistent measures. I haven't had the spare bucks to get one to try. About the only suggestion that I can make is to try Tim Johnson's Quick Measure to see whether it's more consistent than Harrell's measure.

All the best tests that I've heard-of agree that carefully thrown charges � even with second-rate measures � produce more-consistent groups than carefully weighed charges. I'm not satisfied that the ultimate comparison has been made, so there may be more light out there waiting to be lit.

I think this ***may*** be true when comparing charges from different lots of powder, but I find it hard to believe when comparing charges thrown using the SAME lot of powder.

My RCBS Uniflow is extremely consistent when throwing ball powder (+/- 0.1g), very consistent when throwing small kernel extruded powder (+/- 0.5g), but may vary by a total of 2.0g or more when thowing large extruded powder like IMR4831 (most are more consistent than that, but you have to work with Extreme Spread and Standard Deviation in charge weights). From my load development work, which I do in 0.5g increments, I can tell you there is no way that thrown charges that vary by 2.0g will be as consistent as weighed charges that vary +/- 0.0g.

Some of my most consistent loads have been for my Marlin .45-70 and my buddy's Marlin .30-30. Part of the reason may be because we crimp the loads and the crimp helps ensure a more consistent ignition, but shooting 5-shot strings will often yield Extreme Spreads under 5fps, with Standard Deviations as low as 1.7fps. Hand-weighed charges, of course.

Does it make a big difference for hunting purposes? I think it would be hard to build a case for that argument. But still, I throw my ball powders and weigh my extruded powders.

I don't think that I've ever run across any claim that thrown charges are more consistent in weight and don't remember any claim of more-consistent velocities than with weighed charges � only that their groups are more consistent. I thought that was what I said.

Jim I not only count each granule of powder I also weigh each one and anydifference in a granual varining more than 2 percent gets thrown out. Some day soon I will get that second round loaded then look out we is gonna be talking some kinda accuracy. <img src="/ubbthreads/images/graemlins/help.gif" alt="" />

Bullwnkl.

Way to go, 'Winky! (Long way to go.)


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A two round group don't count. Were it me I'd keep going till I at least had three! Like Ken said, "You got a long way to go!" <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />
We're cheering you on. We'll expect a range report in 2006. That's not toooo soon, is it??? <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />


I drop close to weight, and then trickle up. Works for me.

I think it was in Hatcher's Notebook (???) where Hatcher (or someone) described his efforts to improve the arsenal National Match loads by weighing the powder charges, which at the time used 4064. Unfortunately, and perhaps intuitively paradoxically, the weighed charges consistently produced LESS accuracy than the machine thrown volume charges. He repeated the experiment several times, and always got the same result, too, so it wasn't a statistical fluke. He checked all the loading equipment and techniques, and could find nothing to slant the tests one way or the other.

He said he really couldn't fathom the reason for this, unless it was a factor of how the powder charges ignited. Perhaps, he theorized, the bulkier thrown charges left just enough more air space between the powder granules that the flash from the primers penetrated the charge better, producing more uniform ignition. He firmly stated this was just a theory, and wasn't sure it was THE reason, but it was all he could think of, and I suspect he was correct, though I too can offer no real proof. It just sounds "good," since ignition of the charge is or can be a very significant factor in accuracy.

I think the only real answer will have to come from actual shooting of the load with both weighed and thrown charges. If the thrown charges are more accurate, do we REALLY need to know just exactly WHY??? the main thing is finding THE load, right?

Just because Hatcher's experiments with the National Match loads shot better with thrown charges don't necessarily mean your charges with some other extruded powder will follow suit, of course, and that's why one needs to try the thrown vs. weighed charges in one's own gun. Without this, we're just speculating, and if one shoots better than the other, just use it, and maybe one day someone will figure out the reason you're getting the results you get with your gun.

Mysteries like this aren't really a "bad" thing. Surely makes us re-think what we do sometimes, doesn't it?

Wanted to see if this thread could be brought to life 'cause I have some comments to be made.


Big Al

Earlier in this thread I posted that maybe I should convert to ball powders and be done with it. Well I haven't done that, but since the majority of my loading lately has been for 308 Win., 300 and 250 Savage my main powders have been IMR & H4895, Varget, IMR4320 and RL-15. With these small kernel powders I find that I can throw charges to +/- 0.2 grains. In fact when I was setting up the measure yesterday to throw charges of 41.5 grains of H4895 for my 300 Savage, I was able to hold them to +/- 0.1 grains most of the time. I think this tolerance is way tighter than anything I need to worry about, so I'm content to throw and go.

BTW, I'm using a plain old Uniflow with one of those bent metal powder baffles dropped into the bottom of the hopper being the only modification.

mathman

The question is very easy to answer, if you are willing to do a little bit of basic math.

The 223 is fairly sensitive to variation in charge weight. Very roughly, a grain of powder is about 100 fps, vs. 50-65 in larger cases. So use the 223 as a near worst case example.

Standard deviation is the most sophisticated measure of variation available.

If I'm not being terribly fussy, the standard deviation of my handloads, with individually weighed poweder charges, is about 25 fps, normally distributed.

Using Varget, and a $23 Lee Perfect Powder Measure, the standard deviation of powder weights is .11 grains.

A grain of powder is about 100 fps, so the "thrown" charges have a standard deviation of 11 fps.

BUT:

Standard deviations do not add linearly. They add by the square root of the sum of the squares. Compared with 25 fps for individually hand weighed, the standard deviation for "thrown" charges will be

(25^2 + 11^2)^.5 = 27.31 fps.

So assuming that I can perfectly hand measure charges, the penalty for using the measure is an increase from 25 to 27.31 fps. In larger cartridges, it makes less difference than that.

You would have to shoot many hundreds of rounds to statistically detect that a change this small even existed at all.