Powder weight vs. volume

ApacheHunter · #1 01-11-2009, 12:26 PM

I realize that loading powder based on volume is more consistent than weight due to different environmental factors but how can you load measuring volume consistently? I am interested in tightening up my variables in my reloads. Is it worth the trouble?

Thanks fellas.

Catfish · #2 01-11-2009, 04:40 PM

If you have to ask the question the answer is no. The gain in accuracy is soo small that it will show up only in the most accurate bench guns. Unless you are shooting tight necked chambers, trunning neck and weighting cases there in about no chance you`ll ever find the difference. It is one of those thing that you can prove on paper easily, but is about impossible to prove in real life.

Adam Helmer · #3 01-11-2009, 06:54 PM

ApacheHunter,

Welcome to this Forum.

I am not sure I understand your question. I do not understand how you can load "based on volume" without weighing THAT charge. I suggest you get a good powder scale and adhere to 7,000 grains per pound and load powder according to a modern Reloading Handbook.

Adam

Rocky Raab · #4 01-12-2009, 08:14 PM

Actually, every powder measure is a volume device. So if you use a measure, you already DO load by volume. We customarily check the amount dispensed by weight because that's the most convenient measurement. But dippers, drum measures, or sliding chamber measures are all set to throw a volume, not a weight.

Adam Helmer · #5 01-12-2009, 09:40 PM

Rocky,

IDrum measures and dippers DO throw a VOLUME, BUT that is set by the weight specified in a reloading manual and CONFIRMED by a SCALE. Therefore NO Volume is properly dispensed until VERIFIED by a scale, especially when volumes are near Maximum charges.

I use a Lyman 55 Powder Measure (Volume) BUT ALL charges dispensed are adjusted and CONFIRMED by a Scale (Weight).

If you read the first sentence on the initial post in this thread, I cannot understand the thesis presented! He says, "loading powder based on volume is more consistent than weight" makes no sense to me and it is IMPOSSIBLE! If the volumes are consistent, then the weights are as well, as I see it. I will put my money on WEIGHT every time we seek consistency.

Adam

Rocky Raab · #6 01-13-2009, 10:10 AM

I agree, Adam. The fact that no two charges would ever "setttle" the same is the definitive counter-argument to volume being consistent.

I can demonstrate in a repeatable way three different volumes with the same charge.

Dumping the powder through a funnel will produce the least amount of settling, the most airspace and thus the tallest column of powder (in a test tube, for example).

"Swirling" the powder into the funnel so that it goes down with a "toilet bowl" effect drastically reduces the airspace and results in a shorter column using the exact same powder charge.

Swirling and vibrating the test tube, with something like an electric toothbrush, will result in almost no airspace and the shortest powder column possible.

So much for volume being the most consistent.

Adam Helmer · #7 01-13-2009, 11:54 AM

Rocky,

Well said! I totally agree with your presentation on the matter.

Adam

ApacheHunter · #8 01-13-2009, 09:52 PM

Well, maybe I've read some stuff wrong on some other forum boards and such. I "thought" that humidity and/or temperature would make the powder weigh more or less and you would actually be getting different amounts of powder based on environmental conditions.

That's why I mentioned volume being more consistent than weighing. Help me out here. Am I that far off the idea?

Thanks.

Rocky Raab · #9 01-14-2009, 09:27 AM

In a limited way, you are correct.

Powder can gain or lose a small amount of water from the air, and that will change its weight. But it is a VERY small factor.

If you empty your measure back into the sealed powder can (as you are supposed to do) it is simply not an issue.

ApacheHunter · #10 01-14-2009, 02:16 PM

I always put my powder back in original container and I wasn't sure about the difference it would all make. I guess that's what I was looking for.

Thanks for all the feedback.

Catfish · #11 01-14-2009, 04:16 PM

From what I have seen at the bench rest compations almost all of the competors load from a measure and never check the weight of the individual charges believeing that that they get more consistant loads from the measure. What Rocky said about the things that will change the weight of the voulume thrown are all true, but when you have a high quality measure mounted on a stable platform without bumping it around the loads should be more consistant than by weight. I might also add that with the high quality measures they use the vairation in the weight of the charge dropped in very small. 99% of my loading is on a Dillon 550 press and I set the powder measure on it and never check it untill I change loads. I load for several guns that shoot under 1/2 moa with these loads and a couple that will put them in the low 2`s. I will also add that I use ball powders 99% of the time. The Dillon powder measure is great, but not quite consistant enough for stick powder.

Adam Helmer · #12 01-14-2009, 05:50 PM

Catfish,

I think you got the cart ahead of the horse when you say, "benchrest folks load from a measure and do not check the loads on a scale."

I will bet those benchresters USED a scale to set their powder measures. I sure do and then weight check ever 15 or 20 powder measure drops on the scale. ALL measure drops need to be set by WEIGHT on a scale so you know where to set the measure. ANY VOLUME consists of WEIGHT; hopefully within specs and verified on a scale.

Adam