Need an answer to a simple question

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Mk-211 said:
I'm willing to bet that they have less than a pound leftover when they finish a run.

Waste isn't something companies want, costs them money to toss product.
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Depends on the machine, the size of the hopper, and how full the hopper needs to be to maintain .1 accuracy maybe? A 2lb hopper might need 1lb to remain in it to keep things at .1 grains. If your loading say...10K rounds of "X", at 10 grains ea of powder, and you got shipped from your OEM supplier 10lbs in one lot, and 10 lbs in another lot to fill a 20lb order....you're potentially dumping 2 lbs of powder, unless you tail those lots. The math is pretty simple there. Now, if you're doing boutique ammo, maybe for the long distance game.....that's another story....but you may be charging 5...8 bucks per round for precistion ammunition, in which case tossing some powder is the cost of doing business.
 
Post number 20 and post number 22 bring up some good points:

luzyfuerza said:
Powders can be safely returned from the bench to the containers they originally came from. No question there.

However, I would caution that just because two powder jugs have the same powder name doesn't mean that their contents can be safely mixed. If "tailing" as @EricBu suggests, I suggest that lot numbers on the two containers should also match.

Manufacturers warn against mixing powders. For example, a 2009 Reloader's Guide from Alliant includes this warning: "...do not attempt to blend salvaged powder with new powder or attempt to blend two types of powder to make a 'custom' blend."

Canister powders are themselves mixtures of various feedstocks. There is no way for handloaders to know how mixing powder from two lots of Bullseye, for example, might affect the pressures (for example) produced by the resulting mixture of two mixtures.



Even though most reloaders can't measure pressures, we CAN measure variations in velocities produced by different lots of the same name of powder. And perhaps those velocity variations from lot to lot might provide interesting information. So, some time ago, I decided to compare velocities produced by two lots of Bullseye. Here's what I found:

My recipe was for 9x19, using range brass, 115 grain Extreme CPRN, OAL 1.130", CCI 500 primers, loaded on an XL650 using the same adjustments, shot in an XD service model with a 4" barrel, on the same cold February day, with the same ambient conditions, over the same chronograph, etc.

luzyfuerza

The velocity difference was 51 fps, or 4.7%. This is more than three times the standard deviation for each load. Even with the low number of samples, I think that this difference is likely to be real.

I wanted to keep the velocity for the rounds loaded with Bullseye lot B similar to those loaded with Bullseye lot A, so I dropped the charge weight using the lot B powder down to 4.0 grains (a 7% reduction). This lower charge weight produced 1090 fps, which is just what I wanted.

This is one reason why I don't mix powders from different lots, even if they have the same powder name on the container.
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kennedy said:
I also do not mix from different lots, I use Universal and some lots are denser then others and have to adjust my load to compensate.
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A little off the topic but powders have a VMD (Volume Metered Density) which is what the ever popular powder dippers are based on. Lee publishes VMD charts assigning a VMD to different powders. I haven't a clue how accurate this is but my own understanding is that powder manufacturers allow a 16% deviation lot to lot. For the truly curious at heart calculating a powder VMD is pretty simple.

CC setting (powder measure setting) / Weight of the sample in grains = VMD (volume in cc’s for 1 grain)

So fill a known volume like a dipper for example. Weigh the powder and divide the actual powder weight into the volume. This gives you the VMD for that lot. Using the example posted by luzyfuerza above.
4.3 grains of Bullseye lot A produced: 1087 fps, SD=16, N=8
4.3 grains of Bullseye lot B produced: 1138 fps, SD=15, N=8

Bullseye according to Lee has a VMD of 0.1064. My current open container (1.0 Lb) works out to be close at 0.1061. While close, not quite as expected and I have seen some large deviations over the years.

For what it's worth or not worth....
Ron
 
EricBu said:
I'm curious if you guys think commercial manufacturers toss powder when they finish one lot and start a new one? Or if they maybe tail lots?
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Note that a commercial manufacturer should have a level of competence and ability to test the pressure and performance of their final product that is beyond the capabilities of most home reloaders. Encouraging those who might not have these same capabilities to follow commercial practices might not be sound advice.

Also, I didn't see anyone above suggest that throwing away a powder remainder was necessary.
 
Being that Alliant and General Dynamics are the only two canister powder manufacturers in the U.S....

With modern manufacturing, I still don't see them tossing much. It's metered down to the nth degree for military loading and then the rest to the civilian market.
 
igotta40 said:
I’ve read and heard one should not return powder to a container. Why not?
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That is news to me and I started reloading in the '60's. That doesn't mean that I am an expert on reloading but I have a fair amount of experience and read the how-to in several manuals before trying my hand at it. My method is pretty simple. I only have one container of powder on my bench when loading and set it right behind the PM in case I have to take an unforseen break and it's easy to see what powder is in the measure. When I finish a loading session the PM is emptied back into that can. When that can is empty it goes in the trash and I open a new can and repeat the process. When I finish the can goes back on the shelf and is used from until it is gone. NO mixing. This is probably too much information but it's the way I do reloading that I consider safe.
 
luzyfuerza said:
Note that a commercial manufacturer should have a level of competence and ability to test the pressure and performance of their final product that is beyond the capabilities of most home reloaders. Encouraging those who might not have these same capabilities to follow commercial practices might not be sound advice.

Also, I didn't see anyone above suggest that throwing away a powder remainder was necessary.
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Hmmm. Absolutely no difference between small manufacturers, custom loaders, boutique ammo makers and reloaders other than scale and new brass. But you do you, long as folks understand that there is no reason not to cross lots from a chemistry and material perspective. And yes, your suggestion amounted to throwing powder out, as you didn't limit your opinion to single stage loading, and individual weighing of charges, and not crossing lots is certainly easily achieved in that scenario. Since at least half of all reloaders today use a volumetric measure, and since most of the most common ones in use require the hopper to be 1/2 full to maintain consistency, since most buy their powder in 1lb jugs, when they can find it, and usually 1 at a time, and most hoppers hold a lb.... you're basically telling half the users on here to throw away a 1/2 of every jug in the name of some vague belief that its a safety issue. When in fact no such safety issue exists.
 
Reloadron said:
Post number 20 and post number 22 bring up some good points:






A little off the topic but powders have a VMD (Volume Metered Density) which is what the ever popular powder dippers are based on. Lee publishes VMD charts assigning a VMD to different powders. I haven't a clue how accurate this is but my own understanding is that powder manufacturers allow a 16% deviation lot to lot. For the truly curious at heart calculating a powder VMD is pretty simple.

CC setting (powder measure setting) / Weight of the sample in grains = VMD (volume in cc’s for 1 grain)

So fill a known volume like a dipper for example. Weigh the powder and divide the actual powder weight into the volume. This gives you the VMD for that lot. Using the example posted by luzyfuerza above.
4.3 grains of Bullseye lot A produced: 1087 fps, SD=16, N=8
4.3 grains of Bullseye lot B produced: 1138 fps, SD=15, N=8

Bullseye according to Lee has a VMD of 0.1064. My current open container (1.0 Lb) works out to be close at 0.1061. While close, not quite as expected and I have seen some large deviations over the years.

For what it's worth or not worth....
Ron
Click to expand...
Yup. I just got done comparing an old lot of Accurate No.2 (VMD 0.0838) to a new lot (VMD 0.0962) both weighed in at 3.1gr under the same 148gr. BNWC, R-P cases and Federal SPP primers. The new, fluffier, less-dense No.2 is only about 50fps slower (AVG of 24 rnds) than the old lot from the same 6" Colt's Official Police. That difference isn't much as long as you're on the low end of pressure.

Depends on the use and product. I'd be a little cautious about mixing lots of Blue Dot for max. loads in a 10mm. Blue Dot is already temperamental.
 
igotta40 said:
I’ve read and heard one should not return powder to a container. Why not?
Click to expand...

Sounds like dumb advice to me. Just exercise caution that you are returning it to the correct container. As far as dumping the dregs from one container to a new one, I do that too. Again, be sure its the correct container.

Forgetting to close the drain on a Chargemaster is like a right of passage! :( I've only done it once, but once was enough.
 
I don’t pour out of a jug, I pour from the jug into an empty 1 pound bottle. I label that bottle with type and lot number. Then I use that. Only 1 on the bench at a time. And even then, I label my powder measure both as to powder and what it’s set for, so if for some reason I take a break there is no confusion.
 
lightman said:
Sounds like dumb advice to me. Just exercise caution that you are returning it to the correct container. As far as dumping the dregs from one container to a new one, I do that too. Again, be sure its the correct container.

Forgetting to close the drain on a Chargemaster is like a right of passage! :( I've only done it once, but once was enough.
Click to expand...

Hahahaha! Yes, should be step one in the Chargemaster user manual. "Pour a jug of powder on your floor now and get it over with".
 
Probably came from someone who has worked in a chemical laboratory. Chemists take no chance of contaminating the reagents. Different problem than realoading. Not the right solution for reloading powder. Just be sure you put it back into the correct container
 
I've read in a few places that powder manufacturers keep lot to lot variations to under 4% (long ago and can't remember source) So, I believe that if I return 1/4 ounce to a new 1 lb bottle the change in overall performance of the new bottle would be infinitesimal...
 
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