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I do that, where there is a Tablespoon or so, of the older powder left.

I then roll the new cansiter or can to mix it well........Most of my loads are not at or near Max, so I see no reason to Back off 5%-10% either...........

With my 35Rem loads, (with a batch of NEW powder) my load is a bit above the published Max so I back off to a MAX loading, and load 4-6 rounds and chrono them to see if they match previous loads, while checking for sticky openings with that batch of NEW powder....

I've never had to reduce the load due to the new powder, but my hearing is shot too..............

SAFETY TIP: Because you're new to reloading, pay particular attention to powders with the same numbers, but different letters like H-4198 and IMR-4198..........they are NOT the same in sense!......be certain you are working with the correct data for the powder you are loading......


Tom
 

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I'm newish to reloading and was wondering if you can mix the last of a bottle with a new bottle of same powder.any words of wisdom would be greatly appreciated.
I don't do it unless they have the same lot number, which sometimes mine do because I usually buy in bulk.

But my grandpappy used to do it - although I think formulas and production methodology has changed so much over the years I would imagine the main thing is knowing from which decade the two different batches might have come from.

I would not mix a steel can formula with an ABS plastic can formula, if that makes sense. If the packaging is identical, you can probably get away with it IMHO regardless of the lot number.
 

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Cannister powders are remarkably consistent lot-to-lot.
I suspect no harm would come of it, but I do not mix the dregs of one can with the next; I just dump it on the garden or save it for firestarter.
 

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I do it all the time. If I am loading a large batch of cartridges and have several 1lb jugs from different lots I mix the powder in a bucket and pour it back in the jugs.
 

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In spite of what has been said, lot to lot differences can be sizable. I have seen a decrease of about 100fps with just the change from one lot # to another. This is why it is wise council to buy as much powder, all of one lot number, as possible once a sweet load is found.

However, be that as it may, use the powder from the first container down as far as possible then mixing the remainder with the new batch will have a very minimal impact.

Although few of us do so, it is also wise to back off a couple grains with a powder lot number change an retest back up to your previous load level. This is the safe and recommended way.

This is one of those do as I say and not as I do situations and most of us are still up and taking nourishment.

There are many gun to gun differences, but back a few issues, the Speer loading manual listed a load for the 300 Win. Mag that would get any velocity hounds blood running fast and hot, but in reality that load was HUNDREDS!!!, YES HUNDREDS, of feet per second off the pace of reality for most folk. Part of the difference was likely the test barrel as well as other issues, but I'd sure like to have tested some of the powder lot #!

Crusty Deary Ol'Coot
 

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Discussion Starter · #9 ·
Thank you all for your help. both cans were fairly new I used one almost completely and was going to start a new can , just wanted to make sure it was OK to mix.I dumped left over in new can and rolled it around my desk to mix .
 

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I've done it two ways:

One was add a very little remaining powder to a new lot, being very careful to completely mix it in with the new lot, the amount added being small enough to have a negligible affect on any potential burn rate change.

The second was as outlined earlier, put all I have of a single type (I.E. H4198) in container and completely mix into a homogenous lot.

I take static control measures if mixing in a second container. Any new lot gets re-worked up.
 

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CDOC, I was talking with a Hodgdon's rep today, and I commented on the industry standard of +/- 5% of control. He said that they specify +/- 3%, which would certainly be less variance. Nonetheless, if one is on the ragged edge, another couple of points may be get one into dangerous territory.

Your advise to back off is very wise.
 

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I guess I'm just not as persnickety as some. I have been mixing the dregs with a fresh container for about 40 years now and haven't had any problems. I know the lot number drill and it is probably important to bench rest shooters and others who compete but I can't really say that I have seen any differences with my bull barrel varmint rifles. My chronograph and the targets are very consistent from one can of powder to the next.
 

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If you are loading at or near a maximum charge, the +/- 5% powder density variation can be a big deal if using a volume drop powder feeder or measure. The density variations in same type powders are very real.

BB
 

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Along the same lines as switching powder lots with no regard, is the switching of brass with the same amount of concern - about zero - and this can also get you in deep do do.

Yes, I know that for the most part we all get away with it and have no visible negative results. However ------------

Some years back - 25 +/- - I was developing loads for a son's 30/06. We had about an hours drive to the range so wanted to make the trip worth the cost and effort.

Ran out of the Remington brass which was being used, so for the last two groups in the test series I went to the brass bucket for the needed brass.

I took care to sort the brass, same brand, same style head stamp, then trimmed to proper, "trim too length", and went ahead and finished the loading process.

Rather then using the 5 or so needed "odd" cases in just one of those last two groups, I seem to recall used 2 in the next to the last group and 3 in the final group.

The results make the point here. In the next to last test group, the "odd" brass opened the groups with maybe - ?? - some hint of pressure increase, while in the final group those "odd" cases gave excessive and very high pressures. So high in fact that one piece came out with a primer which looked like it had been riveted in place and that case stretched - in just one firing - to beyond the, "needs to be trimmed" length as well as throwing those shots waaaay out of the group.

I have never had this experience since and never before, but the point is it can happen and could really wreck your day or a fine rifle.

Today, with digital scales, we could weigh "odd" brass and likely avoid the potential problem by weeding out heavy/thick brass. How many of you weigh your brass? I'd guess few to none.

A better way is to keep you brass segregated by brand, lot number and times fired, at least for your typical center fire and high pressure rifle cartridges.

So, as I said earlier I have seen what I'd consider to be fairly large velocity changes with a change from one lot of powder to another, and have seen greatly excessive pressures caused by brass of an different manufacturing lot number, so it really does come back to being safe and no matter what or how we deal with the lot to lot differences in components, being aware that there is a proper and safe way and the way that most of us use and almost always get away with.

Be thankful that quality control is as good as it is, but don't bet you life on it.

Crusty Deary Ol'Coot
 

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I agree that Lot number is essenital more than anything. Not the same lot then no don't do it. With pisol powders you can use abvout evry bit of powder sense the carges are so small. But rifle that is another world you may have just enough left to not safely load then I would just burn it as mentions as in a fire starter. The .45-70 I inow takes 50 grains or more of smokeless and 70 grains by voume for the black stuff. Plus another thing once in awhile a lot# will be recalled. I don't recall on componets but in the service sometimes entire shipments would have to go back. Just my thoughts
 

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Along the same lines as switching powder lots with no regard, is the switching of brass with the same amount of concern - about zero - and this can also get you in deep do do.

Yes, I know that for the most part we all get away with it and have no visible negative results. However ------------

Some years back - 25 +/- - I was developing loads for a son's 30/06. We had about an hours drive to the range so wanted to make the trip worth the cost and effort.

Ran out of the Remington brass which was being used, so for the last two groups in the test series I went to the brass bucket for the needed brass.

I took care to sort the brass, same brand, same style head stamp, then trimmed to proper, "trim too length", and went ahead and finished the loading process.

Rather then using the 5 or so needed "odd" cases in just one of those last two groups, I seem to recall used 2 in the next to the last group and 3 in the final group.

The results make the point here. In the next to last test group, the "odd" brass opened the groups with maybe - ?? - some hint of pressure increase, while in the final group those "odd" cases gave excessive and very high pressures. So high in fact that one piece came out with a primer which looked like it had been riveted in place and that case stretched - in just one firing - to beyond the, "needs to be trimmed" length as well as throwing those shots waaaay out of the group.

I have never had this experience since and never before, but the point is it can happen and could really wreck your day or a fine rifle.

Today, with digital scales, we could weigh "odd" brass and likely avoid the potential problem by weeding out heavy/thick brass. How many of you weigh your brass? I'd guess few to none.

A better way is to keep you brass segregated by brand, lot number and times fired, at least for your typical center fire and high pressure rifle cartridges.

So, as I said earlier I have seen what I'd consider to be fairly large velocity changes with a change from one lot of powder to another, and have seen greatly excessive pressures caused by brass of an different manufacturing lot number, so it really does come back to being safe and no matter what or how we deal with the lot to lot differences in components, being aware that there is a proper and safe way and the way that most of us use and almost always get away with.

Be thankful that quality control is as good as it is, but don't bet you life on it.

Crusty Deary Ol'Coot
A very important point, this case capacity thing, especially with the different brands of .45-70.


I weigh cases on a digital scale, but not for a weight of the case, but rather tare the case off and weigh how much water the case holds.

I do this with at least 10 cases in a lot, get an average, and do peek at standard deviation to see how uniform that lot of cases is.
 

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A very important point, this case capacity thing, especially with the different brands of .45-70.


I weigh cases on a digital scale, but not for a weight of the case, but rather tare the case off and weigh how much water the case holds.

I do this with at least 10 cases in a lot, get an average, and do peek at standard deviation to see how uniform that lot of cases is.
With .45-70 and my .223 brass I weigh the brass so it is .1 grain plus or minus. Winchester brass is so hit and miss I refuse to buy it. Remington varies enough that I often get 51-55 shells in a bag that is supposed to have 50. Hornaday match brass so far every case has weighed the exact same but when marked 50 casings i seem to get 48 to a box. Every loaded .223 round I use weighs the exact same to the box I make and put it into. The .45-70 I sue pyrodex and measure by volume and still check every loaded round. Handgun brass has never been consistent enough to try for me. Just my .02
 
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