Same powder, powder mixing?

[rustybayonet]

I have a lot of different cantainers of Unique some go back to the 1960's. I got them at stores or old reloaders that gave up on the hobby. My thought was to mix them all together and work a load up all over again.

The powders have been used on their own and work fine. Just wondering if anyone has done this before?

[RJH]

While many may advise against it, I have with no issues.  That said, when I did it, I was not loading to anywhere near max loads

[microham]

I would mix them well and then retest your loads to see if they still shoot the same as before. 

[noylj]

On one hand, folks say that there is no difference lot-to-lot in powder, so you don't have to work up from start loads and they just start at mid-range loads and then they'll tell you that if you add 40 grains of Bullseye lot# xyzzy-01-1998 to Bullseye lot# xyxxy-08-1999, you'll blow your gun up.

I look at most powders and I see any where from two to five different size kernels, so every time I get out a bottle of powder, I always shake it around as I walk from storage to the bench to be sure there is no 'settling.' So, if I add 40 grains to a 4 lb container, and shake it well, and then also shake it every time I go to the bench, exactly WHAT danger is there?

That being said, be sure to avoid the "all black bottles look the same" syndrome and always read the powder label to be sure you really do have what you think you have...

 

Edited June 30, 2017 by noylj

[kneelingatlas]

Is there a noticeable difference in velocity from batch to batch?

[rustybayonet]

On Friday, June 30, 2017 at 1:44 AM, kneelingatlas said:

Is there a noticeable difference in velocity from batch to batch?

I am not maxed on the charge, but they all seem to work the same with same charge. No chronograph. 

[Hi-Power Jack]

10 minutes ago, rustybayonet said:

 they all seem to work the same with same charge. No chronograph. 

 

Rusty asked a Great Question - but you can't answer it without a chrono.

 

They may all work "the same", but a chrono will tell you if they Really

work THE SAME.

[gtaylor07]

I ran into a lot change of Unique right before a major match, luckily I did a quick check to make sure it was the same because it definitely wasn't. Had about a 75 fps drop and had to get a new load worked up the week of the match lol.

 

Would have brought me sub major, and actually had a few already loaded I didn't have time to do more so I risked it and ran with a few of the light loads..... Not a good feeling having your first shot on the Chrono stage come in 60fps lower than power factor (must have also been a light drop, gotta love Unique), but at least the others were well above and averaged it fine.

 

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[anachronism]

And hopefully all of those partial canisters are indeed Unique. Using 50 year old pistol powder would concern me. Powder does break down over time.

[Hi-Power Jack]

2 hours ago, anachronism said:

  50 year old pistol powder would concern me. Powder does break down over time.

 

I'm still using powder I bought 50 years ago -   

[Steve RA]

1 pound can really lasts, doesn't it ???  

[Hi-Power Jack]

That was a 3 ounce sampler pack ....    

[jsg]

I've been known to mix older and newer powders (always same make and model) but never anything more than 2 years older than the current bottle. I also then go chrono about 10 rounds before loading any more. Doing this with HP-38 and Titegroup has not shown an issue yet and my loads have been consistent on the chrono. 

[Ken6PPC]

For the most part, mixing commercial grade powders (the kind available at your local gun store, or from most on-line suppliers) of the same brand and type is not likely to be much of an issue.  They formulate commercial grade powders to generate the same pressures for the same weight powder charges, to maintain consistency with published loading data. 

 

However, there IS some variation in VOLUME from lot to lot, and almost all pistol loading is done primarily by volume.  IOW, the same setting on your powder measure you used for the last lot might not throw the same WEIGHT as the last lot.  Powder loading rates can also change (although usually not less than a few decades).  

 

Here is what I do...  When starting a new lot, I check to see if the same VOLUMETRIC charge weighs the same as the last lot of that powder.  If it does, I then load some of the new lot and check that it performs the same as the old lot.  If both measurements are showing me there is little to no variation between the two lots, then I have no hesitation to mix the two lots. 

 

If they are different, well, at least now you know!  

 

One more thing.  If you move into something like military surplus, or non-canister grade powders, they sometimes are NOT close from one lot to another.  These products are produced in very large lots, and the military or professional loader develops loads based on the generated pressure (actually measured in a controlled lab) for each lot.  Most of us don't have that capability, so we almost have to treat each lot of surplus powder as a totally separate animal. 

 

Those surplus powders can be a great bargain, but there is a reason why they are!  They are not as easy to use as commercial powders.  Sometimes, a surplus powder can actually work for a specific purpose BETTER than what is available through the normal channels.  (T-32, T-322, and original IMR 8208 comes to mind...)  I NEVER mix those powders!  

[Steve RA]

4831 was a very good surplus powder, if you happened to be around when it was surplus.