Powder Lot Variation

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What is the biggest powder lot variation y'all have seen? Or what is typical in y'all's experience?

I have seen as much as a 6% velocity difference with some powders like IMR 4350 and 4320. But for the most part the extreme powders from Hodgdon, which is what I use, is generally within 1-2%.

I'm just curious what others have found.
 
Unique.

With one lot, I did a work up for 357 Magnum and 125gn JHP's. I worked up to 9.7 grains - the Speer #14 max with no problems. I settled on 9.2 grains as the "set" round, allowing for a good deal of "headroom" (with Unique, I like to leave a good deal of headroom because it meters crummy). 1315 f/s through a 3" bbl. Loaded n shot lots of them at 9.2.

The next lot of Unique, that same 9.2 grains delivered very flat primers and difficult case extraction. The day this happened I was without my chronograph, so I don't know the velocity. I pulled the remainder - 32 rounds. I then loaded a new small batch at 9.2, and . . . flattened primers again. No more of that.

I haven't loaded additional 357/125's with this lot of Unique. I'll probably load a few at 8.8 grains, and see how it goes.

Coincidentally, I started a load work up with this same lot today - 45 ACP / 230 JHP. Just loaded them; haven't shot them - but that's for another post as a 'range report' after the work up is complete.

I'm not a fan of Unique anyway. I have 1 3/4 #'s and can't wait to get rid of it. In fact, the last unopened # (same lot as the opened one) may get donated to my range club to be raffled off. But a discussion about Unique is for another post too :D.
 
I like unique for 44 spcl, old fashioned I guess, on somethings. have good luck metering in Lee auto power. Which surprises me. For shape. Not sure it would in RCBS, with different motion.

IMR 4350 crunches on old RCBS, better on new. A case where being old fashioned is bad.
 
Most of the lot variation I speak of are rounds I trickled.

In my RCBS powder thrower, with long stick poweder, I have seen H1000 vary by 1 gr. i.e. set it at 78 and get 77.5-78.5 gr. To me that is a whole lot of difference considering I do load workups in 1/2% increments.

However powders I use in my handguns like HS-6, CFE Pistol, meters great, like +/- .1 gr. Rifle powder I use to make volume ammo runs such as Benchmark meters great also . But, if I'm trickling such as hunting loads or match loads, I don't care how it meters.

But meter ability isn't the tangent I meant to go down.

I do an abbreviated load workup with new lots of powder, essentially dropping the charge 3% or so depending on how close to MAP I am and compare the velocity to my other data. If it is much more or less, I will adjust accordingly so I don't sit there and shoot up rounds knowing I'm not in the old accuracy window.

However, over the last few years I have been buying powder by the 8# jug to avoid this scenario.
 
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