Is there a variation by lot number for powder

[BGD]

Is there enough variation in the same powder from different lot numbers that you need to reduce your charge? Do you need to work up the load again if you buy a new pound of powder?

Thanks,

 

[USSR]

If you're on the bleeding edge as far as velocity/pressure goes with your original load, then yes, reduce your charge weight and work up. Otherwise, no.

Don

 

[Fishslayer]

I load on a Lee Classic Turret with Auto Disc. I check weight/volume when I start a new pound. So far I haven't seen any really noticable difference from one bottle to the next. IIRC the allowed variance is 10% but I could be wrong. My usual powders are Green Dot, Bullseye and 2400.

Doesn't take long to check a new batch and helps keep Mr. Murphy at bay.

I generally don't load anything really hot. If I did I would probably go ahead & work back up when starting a new pound. If I actually did that I would probably start buying 8# kegs.

 

[USSR]

IIRC the allowed variance is 10% but I could be wrong.

I believe the allowed variance is 3%, but they usually hold it to much less.

Don

 

[Walkalong]

My new RL-15 is slightly denser than the one pound jug I had. I adjusted the powder drop to get my new charge weight and the new lot shot superbly. Without more testing, it appeared to give similar velocities. So not enough difference to matter. I know by the velocity I got for 10 shots I am not over pressure.

The correct answer is to back off and test, before going back to your load if it is at or around max. I was, and I did. I dropped .2 Grs to test. I was going to back off anyway, and it paid off all around. I am now .5 Grs lower than the highest I went.

The only thing I did wrong was buy 5 Lbs instead of 10 pounds.

 

[Peter M. Eick]

YES!

In certain powders. I always rework my loads of SR4756 over the chrono. I don't sweat Unique differences. I am cautious with Blue Dot loads and normally will work them up over the Chrono.

Some powders vary. Some don't (as much).

 

[gamestalker]

Since I usually run worked up to max. loads, I will often reduce and do a short band re-work. But for mid range loads that are not on the max. end, I don't personally reduce and work back up.

GS

 

[gamestalker]

Oh, and provided all other particulars haven't changed, bullets, primers, or the weapon I developed them in.

GS

 

[buck460XVR]

If you're on the bleeding edge as far as velocity/pressure goes with your original load, then yes, reduce your charge weight and work up. Otherwise, no.

Don

Same here. Another thing I do is whenever I'm half way thru a jug of powder be it a 1# or 4#, is I open another and mix the two. This is an old painters trick that reduces any variance between the lots to less than what it would have been otherwise. With most powders I use, I see no more difference in velocity and/or accuracy between lots of powder than I see between different batches I load at different times. Very little. YEMV.

 

[45lcshooter]

If your trying to shoot a pencil point at 1000yrds, then yes I would work up new loads for the new lot powder. But if your just hunting or target shooting, it won't make a difference.

I'm still using powder from the 80's and those lot numbers are long gone, I still shoot through the same hole with the powder from the 80's and the powder I picked up last weekend.

 

[Slamfire]

I always had troubles with Accurate Arms powders. AA would change manufacturer's, loads developed with Chinese made powders would blow primers with Czechoslovakian powder using the same powder charge. Chinese powder was actually very good, my Chinese made AA2495 was excellent.

Accurate Arms told me the industry standard between lots is 10%. If you are max with a powder at the low end of that 10% then you buy a lot that is at the high end of that 10%, you are going to blow primers.

 

[Walkalong]

Yep, better rework AA #5 loads.

 

[FROGO207]

I agree with Peter M. Eick. I always buy in large lots so the workup will last for a while and I ultimately waste less components. There usually seems to be a very small change lot to lot but if I always expect this then the chances are I would be wrong that one time I don't bother. Better safe than sorry with anything reloading is my motto.

 

[Hondo 60]

I do as buck460XVR said in post #9.

whenever I'm half way thru a jug of powder be it a 1# or 4#, is I open another and mix the two. This is an old painters trick that reduces any variance between the lots to less than what it would have been otherwise. With most powders I use, I see no more difference in velocity and/or accuracy between lots of powder than I see between different batches I load at different times.

If I reworked at every new lot number, I'd never have a go-to load.
I'm not rich, so I can't afford to buy powder in 8# jugs, but $20 a month or every 2 months is much more palatable.

 

[ljnowell]

Yep, better rework AA #5 loads.

I love my AA powders, I really think that when talking fast powders AA#2 is the most versatile and definately the best metering powder out there. However, I always buy in the biggest amount that I can. I do not trust loads from lot to lot of it. The last time I bought Powder Valley had 5lb jugs of it. I called and asked them to make sure that if I ordered two of them they would come from the same lot. Funny, I thought then that I wouldnt ever need to order more of it, because of the low charge weights. Then I found that its great in all 38 loads, specifically WC loads, almost any 45acp lead bullet load or jacketed/plated target load. Basically any handgun load you arent wanting max effort from loads great with it.

It just has the tendancy to have a lot of variation from lot to lot.

 

[Walkalong]

AA #2 doesn't seem to be quite as bad as AA#5, but it does vary. I bought a 5 pounder last time, for the reason you stated.