Changing lot numbers on powder

[FowlMouthA400]

Fixing to work up a load for 7 prc and I had just enough leftover powder (H4831SC) to get some test loads made. Will have to go to a fresh LB after the initial load test. Will it be a big enough change that the test will be a waste. I’m fairly new to loading. And never encountered this before.

 

[gentleman4561]

I would say no, a bench rest shooter would probably say yes.

I would not worry unless you are very close to max, but I would also listen to Hornady podcast linked below before you spend any more time testing loads.

The truth is that stuff like OCW, Ladder, Satterlee etc. are generally a complete waste of time.

More powder=more velocity. If you load consistent ammo and shoot it through a quality firearm then it should shoot well.

https://vimeo.com/930368810

 

[wapitibob]

I mix lots and don't worry about it.

 

[Vern400]

Next time, put the leftovers in the new can and mix it up. Like making sure 2 cans of paint match. Probably nothing to worry about.

 

[sndmn11]

Fifth vote for it not mattering.

 

[Schmo]

It only matters if it’s Alliant powder!

 

[BBob]

Will it be a big enough change that the test will be a waste.

It depends. Some powders lot to lot velocity variance have been traditionally good and some have not. One lot of powder might be fine pressure wise and a change can put you over and too hot. I’ve seen Varget vary 50+fps from one lot to another. Will you be able to get a velocity for your 1st lot and be able to follow up with the 2nd lot?

 

[FowlMouthA400]

It depends. Some powders lot to lot velocity variance have been traditionally good and some have not. One lot of powder might be fine pressure wise and a change can put you over and too hot. I’ve seen Varget vary 50+fps from one lot to another. Will you be able to get a velocity for your 1st lot and be able to follow up with the 2nd lot?

Yes I should

 

[gpkhill2]

I’ve been loading for 30 plus years. From what I’ve seen 99% of the time it doesn’t matter.

 

[Article 4]

for 99% of shooters, doesn't matter. Do it

 

[TaperPin]

It doesn’t matter, until it does. The biggest difference I’ve personally seen was 50 fps, which is significant. I don’t worry about it and simply do a quick check on a few rounds. Crap lots, either velocity or accuracy, simply get used for plinking/training rounds and I’ll never mix.

Every year someone has a weird lot and everyone convinces them to mix it with another good lot and all it does is create two bad lots, that is still significantly different from a normal one. The worst was a guy who had terrible accuracy with a new 8lb jug, so he was convinced to buy a second 8 lb jug and mix them - the rifle shot like crap with the mixed lot. I suggested buying a single pound, don’t mix it, and if accuracy came back the problem was the first powder. The problem was that first bag jug, but he now has $800 of crap powder sitting on a shelf.

 

[A.baird7]

I switched lots in my 6.5 prc of h4831sc and started having a lot of pressure signs including cracking a case near the case head. Chrono says I gained 60 fps. Sometimes lot to lots are different, sometimes it’s not