Lot numbers on powder

[shotgunone]

Anyone ever notice much difference in there reloads with the same powder but different lot numbers? I was wondering if there is enough difference in velocities to worry about not making power factor or going over especially in major loadings.

[AzShooter]

Yes. Different lot number can be slower or faster. Best way to check is with a chronograph.

[atbarr]

When you order, ask for each can/jug to be the same lot number.

[Bamboo]

Some powders are known to vary quite a bit from lot to lot (SR4756, Solo1000, etc.) and some are pretty consistent (the VV powders, ball powders like 231, Bullseye, etc.)

I usually try to get as much of the same lot as possible and places like Powder Valley are usually really good about giving canisters from the same lot when requested.

When changing lots it is best to load a sample and chrono check to make sure before loading up a boatload of ammo ASSUMING the velocities/pressures will be the same. Having 1k of loaded rounds that makes 163PF kind of sucks.

Edited October 25, 2015 by Bamboo

[RDA]

When you order, ask for each can/jug to be the same lot number.

That's nice when you buy a lot at the same time from the same vendor, but doesn't work so well when buying months/years apart.

[shotgunone]

Has anybody got some data on how much difference you found in between lots? I guess I'm wondering how significant it is.

Edited October 25, 2015 by shotgunone

[robb315]

Worked a production load up with a 1# can of 7625 before 2014 Ohio State match with a 135gr bayou bullet. Chrono'd at 130 pf. Opened up the 8# can that was a different lot # and proceeded to load 600. Chrono'd that load just to be sure and it came in at 125.4 pf. Had to bump up powder drop .3 gr

I will always chrono between lot #'s now no matter what powder it is.

Edited October 25, 2015 by robb315

[RPatton]

When loading for a big match where they were going to Chrono I always loaded a few and tested them even if it was the same load I had always used. I had to adjust the charge more than once to keep the PF where it should be. Can't say for sure it was a powder lot or the barrel but chronoing before loading a large batch seems to work out.

[robb315]

When loading for a big match where they were going to Chrono I always loaded a few and tested them even if it was the same load I had always used. I had to adjust the charge more than once to keep the PF where it should be. Can't say for sure it was a powder lot or the barrel but chronoing before loading a large batch seems to work out.

I was the same way. I didn't expect that much swing between lot #'s though.

[DougCarden]

If you order in a bunch of powder and have a pound or two left of your old batch you can mix them together. Then work your load up. Usually you will be within 0.01grain or two of the original load and you won't have to guess.....

DougC

[kevin c]

I never worry about my ammo making PF.

I shoot production 9mm with VV N320 at ~ 135 PF (my Glocks seem to run more reliably at that PF range), and haven't been close to the PF floor in years.

If you ride the ragged edge though, even with a very consistent powder like N320, consistent bullets and uniform brass, you can still get caught by the almost inevitable variations from one chrono box to the next (the infamous Chrono Voodoo). So, yeah, chrono the new powder lots (I still do, though it's more an academic exercise because the numbers are pretty uniform from lot to lot), but don't expect that that new lot loaded to 127 PF or 167 PF is always going to fly.