Do you notice a change with different lots of powder?
I know your supposed to re workup a load with new lots and I always do. But I have noticed when reworking a load that I always end up with the same powder charge. How much of a variance have you guys noticed? Thanks
Aren't canister powders, by definition, supposed to be uniform?
Originally Posted By Him:
Aren't canister powders, by definition, supposed to be uniform?
From what I heard when they make a new lot of powder the ingredients could vary a little bit. I would think its impossible to have the same exactly burn rate from lot to lot. But I really have no idea.
I never have.
I have never had a problem. Most of my loads are .5 to 1 grain below listed max.
With full bore max loads, I would drop back a grain and work back up.
It depends on the powder, Varget has changed several time that I'm aware of, same with others.
'Borg
It can happen, but generally the better powders are not that variable from lot to lot.
My experience is IMR 4320 will vary from lot to lot.
I have seen it on older lots of powder ( 15- 20 years ago ). I think it is good practice to follow the re-work it advise. I suspect that newer production powder has much less lot to lot variance. One other scenario would be , getting a lot that is eventully recalled.
Originally Posted By We-rBorg:
It depends on the powder, Varget has changed several time that I'm aware of, same with others.
'Borg
Sir, my answer to the Op's question is the same as yours, ie: it depends on the powder. When I use IMR 4895 I used to chronograph my initial loads from a new lot of powder. When the chronograph data showed no significant changes in velocities I stopped working up loads with that powder. I found the same true for IMR 4064, VV N540, and VV N140. Load testing I did with Varget showed significant variations in velocity from lot to lot so I always work up charges with that powder when I have a new lot. Most AA stick rifle powders have a similar lot to lot variation. Mostly due to the lot to lot variation I avoid powders that exhibit such characteristics. JMHO, 7zero1.
Some may frown upon this, but I treat my powders like whiskey- ie, I blend them. Same powder only of course.
As I buy more of a given powder, I will mix together old and new lots then put them back into the original containers. In my opinion, this smooths out any lot to lot inconsistancies and I can use the same load data.
Originally Posted By LexDiamonds:
Some may frown upon this, but I treat my powders like whiskey- ie, I blend them. Same powder only of course.
As I buy more of a given powder, I will mix together old and new lots then put them back into the original containers. In my opinion, this smooths out any lot to lot inconsistancies and I can use the same load data.
I am not gonna lie, i have been known to do this from time to time as well. I recently purchased a big 8lb jug of W231, which still has plenty of room empty at the top, and i had 2 small 1lb bottles that I hated storing next to the big jug, so i mixed them all together, shook them up real well, and loaded a few rounds at .2 below what i normall load, and then a few at my normal load, tested, and results were the same and then i feel OK doing mass loads. I am not saying its OK to do with all powders, just in the few times I have done it, it worked for me with the mass blending.
Yes - at least with my favorite pistol powder: Solo 1000
(can also be used in Shotguns)
OTOH, I chrono my loads carefully and I use very small amounts under heavy bullets. Differences in lots are apparent under these circumstances. Others might not notice at all.
Maybe should of said this in the OP but the powder is Reloder 15. I have found it to be incredibly consistent.
Originally Posted By D-RAS03:
Maybe should of said this in the OP but the powder is Reloder 15. I have found it to be incredibly consistent.
As i said in 2 post above yours, i did the same thing with RL15 when I got a big jug, had 1.5lbs of smaller, i poured them in, mixed up, and did a very small batch of 1g lower and and then was good to go with my full power 44.0gr RL15 under a 168g Amax in 308 with Win Brass :). Like i said, most people probably wouldnt do this, but it seemed to work out fine for me, so just use your own caution.
When I was reloading 9mm subsonic for suppressor use with an Uzi, I found that with Bullseye I had to use a different amount with each lot in order to get the same average velocity. However, the powder charges only had to vary by 0.1gr from the lot of powder I initially started with.
Alliant gunpowders bear watching, especially Reloder 19 and 21. Reloder 15 was very uniform through many bottles, then I got one that is way off the tracks.
REX gunpowder has remarkable variation from lot to lot. I think I've loaded with three different bushing sizes to throw the same weight of REX-1 from different lots.
