idahoron

Has anyone documented a "hot" can of powder. By hot I mean faster burn rate making the load shoot higher? I was shooting today and had my rifle pretty well dialed in at 50, 100, and was almost gold on 150 when I ran out of powder. I opened a new can and my bullets immediately started hitting 8" higher at 150 yards. I confirmed this at 100 yards it was now hitting higher.
My flask and quick loads have been in a cool dry area since October. They were under my reloading bench in my house next to the computer I am on right now. There are only two things I can think of.

#1- moisture- I know that there has been no water or any other fluids in the area. The moisture in the air would be the same as the rest of the house. This powder was not in a air tight container.

#2- Hot can of powder- The outside temp is in the 50's and all the powder was in shade as I was shooting. This can was sealed and was in a air tight container.

I am a little confused at this to be honest. I have never documented a change like this to this extent. I didn't have another rifle with me that was sighted in to test both powders but the rifle I was using was super close. I had to lower the sights by a lot on the new powder. I was using a Williams FP peep and I had to lower the sights by two marks on the scale. It was right at 42 "clicks" that seems like a lot of rise in elevation to me.
Both powders were Pyrodex P. I don't have the production code on the older powder dang the luck.

cayugad

I never saw a new jug of powder to that extreme of 8 inches. I was shooting Wano Black Powder once and had the rifle sighted in dead on at 50 yards. Ran out of powder, got a new jug of Wano and suddenly I was almost three inches high with the same load.

bronko22000

Well that seems really odd to have that much of a difference. Maybe your older stock was older than you think?! Too bad you don't have the lot code to find out.
Maybe a call to Hodgen would be in order to see if this is a rarity. Maybe provide them with the "hot" can's lot number. I'm sure they have test results if they have any QC at all.

lemoyne

I have experienced as much as 6" with Pyrodex, this was in a flask, I am not sure if it is the metal of the flask or if it starts deteriorating from the O2 in the air once you open it.

BarnesAddict

I use T7 pellets in my Ultimate. When I purchase propellant its purchased by the case. Its kept in a cool DRY and humidity controlled environment.
The differences I've noticed haven't been as severe as many state will happen when shooting pellets. At least not at ranges out to 200 yards. However, I have certainly noticed the difference between the cases of propellant at longer ranges. My first two cases last year shot to the same POI at all distances to 400yds, matching my CDS turret. The third case last summer was shooting much higher, thus throwing off my CDS turret at long range. Still it remained extremely close out to 200, but at 300 it was high and at 400 it was 6" high.
I'm now starting on another new case of propellant and I have Lane's tubes loaded with both lots. I'll have to shoot up last years charges first, then proceed to zero with the new case.
Yup, I have to pay close attention.....

GoexBlackhorn

I'll bet had you purchased the new jug at the same time as the old jug you just used, then kept both jugs stored in the exact same environment, both jugs would have likely shot to near/ or same POI.

Smaller grain synthetic powders (FFF/P) seem more affected by moisture, temp changes......etc. The plastic jug contents are not moisture-proof after opening, then becoming only moisture resistant. Hodgdon Inc will tell you other ways the powder degrades over time.

This is why I go to the range with enough powder to burn that day. This is why I never return extra hunting powder loads to the original jug, upon returning from the woods.