How much difference in lots of powder have you guys seen?

[huntoregon]

What kind of differences in velocity and accuracy have you guys seen from lot to lot of the same powder?


I had a load for my 300 win mag with 185 grain Berger classic hunters and 78.5 grains of H-1000 at 3.340" that shot pretty good. Ran out of that pound of powder so I bought some more but it doesn't shoot as fast with the same load and groups opened up.

 

[Barrelnut]

I've seen it with H4350. Supposedly powder makers keep powders lot within 3% as worst case and normally the change is more like 1 ~ 1.5%. An engineer at IMR told me this one day... I know that with my last H4350 lot change, I had to use 5% more powder to get back up to speed.

 

[FearNoWind]

When you change powder lots, better figure on fine tuning he load you used with the last lot. That's why I go i debt to buy enough powder of the same lot to last me two years.

 

[huntoregon]

That's what I am going to start doing. If I find anymore H1000 I will buy all of it that is the same lot.

 

[Dosh]

hunt, Bruno Shooter Supply has H1000 in 1 & 8#.

 

[Bravo 4]

What kind of differences in velocity and accuracy have you guys seen from lot to lot of the same powder?


I had a load for my 300 win mag with 185 grain Berger classic hunters and 78.5 grains of H-1000 at 3.340" that shot pretty good. Ran out of that pound of powder so I bought some more but it doesn't shoot as fast with the same load and groups opened up.

Right at 100 fps with two different lots of H1000. The accuracy didn't change so I just let it be.

 

[Greyfox]

With the Hogdon powders I have not seen differences in accuracy but have seen differences in charge weight to generate comparable velocity from lot to lot. I also make it a practice to buy large quantities of the same lot. Lot variation seems to have gotten better in recent years.

 

[Frank in the Laurels]

Too be honest overall very little with granual/stick powders, it's pretty surprising it's not more than it actually is overall...if you buy it only 8 lb kegs you'll notice it even less, buy the time you use it up you'll have forgotten any difference. Ball powderd , forget it, I banned myself from ever using any of them again for life ..

 

[TBuckus]

.05-1.0 gr difference between some loads. Sometimes a difference between lots, but usually not.

 

[Greyfox]

I experienced the biggest change about 5 or 6 years ago with Retumbo about the time they began labeling for temperature control. Today's Retumbo required 2grs less powder(57gr) to achieve the equivalent velocity of 2975FPS in my 6.5x284. The difference was about 75 FPS. Accuracy and ES omce the velocity was adjusted was the same. More recent lots are pretty good typically within10-15 FPS for different lots.

 

[MagnumManiac]

I worked for ADI, the company here in Australia that produces most of the Hodgdon single base stick powders.
They go to huge efforts to keep the burn rate within 3% of what it should be, humidity and temp are controlled during manufacture, if it fails the 3% swing, it is blended and made into a commercial powder. Canister powder, which is what we buy HAS to comply by LAW to be within that 3%.
I have seen swings of 100fps myself with H1000, Retumbo and H4350.
This is less than 1% swing in burn rate, which is pretty good.
You also have to understand that atmospheric conditions, not just temperature can and does affect velocity and pressure within the gun system.

Cheers.
gun)

 

[Sheldon N]

I've seen lot to lot variations of Varget that required change of as much as 1 g of powder in a 308 to match velocities with the prior node. Had to work through multiple one pounders and ended up spending half my time retuning the load each time I opened a new can. Only 8# jugs for me from now on, if I can help it.

 

[scf]

I had a really bad experience three years ago with RL33 in a 7mm STW. I mistook the product code number for the lot number and went on an elk hunt with a new lot of powder. Needed a follow up shot on an elk and empty was stuck in chamber. Banging on the bolt resulted in the ejector (Remington factory) losing grip and left the empty in the chamber. I had to reduce the load 2.3 grains just to get the bolt to open with the new lot. I learned three things ( don t use 7mm for elk, use stronger ejectors and make absolutely certain of your lot number).