Mixing Old and new Powder

[horsemen61]

never mix powder

 

[tightgroup tiger]

Horseman,
Are you telling me that every time you run out of a specific powder and buy more of that specific powder that you start your load development all over again?

 

[Comrade Mike]

never mix powder

Never mix powders that aren't the same thing.

You can safely mix the remainder of a titegroup canister with a new canister of titegroup. Or the remainder of a bottle of Win231 with a new bottle of HP38. Statistically this actually minimizes lot to lot variation.

 

[wlkjr]

I use 4.1 grains of Tite Group. I'm sure glad I don't use more for the rounds that go in the 938. Its pretty snappy stuff.

Not sure what gr. bullet you're using, but I'd drop it down a bit to make it shoot better. 3.6 with a 124 gr.XT and 3.3 gr. with a 147 Berry or XT works really well for me in all three Glocks we shoot. You must be using a 115 gr.

 

[ArchAngelCD]

never mix powder

Never mix powders that aren't the same thing.

You can safely mix the remainder of a titegroup canister with a new canister of titegroup. Or the remainder of a bottle of Win231 with a new bottle of HP38. Statistically this actually minimizes lot to lot variation.

Exactly! Of course you never mix different powders but the same powder is a completely different story.

 

[Walkalong]

Agreed. Only mix the same powder, and only if they throw very close to the same weight for same setting.

I mixed a little leftover AA #5 and HS-6 together once. Both were about the same speed, and about the same density, so I figured what the heck.

I used AA #5 data since it is a bit faster. I loaded some 9MM and .45 and used a "starting" charge". The velocities I got were eye opening , as in way faster than I expected.

OK, experiment over, it's fertilizer now.

 

[buck460XVR]

never mix powder

I have been told by Hodgdon, the distributor of the powders, that H110/W296 are the exact same powder and HP-38/W231 are the exact same powder. When you go to their website and see their load recipes, you see they list the exact same powder charges for those sister powders producing the exact same velocities and pressures. As a handloader I know that even with the same lot of powder, one cannot load it at a different time and shoot it and get the exact same results. Since Hodgdon came up with the same results form both, I assume Hodgdon did not test both, but only one. This tells me again, with confidence, that I am not mixing different powders, but the same powder with a different label. Mixing different lots of powder is like mixing different lots of paint. It doesn't take you farther from the original, but closer than if you had not mixed them.

 

[Slamfire]

In my opinion it is very low risk mixing same powder, different lots, as long as the stuff is not too old.

Powder Brands do shift vendors, I have purchased Accurate Arms powders. lets say AA2495 and AA2520, one jug made in China (and the stuff shot well) and another in Czechoslovakia, and another jug with no name of origin. I have no doubt there is no requirement on any of these makers that their powder mixes without issue with every other manufacturer, so, in my opinion, given that gunpowder is a very complicated mix of ingredients, there is always the risk of incompatibility with powders made by different manufacturers. What could happen, heck if I know , but anyone who has installed any mechanical part found interferences between brands, so maybe there is the chance of weird interactions between the constituents used by different manufacturers.

Gunpowder ages and it does not go benign as it ages. It gets worse. If you mix old gunpowder, decades old, with new gunpowder, and that old gunpowder is at the end of its shelf life, the whole batch is dangerous.

 

[Comrade Mike]

Well like any other load practice there is no absolute. Everything must be taken with a dash of common sense on the side.

 

[sexybeast]

"Dash of common sense"
yeah, but common sense is lacking with some people. I've mixed different batches of the same powder like I wrote, I did notice a "very small" difference but I had no worries or concerns about my loads having a drastic change.

 

[buck460XVR]

Well like any other load practice there is no absolute. Everything must be taken with a dash of common sense on the side.

Exactly...this is why you wouldn't take old powder you knew was dangerous and try to mix it with new powder. This is why you wouldn't mix powder manufactured at different factories decades apart and expect to get safe results. You wouldn't blend powders unless you knew for sure they were both of current production and the formulation had not changed. An example would be IMR4227. The new IMR4227 is not the same formula as the old IMR4227 and uses different data. It is the same formulation as the old H4227 and uses the same data. Still, I wouldn't mix old H4227 with new IMR4227.