burn rate charts

[FEENIX]

No Feenix, But I just researched what you had posted, If I had some testing on paper fir 168 bergers with 7977, or even re 33 to compare with the h 1000 might have me to make a 4 hour drive this morning, since all I can find now is re33 and 7977 witch is a long drive for maybe no gain or even not replacing my beloved 1000 I can get retumbo 2 hours away but have never used it I hate to break something just to try to repair it? Thank you Feenix this will more than likely put me on a waiting list for some time

BUMMER! That's a long trip. All 3 of my LGS carries the IMR 7977 on the shelves almost regularly but H1000s are scarce or non-existent.

 

[MudRunner2005]

What caliber are you loading for?

Some calibers it is not as close as H1000, but others it is. So, not sure what's going on there... With the STW it shows really similar with 180 grain bullets, but with 300 WinMag it shows that 7977 is noticeably faster, and you would need to drop 2-3 grains lower than you would with your H1000 load. But you compare the .300 Weatherby with them, it is back to being within 1/2-grain... Maybe both powders are more stable in the big magnums, than they are in the .300WM and smaller cartridges?

This place can help you get an idea of where to start with 7977 and compare it to H1000, and you'll see what I'm talking about how it varies with different cartridges.

Take Aim at Rifle Reloading Data | Hodgdon Reloading

 

[red dawg]

I left home at 915 this morning, just got home at 520, 1st thing I done was to get on this site , but I have good news, I went to a hole in the wall gunshop that carries enough reloading stuff that you could carry it out in a grocery bag without the worry of tearing the bag, But he had 4lbs of h 1000 I got 2 of them the next slowest burn he had was imr 4350! But ur question Mud is I use h1000 in 7mmrm 168 bergers and 2506 with 115grn bergers. If anyone needs or wants some mag pro un opened send me a private message, if you live an hour and a half of Springfield Mo

 

[MagnumManiac]

What caliber are you loading for?

Some calibers it is not as close as H1000, but others it is. So, not sure what's going on there... With the STW it shows really similar with 180 grain bullets, but with 300 WinMag it shows that 7977 is noticeably faster, and you would need to drop 2-3 grains lower than you would with your H1000 load. But you compare the .300 Weatherby with them, it is back to being within 1/2-grain... Maybe both powders are more stable in the big magnums, than they are in the .300WM and smaller cartridges?

This place can help you get an idea of where to start with 7977 and compare it to H1000, and you'll see what I'm talking about how it varies with different cartridges.

Take Aim at Rifle Reloading Data | Hodgdon Reloading

The reason you see differing charge weights in comparison between powders in different cartridges is because burn rate is not constant. It changes as expansion ratio and case shape changes. A perfect example is how straight wall cartridges and those with little shoulder make fast powders burn like slower powders, some powders even swap position in certain case sizes. A perfect example is the 338WM and RE19 and RE22. RE19 behaves slower than RE22 in this case, producing higher velocity at the same pressure.
This is why burn charts are not reliable, just because a certain powder behaves a certain way when tested in a calorimeter bomb, does NOT mean it will behave the same in EVERY cartridge design it is used in.

Cheers.
lightbulb

 

[MudRunner2005]

The reason you see differing charge weights in comparison between powders in different cartridges is because burn rate is not constant. It changes as expansion ratio and case shape changes. A perfect example is how straight wall cartridges and those with little shoulder make fast powders burn like slower powders, some powders even swap position in certain case sizes. A perfect example is the 338WM and RE19 and RE22. RE19 behaves slower than RE22 in this case, producing higher velocity at the same pressure.
This is why burn charts are not reliable, just because a certain powder behaves a certain way when tested in a calorimeter bomb, does NOT mean it will behave the same in EVERY cartridge design it is used in.

Cheers.
lightbulb

Sort of like how H110 is more efficient in a .300BLK than a .357 Mag or .44 Mag?

Learn something new everyday. I knew powders would react differently by case size and shape, but had no idea burn rate was not a static factor.