Imr4350 imr7828 h1000 powders

[baydog]

I got a powder question...For some I'm sure understanding powders is very simple but for me it's one of the hardest things to understand the burn time and why some guns like a faster powder and some like slower..it's a trial and error thing for me...So out of these three powders IMR4350-IMR7828-H1000 and loading for a 257wby as long as I stay within the max safe load zone which powder would produce the fastest FPS using the same bullet?...and does a short cut powder make any diffrence than a regular cut powder
Thanks

 

[Hondo64d]

7828 or H1000 is going to give the highest velocity of the three you mention in the .257 Wby. Has to do with expansion ratio or how much powder you are trying to force down a given bore size. Generally, the greater the powder charge (case capacity) to bore size ratio, the slower powders are going to provide more velocity. Bullet weight also has an effect. The heavier the bullet in a given cartridge, the slower the powder for higher velocities. The differnces in burn rate are not nearly as pronounced for different bullet weights in the same cartridge when compared to case capacity/bore size.

John

 

[okie man]

I burn more 7828 than anything in my 257 weatherby

 

[baydog]

So the bigger the bore size the slower powders seem to produce more FPS? And as far as case capacity I've found that the it seems to work out for me that the fuller the case is with powder while staying within max load limts according to the manuals I use, the more accurate the ammo is...Is that what you seem to find too? What I'm trying to say is that to me without shooting a compressed load and staying within the max guide lines a 94 to 97% case full of powder if that's what the suggested max load weights out to be will be more accurate than a 60 to 65% case full....MOST of the time...
Thanks
Scotty

 

[baydog]

I bought a 1 pound can of the 7828 last week and gonna load some tommrrow. All they had was short cut powder no regular cut. I didn't know what he meant by short cut so I asked and the pellets are cut short so the flow better throught the scales and in the neck of the case is what I was told but when I asked if it would change the burn rate he wasn't sure, it wasn't a good answer but at least it was a honest answer.. Never have used the 7828 before but tomrrow I'm gonna give it a try. I see that in my Nosler book it is faster or more FPS compared to the H1000 and 4350 when shooting the same weight bullet. Do you know if short cut powder makes any diffrence?
Thanks
Scotty

 

[PGJPJ]

7828 and 7828ssc have the same burn rate. Same with H4831 and H4831sc. You can use the data from one to substitute for the other.

 

[okie man]

You can squeeze a little more short cut in some cases where regular 7828 won't fit! 243 for example. In the 257 I prefer regular 7828 just because it fills the case a little more.

 

[MudRunner2005]

So the bigger the bore size the slower powders seem to produce more FPS? And as far as case capacity I've found that the it seems to work out for me that the fuller the case is with powder while staying within max load limts according to the manuals I use, the more accurate the ammo is...Is that what you seem to find too? What I'm trying to say is that to me without shooting a compressed load and staying within the max guide lines a 94 to 97% case full of powder if that's what the suggested max load weights out to be will be more accurate than a 60 to 65% case full....MOST of the time...
Thanks
Scotty

Not necessarily... Bore size, case size, bore-to-case capacity ratio, burn rate, bullet weight, overbore ratio, fill ratio, etc... Lots of things come into play when determining a proper powder for your cartridge. Just about any cartridge labeled as "magnum" I would start around Reloder 22/Norma MRP and slower powders (my personal opinion).

For the .257 Wby, try Norma MRP, Reloder 25, IMR 7828 SSC, IMR 7977, or H1000. With a Berger 115 VLD or something of similar weight or heavier, I recommend the slower burning powders to get the most fill ratio like IMR 7828 SSC, 7977, and H1000.

 

[MudRunner2005]

I bought a 1 pound can of the 7828 last week and gonna load some tommrrow. All they had was short cut powder no regular cut. I didn't know what he meant by short cut so I asked and the pellets are cut short so the flow better throught the scales and in the neck of the case is what I was told but when I asked if it would change the burn rate he wasn't sure, it wasn't a good answer but at least it was a honest answer.. Never have used the 7828 before but tomrrow I'm gonna give it a try. I see that in my Nosler book it is faster or more FPS compared to the H1000 and 4350 when shooting the same weight bullet. Do you know if short cut powder makes any diffrence?
Thanks
Scotty

IMR 7828 and IMR 7828 SSC have the same exact burn rate. The reason there is a short cut powder, is for cartridges that you are using a compressed load, to get more in it, without having to sacrifice room for seating depth of the bullet in the case. Nothing more, nothing less. For all intents and purposes, they are the same. Even according to IMR, the load data is interchangeable for them.

 

[Hondo64d]

So the bigger the bore size the slower powders seem to produce more FPS? And as far as case capacity I've found that the it seems to work out for me that the fuller the case is with powder while staying within max load limts according to the manuals I use, the more accurate the ammo is...Is that what you seem to find too? What I'm trying to say is that to me without shooting a compressed load and staying within the max guide lines a 94 to 97% case full of powder if that's what the suggested max load weights out to be will be more accurate than a 60 to 65% case full....MOST of the time...
Thanks
Scotty

Not the bigger the bore size the slower the powder, the greater the case capacity to bore ratio, the slower the powder to produce top velocities. Bullet weight also plays a part.

I also tend to load to a close to full case. General consensus is that's where the best accuracy is. But, I have never tested that theory to see if it is true. I don't like heavily compressed loads because they have resulted in inconsistent seating depths for me.

John

 

[Dosh]

Bay, usually with the smaller calibers, the faster the powder. Burn rate slows until you get to the cannons like the big bores and the rate goes back to a faster powder. I loaded for a friend's 460Wby which used Varget, a fast powder. Now you read of some using Retumbo (quite slow) in calibers like 25-06 which I tried and got bughole groups. Go figure. There are burn rate charts "Google" you can print and most load manuals will give case fill percentages. We have huge temp swings here in Az, so the temp stable powders are necessary, like H1000 and some have tried IMR Enduron 7977.

 

[WildRose]

Not necessarily... Bore size, case size, bore-to-case capacity ratio, burn rate, bullet weight, overbore ratio, fill ratio, etc... Lots of things come into play when determining a proper powder for your cartridge. Just about any cartridge labeled as "magnum" I would start around Reloder 22/Norma MRP and slower powders (my personal opinion).

For the .257 Wby, try Norma MRP, Reloder 25, IMR 7828 SSC, IMR 7977, or H1000. With a Berger 115 VLD or something of similar weight or heavier, I recommend the slower burning powders to get the most fill ratio like IMR 7828 SSC, 7977, and H1000.

I'm going to play off your ball a bit here Mud and say that the heavier your bullets get even for the same cartridge the slower the powder you want to use to push it. The slower powders just don't seem to work as well for mid or light for caliber bullets as they do the heavies.

 

[WildRose]

Bay, usually with the smaller calibers, the faster the powder. Burn rate slows until you get to the cannons like the big bores and the rate goes back to a faster powder. I loaded for a friend's 460Wby which used Varget, a fast powder. Now you read of some using Retumbo (quite slow) in calibers like 25-06 which I tried and got bughole groups. Go figure. There are burn rate charts "Google" you can print and most load manuals will give case fill percentages. We have huge temp swings here in Az, so the temp stable powders are necessary, like H1000 and some have tried IMR Enduron 7977.

For consistency and temp stability for large cases it's really, really hard to beat H1000. I've started playing around with RL23 and RL26 in large case magnums and they are showing real promise as well.

 

[MudRunner2005]

I'm going to play off your ball a bit here Mud and say that the heavier your bullets get even for the same cartridge the slower the powder you want to use to push it. The slower powders just don't seem to work as well for mid or light for caliber bullets as they do the heavies.

Yessir, I agree.