Powder and pressure question

[Shootist43]

The pressure as seen with Hodgdon loads that I got off of Loaddata.com:

H1000 at 51,900 cup vs 52,800 for H4350

The velocity is H1000 2940fps & H4350 2999 fps

Grains 76 vs 69

Also, the H1000 is a compressed load and H4350 is not. I thought that interesting because I understand from the Lee Manual that you typically get better accuracy with a fuller case.

Powder weight and powder volume are not one and the same. The case may be almost full using the 4350 even though it is only 69 Grs. Someone with access to Quick Load could tell you what percentage of the case was filled but you would have to give them a bullet (for calculation purposes) and a seating depth (the overall length of a loaded cartridge). They will also need to know how many grains of water your empty case will hold. You are correct in that the case should be filled to 90% or greater.

 

[Bob Nelson 35Whelen]

I am looking at options to develop loads for a 308 Norma Mag that is currently being built (something to do while waiting for lunch). I noted that for 180 gr Hodgdon H1000 and H4350 produce similar velocity (+- 50 fps) but the H1000 operates at a lower pressure. The difference seems slight with H1000 at 51,900 cup vs 52,800 for H4350, but I really don't know the significance of this variance. My question is when developing a load is there any reason to consider using one powder over the other based on pressure, assuming it is within a safe operating range?

@Pheroze.
H4350/ADI 2209 is faster burning than H1000/adi2217 and requires less powder to reach similar pressures and velocities.
In the 30/06 ADI 2209/H4350 gives the same pressure and velocities with 150 grain projectiles as ADI 2206H/ H4895 but you use less powder with the faster powder.
My aim is to load to the best accuracy with the highest velocity and this may involve different burn rate powders.
Bob

 

[Bob Nelson 35Whelen]

I'm a reluctant hamdloader. When absolutely necessary only.

That being said, 4350 is awesome because it works really well in almost everything worth owning from a 500 nitro for black, a 375hh, a 318 Westley and your .308. One powder to rule them all!

@rookhawk
Depending on the projectile weight H4350 could severely limit the velocity of the 308 as it is considered a slow powder in the 08. In the 375 it would be considered medium and ideal
Bob

 

[bruce moulds]

yes bob, verget/ar2208 is more appropriate for 308.
bruce.

 

[Wyatt Smith]

308 Norma Magnum Bob.

 

[gbflyer]

Load for 30-338 Win which is by all practical purposes the same cartridge. I have found IMR4350 and 212-220gr projectiles a good match. I’ve found H1000 to be a little slow.

 

[Bob Nelson 35Whelen]

308 Norma Magnum Bob.

!@Wyatt Smith
If'n you want load data,for the 308 Norma mag flick me a PM mate.
Bob

 

[Wyatt Smith]

I’m sorry Bob, the OP is loading the 308 Norma. I thought you may have accidentally thought he was loading the 308 Winchester.

 

[Bob Nelson 35Whelen]

I’m sorry Bob, the OP is loading the 308 Norma. I thought you may have accidentally thought he was loading the 308 Winchester.

@Wyatt Smith
Yes I did thanks mate