Second guessing - Hogdon starting load higher than my manual's max load

[thebaron]

I'm loading up a new load for 223 with 50 grain Varmint Grenades & H4895

I fired up Hodgons reloadinf guide and started at min load (25gn)and increased by 0.5 grains to max (27.5).

Once done I checked for fun in my manual at home and saw the max load is 24.8!!

What do?

 

[legi0n]

use your manual to work up a load and if there are no signs of pressure and if the velocities are below the book, go by hodgdon's

 

[legi0n]

Lee's manual shows the same as Hodgdon's
Hornady 9th has no load for H4895

 

[thebaron]

Lee's manual shows the same as Hodgdon's
Hornady 9th has no load for H4895

Thanks. A second book confirming the data makes me feel a bit better.
The low data comes from Barnes. My Nosler and Speer books have no H4895 data.
I will start at the Barnes data and work up to the Hodgon if pressures and velocities cooperate.

 

[legi0n]

I looked the varmint grenades up and they are lead free. This might mean solid copper and then the lower charges are justified.
You see, the solid copper bullets are harder then jacketed lead and take more effort to engrave in the rifling. This causes the pressure to spike higher hence the lower loads.

 

[kodiakjack]

I looked the varmint grenades up and they are lead free. This might mean solid copper and then the lower charges are justified.
You see, the solid copper bullets are harder then jacketed lead and take more effort to engrave in the rifling. This causes the pressure to spike higher hence the lower loads.

Not solid copper. Copper tin alloy something or other that's softer than lead.

 

[legi0n]

then it must be the length of the bullet that reduces the case capacity

 

[thebaron]

then it must be the length of the bullet that reduces the case capacity

It is a very long bullet. Even though it's 50 grain Barnes reccomends a minimum 1-10 twist for it.

 

[hometownhero]

You wouldn't have pressure issues with a full case of 4895 or varget for that matter. Even for a 60gr bullet you are still looking at 26-27gr max loads. Back when I had a 223 I was shooting 60gr berger varmint fb with 27.5gr of varget at 3100 and change fps.

 

[trevj]

Not solid copper. Copper tin alloy something or other that's softer than lead.

Yep. Powdered metal pressed together. Lighter than a lead bullet of the same dimensions, thus longer, and requiring a faster twist than you would normally expect for the weight. The formula for determining rifling rate of twist to stabilize a bullet (Greenhill Formula?) is based off bullet length, not weight.http://kwk.us/twist.html

Cheers
Trev