Powder burn rate

[Steve Blair]

Ok, the case capacity for my resized Wolf Gold 223 Rem to 25-223 is 30.6gr of water

[br]
Your cartridge is really close to the .257 Ugalde, which QL lists at 31.0 grains H2O. [br]
What bullet do you want to use and what is the OAL?

 

[Brians356]

Ok, the case capacity for my resized Wolf Gold 223 Rem to 25-223 is 30.6gr of water

[br]
Your cartridge is really close to the .257 Ugalde, which QL lists at 31.0 grains H2O. [br]
What bullet do you want to use and what is the OAL?

Forgive me for taking the liberty to paste from a previous post:

"87gr Speer TNT's, they are .920" long ... ... OAL is 2.260". "

I find .257 Ugalde in Ken Howell's book, and that one is an improved 223 Rem case (minimum body taper, 40-deg shoulder) and since Howell says just "fireform 223 Rem brass w/ inert filler" I conclude the Ugalde case will have several more grains capacity than 223 Rem.

What does QL list as standard 223 Rem case capacity?

FWIW I measured these 223 Rem cases, for reference:

Mfgr. Empty H2O
----------------------
RWS 101.5 30.6
Win 94.7 31.1
Rem 95.0 30.7
L.C. 94.5 31.3

Still, it seems safe enough to use what QL suggests for a starting load and work up, even if the Ugalde case is a little bigger than 31.0 grains.

 

[Steve Blair]

I agree that it must be more. QL lists .223 Rem as 28.8. Ir looks like 24.0 should be a reasonable starting load at ~45ksi. Be careful and watch for pressure signs. It should be a very efficient cartridge.

 

[Brians356]

I agree that it must be more. QL lists .223 Rem as 28.8.

Makes me wonder if QL doesn't use unfired case capacity.

 

[Steve Blair]

I don't think so. The manual is very specific.

 

[Brians356]

I don't think so. The manual is very specific.

I guess I use "heavy water" then.

 

[Steve Blair]

I never use their case capacity numbers unless a WAG is needed.