Got bored today and started playing with CAD. Took the dimensions of some SAAMI chambers and overlaid them for the hell of it. The comparison chamber is a .223 Rem SAAMI
This is a .223 Rem and .225 Win chamber
This is a .30-30 chamber with a 40 deg shoulder, meeting the .223 at the shoulder/neck intersection. I'm calling this Proposition 1
This is the above on a .303 British chamber. This is Proposition 2
This is the above with a 23 degree shoulder. This is Proposition 3
This is the above on a .30-30 chamber. This is Proposition 4
I calculated the area of each drawing and used it to put together an area ratio compared to .223 Rem, which will allow some semblance of volume ratio without having to make solids of revolution, which I haven't done since I took Calc 1. I will be doing so eventually. In order of least to greatest:
.223 Rem 0.638567 in^2
Prop 4 0.675793 in^2 1.0582962:1 compared to .223 Rem
Prop 1 0.686215 in^2 1.0746171:1
Prop 3 0.708853 in^2 1.1100683:1
Prop 2 0.716505 in^2 1.1220514:1
.225 Win 0.764076 in^2 1.1965479:1
It was a fun exercise. I'm thinking anything based on the .303 Brit would need to be "straightenned" to prevent excessive case stretching, but that's just a hunch based on the flashlight-beam-sized scope of understanding I have of this so far. It's just a good looking cartridge, though, and I don't think it gets enough love here. The Aussies apparently made a bunch of wildcats on them.
I have PO Ackley's books on the way, and am looking forward to reading them. I've been told they are a staple of any wildcatter's diet.