Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Understanding cartridge efficiency
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="epoletna" data-source="post: 1914797" data-attributes="member: 87371"><p>Stiltsville uses the example I was going to bring up: the .300 H&H versus the .300 WSM. Two extremes in case design, and you can see from ballistics tables how they stack up.</p><p></p><p>This reminds me of a comment I made in this forum in the past two years: three classic cartridges from the last century are remarkably alike in profile: the .50 BMG, the .30-06 and the .223. It is not a perfect duplication from one to the other, as the .223 is a little "stubbier" than the other two, but there is no extremely different case profile. </p><p></p><p>Then as we reach the last half of the last century we begin to see a movement toward shorter and fatter cases, mostly with a sharper shoulder: the 6 PPC and the various Creedmoor variations.</p><p></p><p>Either powders began to burn with different pressure curves, or wildcatters began to notice that shorter cases with greater diameter used the powder better. Does "better" mean more efficiently? I don't know the answer to that, except to note that the "newer" designs seem to use less powder than the older case designs to achieve the same velocities. I suspect the shorter/fatter designs recognized the difference between burning black powder (older, straight-walled or long-taper cases) and burning smokeless powders (shorter/stubbier cases, but with sharp shoulders). All of which raises the question "should we try new designs even shorter and fatter"? Magazines and action ring diameters probably make that impossible, but if you could get around those limitations, would shorter and fatter improve efficiency?</p><p></p><p>Ackley was chasing this equation half a century ago. And we're still chasing it. I like to think we're getting more "efficiency" out of our cartridges and powders, but I cannot make that argument with more than anecdotal evidence.</p></blockquote><p></p>
[QUOTE="epoletna, post: 1914797, member: 87371"] Stiltsville uses the example I was going to bring up: the .300 H&H versus the .300 WSM. Two extremes in case design, and you can see from ballistics tables how they stack up. This reminds me of a comment I made in this forum in the past two years: three classic cartridges from the last century are remarkably alike in profile: the .50 BMG, the .30-06 and the .223. It is not a perfect duplication from one to the other, as the .223 is a little "stubbier" than the other two, but there is no extremely different case profile. Then as we reach the last half of the last century we begin to see a movement toward shorter and fatter cases, mostly with a sharper shoulder: the 6 PPC and the various Creedmoor variations. Either powders began to burn with different pressure curves, or wildcatters began to notice that shorter cases with greater diameter used the powder better. Does "better" mean more efficiently? I don't know the answer to that, except to note that the "newer" designs seem to use less powder than the older case designs to achieve the same velocities. I suspect the shorter/fatter designs recognized the difference between burning black powder (older, straight-walled or long-taper cases) and burning smokeless powders (shorter/stubbier cases, but with sharp shoulders). All of which raises the question "should we try new designs even shorter and fatter"? Magazines and action ring diameters probably make that impossible, but if you could get around those limitations, would shorter and fatter improve efficiency? Ackley was chasing this equation half a century ago. And we're still chasing it. I like to think we're getting more "efficiency" out of our cartridges and powders, but I cannot make that argument with more than anecdotal evidence. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Understanding cartridge efficiency
Top