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
The science to twist rates
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="groper" data-source="post: 454418" data-attributes="member: 12550"><p>This is a simplified way of looking at the mechanics of it, which is perfectly fine for most purposes.</p><p></p><p>As you make a bullet longer in the same caliber, your increasing its tranverse inertia moment (nose to tail) alot, and only increasing the axial inertia moment a little, so it get more unstable the longer you make it. This is assuming a constant density construction that is.... Once you start altering the density by using plastic tips or hollow core meplats etc, then you can get away with making them longer WITHOUT increasing the transverse inertia moment. See my point? This has been one of the design improvements of modern bullets, using hollow and plastic tips etc... it allows designers to make the bullet a bit longer and more aerodynamically streamlined for less drag whilst still maintaining stability from common twist rate barrels.</p></blockquote><p></p>
[QUOTE="groper, post: 454418, member: 12550"] This is a simplified way of looking at the mechanics of it, which is perfectly fine for most purposes. As you make a bullet longer in the same caliber, your increasing its tranverse inertia moment (nose to tail) alot, and only increasing the axial inertia moment a little, so it get more unstable the longer you make it. This is assuming a constant density construction that is.... Once you start altering the density by using plastic tips or hollow core meplats etc, then you can get away with making them longer WITHOUT increasing the transverse inertia moment. See my point? This has been one of the design improvements of modern bullets, using hollow and plastic tips etc... it allows designers to make the bullet a bit longer and more aerodynamically streamlined for less drag whilst still maintaining stability from common twist rate barrels. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
The science to twist rates
Top