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
solid copper bullet performance
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="Beng" data-source="post: 858699" data-attributes="member: 37512"><p>To elaborate on jfseaman's post, the necessary twist rate for sufficient stabilization of a bullet is a function of bullet length. The longer the bullet, the shorter the twist rate, required to stabilize the bullet.</p><p>Since copper and brass are less dense (lb/in³) than lead, the same mass of copper requires more volume than lead. Thus monolithic copper bullets have to be longer than their respectively heavy lead core counterparts. Longer bullets require a shorter twist rate to stabilize properly. Thus a 130gr monolithic copper bullet might need a shorter twist than a 130gr lead core bullet, ss long as Bullet design is similar. Meaning, we aren't comparing flat base, round nose copper bullets to 15cal secant ogive, boat tail lead core bullets.</p><p>A 100gr .243cal monolithic copper bullet has the same sectional density as a 100gr .243cal lead core bullet.</p><p></p><p><u><strong>sd=m(gr)/7000*cal(in)²</strong></u></p><p></p><p>Ballistic coefficient is not a function of bullet lenght, but of ogive and boattail design. An aerodynamically very efficent design is, due to its long ogive and boattail, usually a long bullet, but not all long bullets are of this design and thus not all long bullets are aerodynamically efficient (have a high bc).</p><p>Since monolithic copper bullets are naturally longer than lead core bullets, you can create round nose copper bullets nearly as long as lead core VLD type bullets of the same mass and caliber. The former, of course, have a much higher form factor and thus lower bc.</p><p>ps: even better example:</p><p>The .284"cal 175gr TSX is .06" longer than the .284"cal 175gr SMK, the formers formfactor (i7) is .577 lb/in² higher(worse).</p><p></p><p><strong><u>bc=sd/i</u></strong></p><p></p><p>Just making sure those new to ballistics understand too.</p><p>If you are interested in ballistics stevotary, then I can highly recommend Bryan Litz' "Applied Ballistics for Long Range Shooting". It will explain everything you need for longrange hunting and gives good suggestions for further study.</p></blockquote><p></p>
[QUOTE="Beng, post: 858699, member: 37512"] To elaborate on jfseaman's post, the necessary twist rate for sufficient stabilization of a bullet is a function of bullet length. The longer the bullet, the shorter the twist rate, required to stabilize the bullet. Since copper and brass are less dense (lb/in³) than lead, the same mass of copper requires more volume than lead. Thus monolithic copper bullets have to be longer than their respectively heavy lead core counterparts. Longer bullets require a shorter twist rate to stabilize properly. Thus a 130gr monolithic copper bullet might need a shorter twist than a 130gr lead core bullet, ss long as Bullet design is similar. Meaning, we aren't comparing flat base, round nose copper bullets to 15cal secant ogive, boat tail lead core bullets. A 100gr .243cal monolithic copper bullet has the same sectional density as a 100gr .243cal lead core bullet. [U][B]sd=m(gr)/7000*cal(in)²[/B][/U] Ballistic coefficient is not a function of bullet lenght, but of ogive and boattail design. An aerodynamically very efficent design is, due to its long ogive and boattail, usually a long bullet, but not all long bullets are of this design and thus not all long bullets are aerodynamically efficient (have a high bc). Since monolithic copper bullets are naturally longer than lead core bullets, you can create round nose copper bullets nearly as long as lead core VLD type bullets of the same mass and caliber. The former, of course, have a much higher form factor and thus lower bc. ps: even better example: The .284"cal 175gr TSX is .06" longer than the .284"cal 175gr SMK, the formers formfactor (i7) is .577 lb/in² higher(worse). [B][U]bc=sd/i[/U][/B] Just making sure those new to ballistics understand too. If you are interested in ballistics stevotary, then I can highly recommend Bryan Litz' "Applied Ballistics for Long Range Shooting". It will explain everything you need for longrange hunting and gives good suggestions for further study. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
solid copper bullet performance
Top