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
Hunting
Elk Hunting
6.5mm copper monos for Elk - LRX vs CX vs E-tip vs CEB vs Hammer vs Lehigh
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="western living" data-source="post: 3004033" data-attributes="member: 128694"><p>I've used the Berger calculator, but it is not using the Miller formula. From what I can tell, Berger is primarily interested in calculating the loss of BC from their calculated Sg.</p><p></p><p>If I put a reasonable muzzle velocity of 3200 fps into the Berger calc at 5000 feet with a temp of 0 deg. F, I get an Sg of 1.28 which indicates I would be losing 7% of the BC. Instead of a BC of .468, I'd be getting .437 -- still better than Barne's 120 grain TTSX at .412</p><p></p><p>I won't know without testing, but I don't believe I'd get bullets keyholing under the above conditions. What I don't know and can't easily test is what I'd see with terminal performance.</p><p></p><p>Using the Miller formula under the same exact parameters - same bullet, same specs, 5000 feet and 0 deg. F, 3200 fps -- I get an Sg of 1.752. If I make conditions worse, 4000 feet, -5 deg. F, I still get a Miller-formula Sg of 1.666</p><p></p><p></p><table style='width: 100%'><tr><td>Stability</td><td></td><td></td><td></td></tr><tr><td>Input Data</td><td></td><td></td><td></td></tr><tr><td>Caliber:</td><td>0.264 in</td><td>Bullet Weight:</td><td>127.0 gr</td></tr><tr><td>Bullet Length:</td><td>1.402 in</td><td>Plastic Tip Length:</td><td>0.199 in</td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Muzzle Velocity:</td><td>3200.0 ft/s</td><td>Barrel Twist:</td><td>9.0 in</td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Temperature:</td><td>-5.0 °F</td><td>Pressure:</td><td>25.37 in Hg</td></tr><tr><td>Output Data</td><td></td><td></td><td></td></tr><tr><td>Stability:</td><td>1.666</td><td></td><td></td></tr></table><p></p><p>I'm not just wanting to argue calculator results. I can see the Sg results for myself. The question is: how will Sg affect terminal performance?</p><p></p><p>According to Hammer, they're essentially saying that I need an Sg of 1.9 to get good terminal performance with their bullets -- they say a Miller-formula Sg of 1.5 at sea-level, which would result in a Miller-formula Sg of 1.9 where I live (and even higher where I hunt).</p><p></p><p>If that's the case with Hammer bullets, what kind of Sg would I need to expect good performance from expanding bullets like TTSX, LRX, CX?</p></blockquote><p></p>
[QUOTE="western living, post: 3004033, member: 128694"] I've used the Berger calculator, but it is not using the Miller formula. From what I can tell, Berger is primarily interested in calculating the loss of BC from their calculated Sg. If I put a reasonable muzzle velocity of 3200 fps into the Berger calc at 5000 feet with a temp of 0 deg. F, I get an Sg of 1.28 which indicates I would be losing 7% of the BC. Instead of a BC of .468, I'd be getting .437 -- still better than Barne's 120 grain TTSX at .412 I won't know without testing, but I don't believe I'd get bullets keyholing under the above conditions. What I don't know and can't easily test is what I'd see with terminal performance. Using the Miller formula under the same exact parameters - same bullet, same specs, 5000 feet and 0 deg. F, 3200 fps -- I get an Sg of 1.752. If I make conditions worse, 4000 feet, -5 deg. F, I still get a Miller-formula Sg of 1.666 [TABLE] [TR] [TD]Stability[/TD] [TD][/TD] [TD][/TD] [TD][/TD] [/TR] [TR] [TD]Input Data[/TD] [TD][/TD] [TD][/TD] [TD][/TD] [/TR] [TR] [TD]Caliber:[/TD] [TD]0.264 in[/TD] [TD]Bullet Weight:[/TD] [TD]127.0 gr[/TD] [/TR] [TR] [TD]Bullet Length:[/TD] [TD]1.402 in[/TD] [TD]Plastic Tip Length:[/TD] [TD]0.199 in[/TD] [/TR] [TR] [TD][/TD] [TD][/TD] [TD][/TD] [TD][/TD] [/TR] [TR] [TD]Muzzle Velocity:[/TD] [TD]3200.0 ft/s[/TD] [TD]Barrel Twist:[/TD] [TD]9.0 in[/TD] [/TR] [TR] [TD][/TD] [TD][/TD] [TD][/TD] [TD][/TD] [/TR] [TR] [TD]Temperature:[/TD] [TD]-5.0 °F[/TD] [TD]Pressure:[/TD] [TD]25.37 in Hg[/TD] [/TR] [TR] [TD]Output Data[/TD] [TD][/TD] [TD][/TD] [TD][/TD] [/TR] [TR] [TD]Stability:[/TD] [TD]1.666[/TD] [TD][/TD] [TD][/TD] [/TR] [/TABLE] I'm not just wanting to argue calculator results. I can see the Sg results for myself. The question is: how will Sg affect terminal performance? According to Hammer, they're essentially saying that I need an Sg of 1.9 to get good terminal performance with their bullets -- they say a Miller-formula Sg of 1.5 at sea-level, which would result in a Miller-formula Sg of 1.9 where I live (and even higher where I hunt). If that's the case with Hammer bullets, what kind of Sg would I need to expect good performance from expanding bullets like TTSX, LRX, CX? [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Hunting
Elk Hunting
6.5mm copper monos for Elk - LRX vs CX vs E-tip vs CEB vs Hammer vs Lehigh
Top