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
7mm PRC Shorter Barrel Twist Rate
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="entoptics" data-source="post: 2770228" data-attributes="member: 104268"><p>Hornady quotes 3000 fps from Precision Hunter 175 ELDX ammo in a 24". Worst case scenario you'll lose 40 fps per inch (probably less, but let's be conservative), and we'll knock another 20 off in case your ammo or barrel comes in slow. So call it 2900 fps</p><p></p><p>At 2900 fps, 50°, standard sea level, a 1:8 twist will give you a 1.91 stability according to Berger's stability calculator (high end of "Comfortable Stability"). The JBM stability calculator, which accounts for plastic tips, gives 3.08 stability.</p><p></p><p>IMO, there's no reason to go to a 1:7.5 twist for that bullet (or any other 0.284 bullet except maybe the heaviest monolithic offerings).</p><p></p><p>Regarding 1000 yard elk performance, that's a tall order, but not out of the question.</p><p></p><p>At 4000' elevation, standard pressure, 50°, 50% humidity and a 2950 fps launch, the ELDX will only be going 1866 fps, and have 1352 ftlbs at impact at 1000 yds. Will that kill an elk? Sure. It doesn't leave much room for error though...</p></blockquote><p></p>
[QUOTE="entoptics, post: 2770228, member: 104268"] Hornady quotes 3000 fps from Precision Hunter 175 ELDX ammo in a 24". Worst case scenario you'll lose 40 fps per inch (probably less, but let's be conservative), and we'll knock another 20 off in case your ammo or barrel comes in slow. So call it 2900 fps At 2900 fps, 50°, standard sea level, a 1:8 twist will give you a 1.91 stability according to Berger's stability calculator (high end of "Comfortable Stability"). The JBM stability calculator, which accounts for plastic tips, gives 3.08 stability. IMO, there's no reason to go to a 1:7.5 twist for that bullet (or any other 0.284 bullet except maybe the heaviest monolithic offerings). Regarding 1000 yard elk performance, that's a tall order, but not out of the question. At 4000' elevation, standard pressure, 50°, 50% humidity and a 2950 fps launch, the ELDX will only be going 1866 fps, and have 1352 ftlbs at impact at 1000 yds. Will that kill an elk? Sure. It doesn't leave much room for error though... [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
7mm PRC Shorter Barrel Twist Rate
Top