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
Reloading
300 Win Mag reloading advise.
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="Hugnot" data-source="post: 2499471" data-attributes="member: 115658"><p>The method used in my spread sheet is the Miller Sg (stability) estimator. I use this before buying bullets. The recommended Sg is 1.4 & above. This is an estimator - the math may be seen on the top line. This method is also used by Berger & JBM on their on-line estimators.</p><p></p><p>I have had satisfactory results with bullets having Sg's of under 1.5 but this is at 3000 ft altitude. A .224 bullet having a Sg of 1.22 wth a 9 twist did not did not shoot well, as expected - eliptical bullet holes also.</p><p></p><p>The Hornady 4DOF process is avalble on-line & stability numbers are under the "Gyro" column gradually increasing with range. Hornady reccommends a starting "Gyro" value of 1.5 or above. A big bullet "library" having many bullets, some not Hornady, is included for calculator use.</p><p></p><p>This stuff is sort of academic but can prevent buying a high priced box of bullets that won't work. Bullet performance varies with conditions like at sea level on a cold day to mile-high on a warm day.</p><p></p><p>Measuring twist is easy. Tape on cleaning rod, tight patch on jag, lighly oiled bore, drag rod having patch out of bore watching for complete revolution of rod as indicated by mark on tape then measure distance for one revolution.</p></blockquote><p></p>
[QUOTE="Hugnot, post: 2499471, member: 115658"] The method used in my spread sheet is the Miller Sg (stability) estimator. I use this before buying bullets. The recommended Sg is 1.4 & above. This is an estimator - the math may be seen on the top line. This method is also used by Berger & JBM on their on-line estimators. I have had satisfactory results with bullets having Sg's of under 1.5 but this is at 3000 ft altitude. A .224 bullet having a Sg of 1.22 wth a 9 twist did not did not shoot well, as expected - eliptical bullet holes also. The Hornady 4DOF process is avalble on-line & stability numbers are under the "Gyro" column gradually increasing with range. Hornady reccommends a starting "Gyro" value of 1.5 or above. A big bullet "library" having many bullets, some not Hornady, is included for calculator use. This stuff is sort of academic but can prevent buying a high priced box of bullets that won't work. Bullet performance varies with conditions like at sea level on a cold day to mile-high on a warm day. Measuring twist is easy. Tape on cleaning rod, tight patch on jag, lighly oiled bore, drag rod having patch out of bore watching for complete revolution of rod as indicated by mark on tape then measure distance for one revolution. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
300 Win Mag reloading advise.
Top