Mini-14 Twist Rate & Bullet Weight Compatibility: Expert Advice

Question
QUESTION: The twist on my mini-14 (.223 rem) is 1 in 9.  Is this sufficient for 75 grain bullets, or should I stay with the lower weights?  Thanks much.

ANSWER: I would not go above 69 grain bullets,
62 grain is optimal.

---------- FOLLOW-UP ----------

QUESTION: Thanks again.  My original question was more specific than I intended.  Do you have a reference that explores the relationships among bullet weight, twist, bullet diameter, and initial bullet velocity in-barrel along with the down-range consequences of various combinations?  Many thanks.  PS - Your Web site no longer exists, according to my browser.  :-(


Answer
Hi,

Here is an overview of ballistics.
http://www.rifleshootermag.com/shooting_tips/ballistics_0303/
http://www.rifleshootermag.com/ballistics/ballistic-tables/
http://www.gunnersden.com/index.htm.rifle-cartridges-ballistics.html
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1257093

Here are some links to ballistics theory and science.
http://books.google.com/books?id=pX9Tzs7VuSoC&pg=PP1&dq=ballistics#v=onepage&q=&
http://www.snipercountry.com/hottips/TwistRate.htm
http://www.loadammo.com/Topics/July01.htm

Basically you want the effects twist rate on internal and external ballistics.
You can also get this ballistics software.
http://accurateshooter.wordpress.com/2007/10/31/sierra-upgrades-infinity-ballist
http://www.midwayusa.com/viewProduct/?productNumber=251744
http://kwk.us/twist.html

Most reloading manuals will cover this topic somewhat.

I really need to redo the website info, its long gone.
I been here since 1998 and really haven't updated my profile.
I really need to get around to doing that.

feel free to ask follow ups

pez