Twist Rate
02-23-2015, 06:26 PM
#1
Nontypical Buck
Thread Starter
Join Date: Feb 2003
Location: Helena Mt USA
Posts: 1,834
Twist Rate
So I won a Stag AR-15 Model 2 from the NRA yesterday. I have never owned an AR before and know very little about them. Never the less, I'm super excited.
But I have been doing some reserch and am wondering what twist rate means. The twist rate is 1/9th button rifled. Its a .223/5.56
But I have been doing some reserch and am wondering what twist rate means. The twist rate is 1/9th button rifled. Its a .223/5.56
Last edited by stuckinthereeds; 02-23-2015 at 06:39 PM. Reason: more information given.
02-23-2015, 06:55 PM
#2
Nontypical Buck
Join Date: Feb 2003
Location: Eastern wv
Posts: 3,495
it'll probably shoot anything up to 70 grain bullets well, its one turn in 9 inches of barrel
here is the formula to determine bullet rpm
MV x (12/twist rate in inches) x 60 = Bullet RPM
so your shooting a 60 gr. bullet at 3100 fp
3100x(12/9=1.333) x 60=247,938 rpm's
should shoot any weight bullet well from 45 to 70 gr. as long as the bullets jacket can withstand the rpm's
RR
here is the formula to determine bullet rpm
MV x (12/twist rate in inches) x 60 = Bullet RPM
so your shooting a 60 gr. bullet at 3100 fp
3100x(12/9=1.333) x 60=247,938 rpm's
should shoot any weight bullet well from 45 to 70 gr. as long as the bullets jacket can withstand the rpm's
RR
02-23-2015, 08:44 PM
#3
Giant Nontypical
Join Date: Dec 2007
Location:
Posts: 5,130
Ridge explained it well..........here is some additional information;
http://www.gunnersden.com/index.htm....ist-rates.html
http://www.gunnersden.com/index.htm....ist-rates.html
02-24-2015, 06:42 AM
#5
Nontypical Buck
Join Date: Oct 2009
Location: Kansas
Posts: 3,894
Wait... Let me rephrase myself...
I like my RIGHTS too much...
