Barrel stamped 8 mp 5.56 1/9?This is a discussion on Barrel stamped 8 mp 5.56 1/9? within the AR Talk forums, part of the Long Gun Talk category; I just bought a used Ar and the barrel is stamped as such....any help?...
 |
06-21-2012, 06:36 PM
|
#1
|
|
XDTalk Newbie
Member #: 46101
Join Date: May 2010
Location: Sarasota Fl, Nancy Ky
Posts: 11
|
Barrel stamped 8 mp 5.56 1/9?
 I just bought a used Ar and the barrel is stamped as such....any help?
__________________
JOHN 16:33
|
|
|
|
06-21-2012, 06:41 PM
|
#2
|
|
XDTalk 100 Member
Member #: 68820
Join Date: Jan 2012
Location: Arizona
Posts: 139
|
Quote:
Originally Posted by firemedic309
I just bought a used Ar and the barrel is stamped as such....any help? |
Bushmaster right?
Im pretty sure its a B and not a 8, Magnetic Particle tested barrel, it shoots a 5.56 caliber, and your barrel has a 1/9 rifling
Pics will help too.
|
|
|
|
|
06-21-2012, 06:46 PM
|
#3
|
|
XDTalk 60K Member
Member #: 14053
Join Date: Dec 2006
Location: NW Ohio
Posts: 63,094
|
The 8 is a B (for Bushmaster), MP stands for "magnetic particle", 1/9 means caliber 5.56mm, 1/9 indicates 1 inch twist in the rifling for every 9 inches of barrel length.
__________________
"What lies behind us and what lies before us are tiny matters compared to what lies within us". - Ralph Waldo Emerson
|
|
|
|
|
06-21-2012, 06:56 PM
|
#4
|
|
XDTalk Newbie
Member #: 46101
Join Date: May 2010
Location: Sarasota Fl, Nancy Ky
Posts: 11
|
Thanks the B and the MP where what I did not know.
It has a CMMG lower, A Bushmanster upper,Timmey trigger,Magpul ACS stock, YHM barrel gard, Rock river carry handle, ARMS silloet pop up front sight, Magpul ASAP all for $645.00... I have been waiting for a deal like this for a long time  
__________________
JOHN 16:33
|
|
|
|
|
06-21-2012, 07:21 PM
|
#5
|
|
XDTalk 500 Member
Member #: 72857
Join Date: Apr 2012
Location: Knoxville, TN
Posts: 733
|
Quote:
Originally Posted by slugger6
1/9 means caliber 5.56mm, 1/9 indicates 1 inch twist in the rifling for every 9 inches of barrel length.
|
Don't you mean 1/9 means 1 revolution of the bullet inside the bore for every 9 inches of barrel length?
|
|
|
|
06-21-2012, 08:43 PM
|
#6
|
|
XDTalk 2K Member
Member #: 71862
Join Date: Mar 2012
Location: Republik of Kalifornia
Posts: 2,097
|
Quote:
Originally Posted by LocoGringo
Don't you mean 1/9 means 1 revolution of the bullet inside the bore for every 9 inches of barrel length?
|
That is correct.
|
|
|
|
|
06-21-2012, 11:41 PM
|
#7
|
|
XDTalk 2K Member
Member #: 11014
Join Date: Jun 2006
Location: not California
Posts: 2,355
|
Quote:
Originally Posted by LocoGringo
Don't you mean 1/9 means 1 revolution of the bullet inside the bore for every 9 inches of barrel length?
|
There is one complete rotation (in the groove/land--ie: rifling) for every 9 inches of barrel.
Upon thinking about it more, the bullet rides in the groove in order to get its' spin, so I'm going to go ahead and admit I was partially wrong and the correct answer is both.
__________________
if you give them an inch, eventually they will be a ruler.
|
|
|
|
|
06-22-2012, 11:29 AM
|
#8
|
|
XDTalk 3K Member
Member #: 33132
Join Date: Jan 2009
Location: Buckeye AZ
Posts: 3,137
|
Quote:
Originally Posted by John A.
There is one complete rotation (in the groove/land--ie: rifling) for every 9 inches of barrel.
Upon thinking about it more, the bullet rides in the groove in order to get its' spin, so I'm going to go ahead and admit I was partially wrong and the correct answer is both.
|
"1/9 means caliber 5.56mm"
No, you were completly wrong, 1/9 has nothing to do with caliber. 1/9 has nothing to do with 1 inch, it is one revolution of the bullet for every 9 inches of barrel.
don
|
|
|
|
|
06-22-2012, 11:54 AM
|
#9
|
|
XDTalk 2K Member
Member #: 11014
Join Date: Jun 2006
Location: not California
Posts: 2,355
|
Quote:
Originally Posted by dglock
"1/9 means caliber 5.56mm"
No, you were completly wrong, 1/9 has nothing to do with caliber. 1/9 has nothing to do with 1 inch, it is one revolution of the bullet for every 9 inches of barrel.
don
|
Sorry, you must've quoted the wrong person. And if you read what I wrote, basically said what you did. 1 rotation of the bullet for every 9 inches of barrel.
I never said "1:9 means caliber 5.56"
5.56 would be the chamber dimensions
__________________
if you give them an inch, eventually they will be a ruler.
|
|
|
|
Lower Navigation
|
|
|
| Search tags for this page |
|
5.56 barrel twist, 8 mp 5.56, 8 mp 5.56 nato 1/9, 8 mp ar barrel, b mp 5.56 nato 1/9, b mp stamped on bushmaster barrel, barrel stamped 5.56mm, bushmaster barrel markings b mp 5.56 nato 1/9, bushmaster barrel mp8 barrel stamp, is an m&p barrel stamped wtih the twist, l mp 5.56 nato 1/9 barrel, mp stamped on ar, smith and wesson b mp 5.56 1:9, what does b mp 5.56 nato 1/9 mean, what does b mp stand for in ar15 barrels
|
| Thread Tools |
|
|
| Display Modes |
 Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
XDTalk Forums - Your XD/XD(m) Information Source!
»
Barrel stamped 8 mp 5.56 1/9?
