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Posted: 4/8/2008 11:27:32 PM EDT
Is there a downside to 1/7 twist as opposed to 1/9?
Link Posted: 4/8/2008 11:28:36 PM EDT
No.
Link Posted: 4/8/2008 11:44:43 PM EDT
Might be if you're using sub 50gr thin jacketed projectiles.
Link Posted: 4/9/2008 12:32:24 AM EDT
Yes.

The downside is that there aren't any AUG barrels made in 1/7.
Link Posted: 4/9/2008 12:39:22 AM EDT
WTF?  Why don't you spend the time to READ the responses to your threads?

www.ar15.com/forums/topic.html?b=3&f=118&t=372536

I already provided you a link offering more information on twist rates then you could use.
Link Posted: 4/9/2008 2:16:16 AM EDT
NO



Link Posted: 4/9/2008 9:31:04 AM EDT
height=8
Originally Posted By 325AIR:
WTF?  Why don't you spend the time to READ the responses to your threads?

www.ar15.com/forums/topic.html?b=3&f=118&t=372536

I already provided you a link offering more information on twist rates then you could use.




Trying to gather info from a lot of diff. sources
Link Posted: 4/9/2008 9:43:25 AM EDT
Probably doesn't shoot .22LR worth a shit
Link Posted: 4/9/2008 9:47:10 AM EDT
Go to the Ammunition forum and read the "tacked" Ammo Faq thread.....

mike
Link Posted: 4/16/2008 10:56:23 AM EDT
I read all about it in the ammo FAQs....said something about how 1/7 may over-spin some lighter ammo....


but like, Fed. FMJ is only 55g so would it be able to shoot that okay?

im just worried about not being able to shoot well unless i use big$ ammo all the time

i will be using a colt HBAR 20"
and a colt pencil 16"


both are 1/7 twist
Link Posted: 4/16/2008 5:13:29 PM EDT
It is GTG for most ammo.  Some of us even have shot 45 grainers with out them "spinning apart".  From how I understand it, it's the 40-45 grain ballistic tips that you could have troubles with.  Are you going to be shooting those?  I have 1/7's that like some of the lighter bullets.  In fact, one of my sayings is, "I've never met a barrel that didn't like the 52's".
Link Posted: 4/16/2008 8:49:00 PM EDT
will more than likely be shooting only the 55gr for recreation....hopefully those will hold up :)
Link Posted: 4/17/2008 5:16:58 AM EDT
this topic has always confused me on the AR15 milspec issue.  what the AR15 clan believe is usually completely the opposite of what the bench rest, target and varmit hunter believe when it comes to rifling twist.  the old milspec was a 1:9 for 55 gr bullets.   Most target/ varmit shooters for that round and a bit lighter choose a 1:12 rifling.  some even use that rifling in 223 to stabilize 64 grain bullets.  the milspec jumped to 1:7 for 62gr bullets.   again that is totally against what target / varmit shooters use,  as most find that a 1:10 to be the minimum for the high 60 class bullets and 1:7 twists are relegated to 80 to 90 grain bullets.  most target grade 223's are sold with 1:12 barrels from what i have seen.  the military chose the 1:7 twist to stabilize one particular load, but most outside the AR realm would concider it TOO much twist even for that round.  with a bullet the tiny frontal size of a .224 in, too much stability is not good when it comes to stopping power i would think.   its really hard to get a true picture of how the M-16 is really doing in combat for every web site that i find that praises its operation, i find another claiming its complete failure.
Link Posted: 4/17/2008 5:41:26 AM EDT

Originally Posted By 767fixer:
this topic has always confused me on the AR15 milspec issue.  what the AR15 clan believe is usually completely the opposite of what the bench rest, target and varmit hunter believe when it comes to rifling twist.  the old milspec was a 1:9 for 55 gr bullets.   Most target/ varmit shooters for that round and a bit lighter choose a 1:12 rifling.  some even use that rifling in 223 to stabilize 64 grain bullets.  the milspec jumped to 1:7 for 62gr bullets.   again that is totally against what target / varmit shooters use,  as most find that a 1:10 to be the minimum for the high 60 class bullets and 1:7 twists are relegated to 80 to 90 grain bullets.  most target grade 223's are sold with 1:12 barrels from what i have seen.  the military chose the 1:7 twist to stabilize one particular load, but most outside the AR realm would concider it TOO much twist even for that round.  with a bullet the tiny frontal size of a .224 in, too much stability is not good when it comes to stopping power i would think.   its really hard to get a true picture of how the M-16 is really doing in combat for every web site that i find that praises its operation, i find another claiming its complete failure.



Close, 1/7 was used because that is what the M249 used in order to stabilize the M856 tracer linked on the belts.  This keps rifle ammo and squad light autpomatic rifle ammo standardized.
Link Posted: 4/17/2008 5:55:18 AM EDT
NO
Link Posted: 4/17/2008 6:01:16 AM EDT

Originally Posted By 767fixer:
this topic has always confused me on the AR15 milspec issue.  what the AR15 clan believe is usually completely the opposite of what the bench rest, target and varmit hunter believe when it comes to rifling twist.  the old milspec was a 1:9 for 55 gr bullets.   Most target/ varmit shooters for that round and a bit lighter choose a 1:12 rifling.  some even use that rifling in 223 to stabilize 64 grain bullets.  the milspec jumped to 1:7 for 62gr bullets.   again that is totally against what target / varmit shooters use,  as most find that a 1:10 to be the minimum for the high 60 class bullets and 1:7 twists are relegated to 80 to 90 grain bullets.  most target grade 223's are sold with 1:12 barrels from what i have seen.  the military chose the 1:7 twist to stabilize one particular load, but most outside the AR realm would concider it TOO much twist even for that round.  with a bullet the tiny frontal size of a .224 in, too much stability is not good when it comes to stopping power i would think.   its really hard to get a true picture of how the M-16 is really doing in combat for every web site that i find that praises its operation, i find another claiming its complete failure.


Speaking strictly for myself here, I have serious doubts "you" have ever fired an AR15 out to the 1000 yard line, otherwise you would not have mis-stated the fact that target and varmint users prefer the slower twist and the lighter weight 223 bullets.

I have been pitchin 77grn SMKs from my 24" bbl'd CR6724 for dang near ten years now and IMO you are dead wrong w/ your assesment on what fodder and twist rates long range AR15 users are shooting.

It's the 21st century and your information/comments w/ regard to bullet weights and twist rates are way out of date.

mike
Link Posted: 4/17/2008 6:44:11 AM EDT
[Last Edit: 4/17/2008 6:47:09 AM EDT by 767fixer]

Originally Posted By mr_wilson:

Originally Posted By 767fixer:
this topic has always confused me on the AR15 milspec issue.  what the AR15 clan believe is usually completely the opposite of what the bench rest, target and varmit hunter believe when it comes to rifling twist.  the old milspec was a 1:9 for 55 gr bullets.   Most target/ varmit shooters for that round and a bit lighter choose a 1:12 rifling.  some even use that rifling in 223 to stabilize 64 grain bullets.  the milspec jumped to 1:7 for 62gr bullets.   again that is totally against what target / varmit shooters use,  as most find that a 1:10 to be the minimum for the high 60 class bullets and 1:7 twists are relegated to 80 to 90 grain bullets.  most target grade 223's are sold with 1:12 barrels from what i have seen.  the military chose the 1:7 twist to stabilize one particular load, but most outside the AR realm would concider it TOO much twist even for that round.  with a bullet the tiny frontal size of a .224 in, too much stability is not good when it comes to stopping power i would think.   its really hard to get a true picture of how the M-16 is really doing in combat for every web site that i find that praises its operation, i find another claiming its complete failure.


Speaking strictly for myself here, I have serious doubts "you" have ever fired an AR15 out to the 1000 yard line, otherwise you would not have mis-stated the fact that target and varmint users prefer the slower twist and the lighter weight 223 bullets.

I have been pitchin 77grn SMKs from my 24" bbl'd CR6724 for dang near ten years now and IMO you are dead wrong w/ your assesment on what fodder and twist rates long range AR15 users are shooting.

It's the 21st century and your information/comments w/ regard to bullet weights and twist rates are way out of date.

mike


first i was seperating target rifles from Ar-15 class rifles.  

so long range shooters are using lighter bullets?  did you miss read what i typed?   damn with the wind drift ?

will this help to what i was stating?  its even likley ar-15 based

www.odcmp.org/new_forum/topic.asp?ARCHIVE=true&TOPIC_ID=45353
Link Posted: 4/17/2008 7:01:27 AM EDT
[Last Edit: 4/17/2008 7:05:25 AM EDT by JJREA]

Originally Posted By 767fixer:

Originally Posted By mr_wilson:

Originally Posted By 767fixer:
this topic has always confused me on the AR15 milspec issue.  what the AR15 clan believe is usually completely the opposite of what the bench rest, target and varmit hunter believe when it comes to rifling twist.  the old milspec was a 1:9 for 55 gr bullets.   Most target/ varmit shooters for that round and a bit lighter choose a 1:12 rifling.  some even use that rifling in 223 to stabilize 64 grain bullets.  the milspec jumped to 1:7 for 62gr bullets.   again that is totally against what target / varmit shooters use,  as most find that a 1:10 to be the minimum for the high 60 class bullets and 1:7 twists are relegated to 80 to 90 grain bullets.  most target grade 223's are sold with 1:12 barrels from what i have seen.  the military chose the 1:7 twist to stabilize one particular load, but most outside the AR realm would concider it TOO much twist even for that round.  with a bullet the tiny frontal size of a .224 in, too much stability is not good when it comes to stopping power i would think.   its really hard to get a true picture of how the M-16 is really doing in combat for every web site that i find that praises its operation, i find another claiming its complete failure.


Speaking strictly for myself here, I have serious doubts "you" have ever fired an AR15 out to the 1000 yard line, otherwise you would not have mis-stated the fact that target and varmint users prefer the slower twist and the lighter weight 223 bullets.

I have been pitchin 77grn SMKs from my 24" bbl'd CR6724 for dang near ten years now and IMO you are dead wrong w/ your assesment on what fodder and twist rates long range AR15 users are shooting.

It's the 21st century and your information/comments w/ regard to bullet weights and twist rates are way out of date.

mike


first i was seperating target rifles from Ar-15 class rifles.  

so long range shooters are using lighter bullets?  did you miss read what i typed?   damn with the wind drift ?

will this help to what i was stating?  its even likley ar-15 based

www.odcmp.org/new_forum/topic.asp?ARCHIVE=true&TOPIC_ID=45353

\
Why are you seperating target rifles from AR's?  Your link showed info of a bunch of people "target" shooting with AR's.

If Bench rest shooters are only shooting at 100 yards, then they are fine with lighter projectiles and don't need a heavier twist.  I don't know, I'm not a Bench Rest competitor and don't follow them.  I know that some people get away with shooting heavier bullets out of 1/9's.  I personally have never heard of anyone shooting an 80 grain out of a 1/9 in competition.  Alot of the HiPower shooters with purpose built AR's shoot 1/8.  That's competing at 2,3 and 6 hundred yards.  

I'm not sure what you are arguing about.  Yes a slower twist may exhibit better accuracy for Bench Rest shooters using lighter bullets.  Whoop de ding.  But if you want a GP rifle, which the AR is an excellent choice for this.  Home defense, hunting, plinking, whatever, a faster twist is not going to be a detraction.  It would be preferred.  In case you do want to shoot something heavier.

I don't know why people have such a problem with this, but whenever this subject comes up, the slow twist proponents come out of the woodwork.  Just because remington and whoever make some of their heavy barreled bolt guns with a 1/12, doesn't mean that it is  the best twist for everything.  Those are designed for varminters shooting lighter bullets.  If you look at all the other bolt guns that are in the tactical design, they at least use a 1/9.  If that doesn't tell you something.  I don't know what does.  Personally for me,  anything between 1/9 to 1/7 is a good idea for an AR.  I wouldn't poo poo a 1/12 if 55's were the only thing I was ever going to shoot either.  But it is what it is.  A 1/7 isn't going to render the lighter bullets useless.  

As far as stopping power and how it works in combat, I don't think the twist is going to change any of that.  If you are saying a lighter bullet with a lighter twist is better for combat, I'd say that's probably not completely true.  I think the best results are with the heavier MK262 ammo that would a require a faster twist than 1/12 since it is 77 grains.
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