Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
11/22/2017 10:05:29 PM
3/10/2017 7:27:01 PM
Posted: 9/24/2004 5:39:58 PM EST
This has bothered me as the old saying goes, don't fix what aint' broken. Why do Bushmaster and other AR/barrel makers use 1/9 when 1/7 twist is good enough? It sure is good enough for military purposes. I'm talking general purpose 1/9 twist. Obviously there are varminter variants which would warrant 1/9, and then the match people like 1/8. But by and large it's been settled down to 1/9 or 1/7 for the general purpose barrel makers. Is 1/9 barrel cheaper to manufacture or something?
Link Posted: 9/24/2004 5:43:31 PM EST
Link Posted: 9/24/2004 5:45:47 PM EST
Bushmaster says they believe that 1/9 will accept a wider range of bullet weights/styles. I assume it's cheaper to focus on one twist rate.
Link Posted: 9/24/2004 5:58:38 PM EST
[Last Edit: 9/24/2004 5:59:50 PM EST by archad]
I can shoot the 77 OTM in my 16" AR with a 1/9 twist and Kill a Bear
Link Posted: 9/24/2004 6:20:09 PM EST
For the longest time the heavy stuff was relegated for match use. Most of the ARs out there aren't match rifles. Then the heavy stuff started gaining ground as a legitimate anti-personnel round. By that time most of the mfg's had already settled in on 1 in 9" for "all purpose" use or slower twists for varmint applications.

1 in 9" does nicely with bunches of laods, easily handling everything up to 69 grains. With some luck, they can work for 75/77 grain loads, but I still contend it's kind of a hit-or-miss proposition. Also, it can work in 1 in 9" longer barrels, but in the carbine length, you are stretching things a bit. Maybe in time BM will offer faster twist carbine barrels, who knows.
Link Posted: 9/24/2004 6:20:16 PM EST
Bushmaster also says that any or all M16 parts added to an AR15 (such as a M16 carrier without any other M16 parts) is also automatically considered a machinegun?

Yep, Bushmaster is your one stop shop for accurate AR information all right! LOL
Link Posted: 9/24/2004 6:33:46 PM EST
[Last Edit: 9/24/2004 6:52:03 PM EST by A_Free_Man]
Also agreeing with Jmart, shooting the extremely heavy projectiles, 77-80 gr, is a relatively new thing. The 1-7 twist was a NATO specification, but many had felt this was unnecessarily fast. The 1-9 twist was, for a long time, felt to be a better twist for most bullet weights in most conditions for a general purpose barrel. And this has been the case for more than 20 years.

Others were doing 1-9 when Bushy was still only making their original "Bushmaster" rifle (non-AR type that was not very well regarded).
Link Posted: 9/24/2004 6:37:26 PM EST
I emailed Bushmaster and I got a reply that they do make 1/7 carbine barrels but in 14.5 and they offer M4 profile or HBAR.I was quoted these prices and told to ask specificaly for it when I ordered.$220 for a barrel only assembly and $250 for a complete assembly with $30 extra for the phantom bringinit to $280 for the assembly wich I dont mind paying because colt ones are $400 or more and you cant always get 14.5.Bushmaster same quality but cheaper and Im ordering a barrel next week for my next build.
Link Posted: 9/24/2004 6:42:58 PM EST

Originally Posted By A_Free_Man:
Shooting the extremely heavy projectiles, 77-80 gr, is a relatively new thing. The 1-7 twist was a NATO specification, but many had felt this was unnecessarily fast. The 1-9 twist was, for a long time, felt to be a better twist for most bullet weights in most conditions for a general purpose barrel.



Gee, I thought Bushmaster was the forerunner when it came to civilian MIL Spec type rifles/parts

LOL
Link Posted: 9/24/2004 8:01:48 PM EST

Originally Posted By AKM:
Bushmaster also says that any or all M16 parts added to an AR15 (such as a M16 carrier without any other M16 parts) is also automatically considered a machinegun?



Uh, yeah. Putting an M16 bolt carrier in your gun, with no other M16 parts, will make you a felon. This is one of the special rulings applying only to AR15s.

Please see:

www.atf.gov/pub/fire-explo_pub/geninfo.htm

And I quote:

In order to avoid violations of the NFA, M16 hammers, triggers, disconnectors, selectors and bolt carriers must not be used in assembly of AR-15 type semiautomatic rifles, unless the M16 parts have been modified to AR-15 Model SP1 configuration. Any AR-15 type rifles which have been assembled with M16 internal components should have those parts removed and replaced with AR-15 Model SP1 type parts which are available commercially. The M16 components also may be modified to AR-15 Model SP1 configuration.

Link Posted: 9/24/2004 8:15:31 PM EST
just changing w/ the times
Link Posted: 9/24/2004 8:17:20 PM EST
Heavy bullets are a recent development, after the 1/9 had become popular.
Link Posted: 9/24/2004 8:58:18 PM EST
Does that ATF ruling about M-16 parts mean ALL the parts together or just any SINGLE part? Specifically, the M-16 bolt carrier.

thanks,
Ron
Link Posted: 9/24/2004 9:13:59 PM EST
[Last Edit: 9/24/2004 9:38:00 PM EST by azeagle]
Directly from the ATF website. But remember that it is a website and saying you got the information from the ATF website may not be a legal defense if charged with a crime.

http://www.atf.gov/firearms/faq/faq2.htm#m1

Some examples of the types of firearms that must be registered are:
Machineguns;
The frames or receivers of machineguns;
Any combination of parts designed and intended for use in converting weapons into machineguns;
Any part designed and intended solely and exclusively for converting a weapon into a machinegun;
Any combination of parts from which a machinegun can be assembled if the parts are in the possession or under the control of a person;
Silencers and any part designed and intended for fabricating a silencer;
Short-barreled rifles;
Short-barreled shotguns;
Destructive devices; and,
"Any other weapons."

In other words, buy M-16 parts at your own risk.
Link Posted: 9/24/2004 9:23:25 PM EST
[Last Edit: 9/24/2004 9:31:21 PM EST by gotm4]

Originally Posted By -Duke-Nukem-:

Originally Posted By AKM:
Bushmaster also says that any or all M16 parts added to an AR15 (such as a M16 carrier without any other M16 parts) is also automatically considered a machinegun?



Uh, yeah. Putting an M16 bolt carrier in your gun, with no other M16 parts, will make you a felon. This is one of the special rulings applying only to AR15s.

Please see:

www.atf.gov/pub/fire-explo_pub/geninfo.htm

And I quote:

In order to avoid violations of the NFA, M16 hammers, triggers, disconnectors, selectors and bolt carriers must not be used in assembly of AR-15 type semiautomatic rifles, unless the M16 parts have been modified to AR-15 Model SP1 configuration. Any AR-15 type rifles which have been assembled with M16 internal components should have those parts removed and replaced with AR-15 Model SP1 type parts which are available commercially. The M16 components also may be modified to AR-15 Model SP1 configuration.




Just remember that the BATFE doesn't make or interpret the law they enforce it, the courts interpret the law. Yeah you 'might' get trouble just as one day monkeys 'might' fly out of my ass but if you're using a M16 carrier and your rifle fires no more than one round per trigger pull then it's still semi-automatic and you have nothing to worry about. 1x9 works well for most people who shoot 40-69gr ammo 1x7 was used by the military to be able to stabilize the militarys M856 tracer.
Link Posted: 9/24/2004 9:29:50 PM EST
The M16 bolt carrier discussion was covered extensively not too long ago. Any have a link? IIRC it boiled down to the fact that yes you're allowed to use an M16 bolt carrier as long as the rifle still only fires in semi
Link Posted: 9/24/2004 10:25:49 PM EST
Originally Posted By gotm4:

Just remember that the BATFE doesn't make or interpret the law they enforce it, the courts interpret the law. Yeah you 'might' get trouble just as one day monkeys 'might' fly out of my ass

Thats going to be awfully painful.

The BATF can make laws. Its called the Code of Federal Regulations. Those aren't created by Congress or the States and provide for monetoary fines as well as confinement.

CFR 27 Section 179.11 Meaning of terms page 1203

Words in the plural form shall include the singular, and vice
versa,

Definition of a Machine Gun

Machine gun. Any weapon which shoots, is designed to shoot, or can
be readily restored to shoot, automatically more than one shot, without
manual reloading, by a single function of the trigger. The term shall
also include the frame or receiver of any such weapon, any part designed
and intended solely and exclusively, or combination of parts designed
and intended, for use in converting a weapon into a machine gun, and any
combination of parts from which a machine gun can be assembled if such
parts are in the possession or under the control of a person.


Like I said. Buy M-16 parts at your own risk.
Link Posted: 9/24/2004 10:28:44 PM EST
M16 bolt carriers are not considered a conversion part and are 100% legal.
Link Posted: 9/24/2004 10:57:32 PM EST
Why put a M16 bolt in your gun, when an AR15 bolt will do just as well, and not get you in trouble with the ATF?
Link Posted: 9/24/2004 11:33:39 PM EST

Originally Posted By AKM:

Originally Posted By A_Free_Man:
Shooting the extremely heavy projectiles, 77-80 gr, is a relatively new thing. The 1-7 twist was a NATO specification, but many had felt this was unnecessarily fast. The 1-9 twist was, for a long time, felt to be a better twist for most bullet weights in most conditions for a general purpose barrel.



Gee, I thought Bushmaster was the forerunner when it came to civilian MIL Spec type rifles/parts

LOL



Someone's got a hard-on for Bushmaster.

Back on topic, 1 in 9" is almost ideal for 55gr bullets. In fact, the original SCHV designers wanted 1 in 10". The newer, heavier M855 and its associated tracer round was the reason for the switch to 1 in 7. Most folks in the civilian world shoot 55gr bullets, outside of match competition or varmint hunting. 1 in 9 will stabilize a wider variety of the bullets likely to be used by the average shooter.
Link Posted: 9/24/2004 11:37:39 PM EST

Originally Posted By warlord:
Why put a M16 bolt in your gun, when an AR15 bolt will do just as well, and not get you in trouble with the ATF?



My rifles came that way. And I would like to be able to put them on a rented or borrowed M16 lower when I can legally do so.
Link Posted: 9/25/2004 2:21:04 AM EST

Originally Posted By -Duke-Nukem-:

Originally Posted By AKM:
Bushmaster also says that any or all M16 parts added to an AR15 (such as a M16 carrier without any other M16 parts) is also automatically considered a machinegun?



Uh, yeah. Putting an M16 bolt carrier in your gun, with no other M16 parts, will make you a felon. This is one of the special rulings applying only to AR15s.

Please see:

www.atf.gov/pub/fire-explo_pub/geninfo.htm

And I quote:

In order to avoid violations of the NFA, M16 hammers, triggers, disconnectors, selectors and bolt carriers must not be used in assembly of AR-15 type semiautomatic rifles, unless the M16 parts have been modified to AR-15 Model SP1 configuration. Any AR-15 type rifles which have been assembled with M16 internal components should have those parts removed and replaced with AR-15 Model SP1 type parts which are available commercially. The M16 components also may be modified to AR-15 Model SP1 configuration.






oh, no, didn't we do this a million times already???
Link Posted: 9/25/2004 2:50:56 AM EST
[Last Edit: 9/25/2004 3:15:03 AM EST by gotm4]


We've gone over and over and over and over and over and over and wait a minute over this many times below is two of those times.

The legality of a M16 carrier should be tacked for the s so we don't waste bandwidth every month.


www.ar15.com/forums/topic.html?b=1&f=6&t=147440
www.ar15.com/forums/topic.html?b=1&f=6&t=259815



Link Posted: 9/25/2004 2:57:13 AM EST
Everyone knows that it is generally excepted that barrels with a 1/9 twist will perform the best with the widest range of (commercial) ammunition. That's why they use it.
Link Posted: 9/25/2004 4:08:28 AM EST
[Last Edit: 9/25/2004 4:11:36 AM EST by Mulliga]

specifically www.ammo-oracle.com/body.htm#twists

+1
Link Posted: 9/25/2004 10:16:16 AM EST
Thank you GOTM4, i was just looking for this picture to post...
Link Posted: 9/25/2004 10:41:26 AM EST

Originally Posted By AKM:
Bushmaster also says that any or all M16 parts added to an AR15 (such as a M16 carrier without any other M16 parts) is also automatically considered a machinegun?

Yep, Bushmaster is your one stop shop for accurate AR information all right! LOL



The highest quality AR-15 stuff in my cabinet is Bushmaster. This is fine with me. You are free to buy what you want, and that includes M-16 parts. You are also free to look for trouble you do not need. You'r rifles will still not outperform.
Top Top