ar 15 barrel

[furbymac]

what are your opinions of this barrl? should i look for something else? pros cons that i may be missing
AR-Stoner Barrel AR-15 223 Remington M4 Contour 1 in 7" Twist 16" Chrome Moly Matte Pre-Ban - MidwayUSA

 

[mvician]

what barrel?

 

[furbymac]

the one in the link

 

[ABN82]

shhhhh! It's the new stealth barrel!

 

[furbymac]

i have also noticed that most if not all barrels i see say .223 on them and can't seem to find any that say 5.56

 

[Limpy88]

dont get a 1-7 twist. will work with 55gr ammo which is the most available. but wont work as well as 1-8 or 1-9 twist for 55gr ammo.

 

[mvician]

dont get a 1-7 twist. will work with 55gr ammo which is the most available. but wont work as 1-8 or 1-9 twist for 55gr ammo.

 

[Limpy88]

By Corey Sattler (Webmanager@olyarms.com)

Here is the info I have collected for .223 twist ratios from various sources (including in-house testing & ammo manf. contacts).


1x7 - technically too tight of a twist for any .224 bullet widely available, including the 80 gr. Manufactured originally to stabilize SS109 and/or tracer ammo, but further military testing has shown other twists to be superior. Some of the very heavy custom stuff (87 gr?) may work well, but why????


1x8 - great twist for 69-80 gr bullets. Sierra once informed me that the perfect twist for their 80gr was 1x8.2xxxxx (blah blah blah big long engineers explanation followed).


1x9 - good all around twist ratio. Best suited for 52-69 gr, but either end of the envelope will be questionable.


1x10 - practically the same as 1x9, but favors the lighter side a little more.


1x12 - great for the 40-52 gr bullets. Most often found on bolt action rifles as their primary use is varminting. All right for the 55 gr, but not the best.


1x14 - if you want to understabilize the .224 bullet, use this twist. Useless except for tumbling effect it causes upon bullet impact. IMHO, better to shoot straight with a good HP bullet as your chances to hit are better and damage will most likely be greater also.


About the author: Mr. Sattler is the Law Enforcement Sales Manager and Archival Records Manager at Olympic Arms, Inc. in Olympia, WA and has been with the company since 1993. He is also a Reserve Deputy in a small Southwest Washington county Sheriff's Office.

 

[furbymac]

By Corey Sattler (Webmanager@olyarms.com) Here is the info I have collected for .223 twist ratios from various sources (including in-house testing & ammo manf. contacts).


1x7 - technically too tight of a twist for any .224 bullet widely available, including the 80 gr. Manufactured originally to stabilize SS109 and/or tracer ammo, but further military testing has shown other twists to be superior. Some of the very heavy custom stuff (87 gr?) may work well, but why????


1x8 - great twist for 69-80 gr bullets. Sierra once informed me that the perfect twist for their 80gr was 1x8.2xxxxx (blah blah blah big long engineers explanation followed).


1x9 - good all around twist ratio. Best suited for 52-69 gr, but either end of the envelope will be questionable.


1x10 - practically the same as 1x9, but favors the lighter side a little more.


1x12 - great for the 40-52 gr bullets. Most often found on bolt action rifles as their primary use is varminting. All right for the 55 gr, but not the best.


1x14 - if you want to understabilize the .224 bullet, use this twist. Useless except for tumbling effect it causes upon bullet impact. IMHO, better to shoot straight with a good HP bullet as your chances to hit are better and damage will most likely be greater also.


About the author: Mr. Sattler is the Law Enforcement Sales Manager and Archival Records Manager at Olympic Arms, Inc. in Olympia, WA and has been with the company since 1993. He is also a Reserve Deputy in a small Southwest Washington county Sheriff's Office.

what about for 5.56 which has a little more umph behind it

 

[Limpy88]

what about for 5.56 which has a little more umph behind it

the 5.56 is still a .224 bullet. even with the higher pressures i would say that the listing are still correct. but dont know the math for that one

 

[BloodEclipse]

I'm pretty sure barrel length has something to do with this as well.
A 1 in 7 in a 16" doesn't produce as much spin as in a 20" or 24"

 

[Limpy88]

"A common argument I hear from disbelievers revolves around some sort of belief that the twist rate must relate to the barrel length. This fallacy tries to say that since the twist rate of my .308 700 PSS is 1 in 12″, the barrel must be cut to a length in multiples of 12 inches in order for the bullet to spin properly. This is absurd. If this was true, Remington would never ship the PSS from the factory with a 26 inch barrel. And for that matter, a 1911 style .45 with a twist rate of 1in 16″ would have a 16″ barrel in order to be able to hit the target."

got that from here
GPS Sniper School Blog Archive Sniper Rifle Barrel Length

the total length of the barrel does nothing to change spin.

 

[BloodEclipse]

"A common argument I hear from disbelievers revolves around some sort of belief that the twist rate must relate to the barrel length. This fallacy tries to say that since the twist rate of my .308 700 PSS is 1 in 12″, the barrel must be cut to a length in multiples of 12 inches in order for the bullet to spin properly. This is absurd. If this was true, Remington would never ship the PSS from the factory with a 26 inch barrel. And for that matter, a 1911 style .45 with a twist rate of 1in 16″ would have a 16″ barrel in order to be able to hit the target."

got that from here
GPS Sniper School Blog Archive Sniper Rifle Barrel Length

the total length of the barrel does nothing to change spin.

I disagree. The more time in the twist under pressure the more effect the twist rate has.
If what you are quoting is true shouldn't sniper rifles be more accurate in say 9" barrels?
9" barrels have lower amounts of flex.

 

[Limpy88]

but at 9" you lose your velocity of the bullet effecting your range.


"Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:
MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps."
223 and 5.56 have any where between 3200fps to nearly 3900fps. start putting distant and the +/- of fps multipy greatly at impact of long range. thouse effecting the bullet powering through the air and fighting off direction changes



this is just a side note and a though that popped into my head.
with a 9" barrel you could possibly load a slow burning pistol powder and get the same results. as a full length barrel and rifle power

 

[BloodEclipse]

While looking for a twist rate\length comparison, I happened across this.

Bullets must have enough spin (RPM) when leaving the bore in order to fly true. Remember bullets begin to slow down (in RPM and velocity) from the moment they leave the bore so they must have enough spin from the start so that they remain spinning enough to fly true over the course of their trajectory otherwise if they arent spinning enough they will start to wobble off course which can result in a complete miss. (Remember misses are bad.)

Barrel twist rates are calculated using the caliber of the projectile and the length of the projectile. Most think in terms of weight of the projectile that determines twist rate but it is really the length. And in general terms the longer the bullet given the same caliber the more it will weigh but the truth is you could have two bullets that weigh the exact same amount but if one has an aluminum core it will be longer than the one with a lead core so the lighter bullet BECAUSE it is longer will require a tighter twist rate than the heavier/shorter one will.

The M16 started off with a 1x14 twist which is enough to shoot 55 grain bullets as long as the temperature of the air was above freezing. If the temp was below freezing the air density was such that the 1x14 twist was too slow and the bullet lost its spin too fast resulting in misses.

So the military changed the rate to 1x12 which solved the problem.

Then comes along the SS109/M855 62 grain round which since it is a longer bullet (because it is heavier) requires a 1x10 to stabilize. Problem was the tracer ammo M856 is even longer than the ball round of the SS109/M855 ammo cause they packed it with enough tracer compound so the bullet would trace all the way out to 800 meters which it almost twice as far as the older tracer ammo that burnt out at around 450 meters. Consequently this newer tracer ammo is a LONG bullet and requires a 1x6 twist rate. So the military compromised on a 1x7 twist rate for the new ammo.

Shorter (which USUALLY means lighter) bullets can be fired in barrels with tighter twist rates than in necessary but longer (which USUALLY means heavier) bullets cannot be shot in barrel twist rates that are slower than what they need. So the most versatile barrel twist rate is one that is tighter as it will shoot all bullet lengths/weights.

An example of what happens when uses a longer/heavier bullet in a too slow twist rate is shooting a SS109/M855 62 grain bullet in a 1x12" twist barrel. What will happen is right around 100 meters the bullet has lost too many RPM's and will actually start flying end over end - with horrible accuracy. The bullet may strike "sideways" - which is called "key-holing" - leaving a sideways imprint of the bullet. Hitting a body with a "key-holing" bullet aint bad - the bad part is the bullet won't go where it was aimed - so you only hit with a "fluke". Since our goal is to hit when we are aiming at something - key-holing is BAD. MIssing is WAY TOO easy with bullets that fly true - missing is almost garaunteed with bullets that don't fly true.

Bushmaster which was really the first company to start building ARs in a big way looked at the available ammunition back in the 80s when they started and back then 62 grains was heavy for .223s. Well the 62 grain lead projectile only needs a 1x10 twist to stabilize and since some 68 and even 69 grain projectiles were on the horizon they figured what the heck lets have our barrels be 1x9 twist. No one is going to be shooting heavier/longer bullets than 69 grains so 1x9 twist will be fine. Remember back then most bullet weights/lengths were in the 40-55 grain area.

Bushmaster soon became the leader in ARs and when more and more companies came on board they followed the leader and had their twist rates be 1x9 also which UNTIL the heavier bullets came along just a few years ago worked out just fine.

Now advance forward to just a few years ago when the war on terror started in earnest. The 62 grain bullet wasnt cutting the mustard. Due to different manufacturing techniques of bullet manufacturers some lots of the M855 wont fragment they way some other lots of M855 will and we all know that if the bullet doesnt fragment it doesnt work as well as when it does fragment. Also the range at which it will fragment is less than 200 meters. Couple this with the fact that the M855 bullet since it has a lead and steel core can NEVER be as accurate as a bullet that has an all lead core making distant sniper type shots a lot harder.

So SpecOps units started looking for a different bullet. (This is what started the ill fated attempt of the 6.8 SPC.) The military match shooters at the time were dominating the shooting matches using bullets that were 75-77 grains in weight. These bullets would allow our boys to make shots out to 600-700 meters with confidence of a hit cause they are extremely accurate bullets. What the SpecOps boys found out that in addition to being accurate these heavy bullets FRAGMENTED when they hit most water based mediums (bodies). And they fragmented with much more vigor than the 62 or even the 55 grain bullets cause since they were heavier/longer they had more material to fragment with! AND they are fragmenting at ranges far in excess of 200 meters.

These heavier bullets are doing such a good job that the 6.8 has since died on the vine.

So if one is getting a new AR or just a new barrel for SHTF purposes it would be my advice to a 1x7 twist barrel. The 1x7 twist will allow you to shoot ALL 55 grain ammo, 62 grain ammo and the 75 or 77 grain ammo. What you wont be able to shoot is the thin jacketed 40 grain ammo but no one would use that for SHTF purposes anyway! In other words you lose NOTHING by going to the 1x7 twist barrel but you GAIN the versatility of being able to use ANY fighting bullet made for the 5.56 family of firearms. So my question would be WHY LIMIT YOURSELF?? You may not have any of the 75 or 77 grain ammo - but why close the door on EVER using it?? Think in these terms - more and more LE units are moving to these rounds - the whole US military is looking at these rounds (because of the great success the SpecOps community is having with these rounds) - so this ammo is only going to be more prevalent as time goes on. DONT GET A NEW BARREL/UPPER that cant shoot these new rounds or you may live to regret it!

If your barrel has a 1x12" twist - you are limited to 55 grain ammo.
If your barrel has a 1x9" twist - you can shoot either the 55 grain or 62 grain (actually up to 69 grains reliably)
If your barrel has a 1x7" twist - you can shoo the 55 grain, 62 grain, 75 and 77 grain - even all the way up to 80 grains reliably

As far as ammo choices:
First choice BY A LONG MARGIN would be the 75 or 77 grain ammo it fragments beautifully from point blank out to many hundred meters.

Second choice would be M193 or equivalent 55 grain ammo if fragments reliably from point blank to around 150 +/- meters.

DISTANT third choice would be the SS109/M855 62 grain ammo which is not a reliable fragmenting round at any range.


Hope this helps,

cheers

tire iron

http://mscg.yuku.com/topic/1409/t/AR15-barrel-twist-rates-which-is-best.html?page=1

 

[BloodEclipse]

but at 9" you lose your velocity of the bullet effecting your range.


"Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:
MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps."
223 and 5.56 have any where between 3200fps to nearly 3900fps. start putting distant and the +/- of fps multipy greatly at impact of long range. thouse effecting the bullet powering through the air and fighting off direction changes



this is just a side note and a though that popped into my head.
with a 9" barrel you could possibly load a slow burning pistol powder and get the same results. as a full length barrel and rifle power

I was surprised that it is the length of the bullet and not it's weight that has the most effect from twist rate.

I agree with you on the velocity.

 

[Limpy88]

from your post i would derive that 75-77gr ammo is the most accurate in a 1-7 twist barrel.

from other sources 50-60gr ammo is more accurate in 1-8/1-9 ammo.

the cheapest box of 20 for 75-77 gr ammo is roughly $17 & not as readily avaible
the cheapest box of 20 for 55gr ammo is $8 and can be found anywhere.

1-7 twist you can shoot any thing. but to be extremely accurate is pricey.

since the op didnt state his intentions i would say that he can weigh in what he wants from both of our inputs.

 

[fireball168]

what are your opinions of this barrl? AR-Stoner Barrel AR-15 223 Remington M4 Contour 1 in 7" Twist 16" Chrome Moly Matte Pre-Ban - MidwayUSA

It is a $114 RETAIL barrel. I'd be surprised if Larry was paying over $50 for them.

That said, as with most of Midway's "house brand" products, I wouldn't expect much.


This is 10 times the barrel as that one, check around - you may find somebody with them in stock. Get on Brownells backorder list if nothing else, they'll take care of you.

DANIEL DEFENSE : AR-15/M16 M4 BARREL - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools

 

[slow1911s]

You can get this for under $200 - 1x8, mid-length gas system, .223 Wylde chamber

Wilson-Nordic AR Rifle Barrel, Stainless 16"

If you want to spend another $100, they sell a Lilja with the same specs.

 

[furbymac]

im kinda spining in circles with all this info ahhh. but anyways i appreciate it all. but the reall issue i am having is not the twist rate it is finding one for 5.56 i have found very few that say they were chambered for 5.56 i understand that they are still the same caliber bullet but i also has read that the 5.56 has a higher presser so i am assuming that the chamber would have to be reinforced a little more to be able to handle the higher pressure. but at the same time i can't find a bcg. labeled for 5.56 at all they are all .223 so i am assuming again that the only part that really matters is the chamber