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trg-s338
05-31-2011, 9:35 PM
Is there really no one that manufactures a quality 1:8 twist CHROME LINED barrel for the AR 15?

blazeaglory
05-31-2011, 9:37 PM
why when you can get a 1:7? are you really planning on shooting anything less than 55grain?

Colt-45
05-31-2011, 9:40 PM
Is there really no one that manufactures a quality 1:8 twist CHROME LINED barrel for the AR 15?

Noveske, top of the line quality but it's a 20" barrel.

dieselpower
05-31-2011, 10:02 PM
Is there really no one that manufactures a quality 1:8 twist CHROME LINED barrel for the AR 15?

Armalite. why do you want chrome lined and 1:8? seems counter productive...

mlevans66
05-31-2011, 10:07 PM
BCM

RMTactical
05-31-2011, 10:13 PM
Armalite. why do you want chrome lined and 1:8? seems counter productive...

Please, elaborate! :)

dieselpower
05-31-2011, 10:20 PM
Please, elaborate! :)

Wow, you want to learn or you think you are going to flame me. either way this will be fun...

To chrome a rifling you have to first oversize it, then fill that in with chrome. It decreases its accuracy over all. The chrome lining can not be kept to the same tolerance as a straight cut rifling can.

The same goes for button rifling. Its not as accurate as cut.

Heres a couple links to read on. If you need more I can give them to you. warning, this is actual tech stuff and most people just go zombie brain dead and close the page...icky reading and learning stuff...
http://www.border-barrels.com/articles/bmart.htm
http://answers.yahoo.com/question/index?qid=20080323154203AAm3tzi

So the 1:8 is meant as an accuracy build, but then to do a chrome over that defeats the 1:8. You can get the same accuracy out of a 1:7 or 1:9.
The best use of a 1:8 twist would be a SS barrel, not a chrome moly with chrome lining.

blazeaglory
05-31-2011, 10:26 PM
i knew that was gonna happen

patriot_man
05-31-2011, 11:35 PM
dieselpower hit it right on.

1:8 twist barrels are usually going to be all SS barrels that are built for accuracy not necessarily durability.

If I recall correctly when I ordered my Lilja SS barrel I remember where was an option for a chrome-moly version which was cheaper. Might be worth looking at.

Hoop
05-31-2011, 11:42 PM
Is there really no one that manufactures a quality 1:8 twist CHROME LINED barrel for the AR 15?

Um, WHY?

Heiko
05-31-2011, 11:43 PM
dieselpower hit it right on.

1:8 twist barrels are usually going to be all SS barrels that are built for accuracy not necessarily durability.

If I recall correctly when I ordered my Lilja SS barrel I remember where was an option for a chrome-moly version which was cheaper. Might be worth looking at.

This is how LaRue's 1:8 barrel is - stainless steel, no chrome.

waddachump
06-01-2011, 6:31 AM
Green mountain makes a 1:8 twist chrome lined m4 contour barrelhttp://www.gmriflebarrel.com/productdetail.aspx?id=GM-M4

sonnyt650
06-01-2011, 7:16 AM
Chrome-lining doesn't decrease precision as much as commonly stated, and I'll take the increased life of a barrel over the loss in precision. My numbers: my chrome-lined 16" 1:9 Bushmaster heavy barrel easily shoots sub MOA groups with Hornady 52 grain BTHP, other than finding the right bullet no load testing done (3 inch groups with 75 grain BTHP :(). By comparison I can't get a chrome-lined 20" 1:7 YHM heavy barrel to consistently print groups smaller than 1.5" with Hornady 75 grain BTHP, so in my case something else contributes more to lost precision.

tenpercentfirearms
06-01-2011, 7:18 AM
I think CMMG does some 1:8 chrome lined barrels. Check it out as I can't recall for sure.

bwiese
06-01-2011, 9:15 AM
Is there really no one that manufactures a quality 1:8 twist CHROME LINED barrel for the AR 15?

Last time I checked, CMMG's 18" SPR barrels are 1:8" twist. They have a tapered "MedCon" profile,
which means they're stiff/wide under the handguard and begin tapering to a somewhat smaller bbl
diameter as you go outward. This allows a nice stiff barrel and yet balances much better than an HBAR
bbl.

Mine shoots very well, but I'd rather have 1:7" for shooting 77gr SMK Fed GoldMedal Match.

The accuracy of a chrome-lined barrel is more due to the mfgr's reject vs acceptance rate than anything.
The FN SPR 308 bolt gun has a chrome-lined barrel and is capable of same-hole groups.
The Colt M4A1 HB barrel (1:7" twist, chromed, not thinner under handguards) is known to be very accurate too.

Most people do not have the ability to shoot the difference btwn a good chromed bbl and a better-accuracy non-chromed bbl.
Yet the chromed bbl will stay within its tolerances long after the non-chromed one starts to deviate (esp due to chamber erosion).

I'd chrome-line my intestines if I could.

(I'd REALLY love to get a Stellite-lined AR bbl, but no one makes 'em....)

RMTactical
06-01-2011, 1:44 PM
So the 1:8 is meant as an accuracy build, but then to do a chrome over that defeats the 1:8. You can get the same accuracy out of a 1:7 or 1:9.
The best use of a 1:8 twist would be a SS barrel, not a chrome moly with chrome lining.

Why do you speak opinions like they are facts?

chead
06-01-2011, 1:53 PM
Can someone explain the ballistic properties of barrel twist (and associated bullet grain)? I honestly just don't have a good grasp of it.

qaz5109
06-01-2011, 2:12 PM
people need to stick to the question not what they think matters