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Posted: 1/9/2005 2:46:46 PM EDT
[Last Edit: 1/9/2005 3:12:10 PM EDT by Ghost-1]
Okay I have tried to find the answer my self and keep getting nowhere, I am trying to find out the differance in the CHROMED LINED, CHROME MOLY and other type of AR barrels.

What is it that makes one better than the other and which is easier to mantain and which is more accurate for regular target shooting and self defense and any type of 3 gun matches.

Also what is the best type of ammo to use with the 1/7 twist the 1/9 twist and 1/8 twist also what is the most popular twist rate and which would you use for what.

Like I said earlier I just can't seem to find the answer that I am looking for and it starts to get confussing when you realy start getting into it all.
Link Posted: 1/9/2005 4:12:14 PM EDT
Chromelined barrels are steel barrels that have the bores lined with chrome. Chromelined barrels are easier to clean, but may be slightly less accurate than an unlined barrel.

Chrome Moly barrels are named after the material they are made of.

Slower twist rates (1-in12, etc.) require lighter bullets such as 55-grain. Faster twist rates (1-in-7, etc.) can handle heavier bullets.
Link Posted: 1/9/2005 4:22:56 PM EDT
Okay so a chromoly barrel is not lined, so how good are chromoly barrels and how accurate are they? How hard are they to clean?

If you get a chromoly barrel with a 1/9 twist what grain bullet's can you use with it and what are the best one to use for that type of barrel?
Link Posted: 1/9/2005 4:48:33 PM EDT

Originally Posted By Ghost-1:
If you get a chromoly barrel with a 1/9 twist what grain bullet's can you use with it and what are the best one to use for that type of barrel?



From the Ammo Oracle:

Q. What twist rate do I want for my rifle?

A. Probably 1:9, but it depends on what kind of bullets you intend to shoot.

Special purpose rifles often have uncommon twist rates. For example, if you are building a varmint rifle and want to shoot the short 35 grain, 40 grain, and 50 grain bullets, a 1:12, or even 1:14 twist would be best. On the other hand, long range High Power shooters often select 1:8, 1:7.7, 1:7, or 1:6.5-twist barrels to stabilize the long 77, 80 and even 90 grain bullets used for 1,000 yard competition. Additionally, new testing of heavier rounds (68-77 grains) seems to show that they perform very well in simulated tissue and may be a better defensive choice than 55 grain or 62 grain rounds. The majority of shooters, though, typically shoot bullets of 50 to 69 grains in weight (note that the 62gr SS-109/M855 bullet is as long as a 71 grain lead core bullet) and should select 1:9 twist barrels. At typical .223 velocities, a 1:9 twist will stabilize bullet lengths equivalent to lead-core bullets of 40 to 73 grains in weight.

1:12 twist rifles cannot stabilize SS-109/M855 bullets and 1:7 twist rifles are slightly less accurate with lighter bullets and will often blow apart the thin jackets of lightweight varmint bullets. The 1:7 twist is used by the military to stabilize the super-long L-110/M856 tracer bullet out to 800 yards, but unless your plans include shooting a significant amount of M856, the 1:9 twist rate is better suited for general use.

There is, of course, an exception: if you want to use loads utilizing the heavier, 75-77 grain match bullets currently used by Spec-Ops troops and other selected shooters, you'll want a 1:7 twist barrel. Although military loadings using these bullets are expensive and hard to get, some persistent folks have managed to obtain a supply, and will need the proper barrel twist to use them. Anyone who foresees a need to shoot this ammo should consider a 1:7 twist barrel.
Link Posted: 1/9/2005 5:00:02 PM EDT
The Ammo Oracle - it is your friend.
Link Posted: 1/9/2005 5:06:42 PM EDT
[Last Edit: 1/9/2005 5:07:05 PM EDT by Ghost-1]

Originally Posted By M4Madness:

Originally Posted By Ghost-1:
If you get a chromoly barrel with a 1/9 twist what grain bullet's can you use with it and what are the best one to use for that type of barrel?



From the Ammo Oracle:

Q. What twist rate do I want for my rifle?

A. Probably 1:9, but it depends on what kind of bullets you intend to shoot.

Special purpose rifles often have uncommon twist rates. For example, if you are building a varmint rifle and want to shoot the short 35 grain, 40 grain, and 50 grain bullets, a 1:12, or even 1:14 twist would be best. On the other hand, long range High Power shooters often select 1:8, 1:7.7, 1:7, or 1:6.5-twist barrels to stabilize the long 77, 80 and even 90 grain bullets used for 1,000 yard competition. Additionally, new testing of heavier rounds (68-77 grains) seems to show that they perform very well in simulated tissue and may be a better defensive choice than 55 grain or 62 grain rounds. The majority of shooters, though, typically shoot bullets of 50 to 69 grains in weight (note that the 62gr SS-109/M855 bullet is as long as a 71 grain lead core bullet) and should select 1:9 twist barrels. At typical .223 velocities, a 1:9 twist will stabilize bullet lengths equivalent to lead-core bullets of 40 to 73 grains in weight.

1:12 twist rifles cannot stabilize SS-109/M855 bullets and 1:7 twist rifles are slightly less accurate with lighter bullets and will often blow apart the thin jackets of lightweight varmint bullets. The 1:7 twist is used by the military to stabilize the super-long L-110/M856 tracer bullet out to 800 yards, but unless your plans include shooting a significant amount of M856, the 1:9 twist rate is better suited for general use.

There is, of course, an exception: if you want to use loads utilizing the heavier, 75-77 grain match bullets currently used by Spec-Ops troops and other selected shooters, you'll want a 1:7 twist barrel. Although military loadings using these bullets are expensive and hard to get, some persistent folks have managed to obtain a supply, and will need the proper barrel twist to use them. Anyone who foresees a need to shoot this ammo should consider a 1:7 twist barrel.



Thanks for the info now if I could sell my damn Sig 220 I can get what I need to finish my build.
Link Posted: 1/9/2005 7:07:32 PM EDT

Originally Posted By Ghost-1:
Okay so a chromoly barrel is not lined, so how good are chromoly barrels and how accurate are they? How hard are they to clean?



Chromelined barrels are chrome moly barrels with chrome lining. Chrome moly barrels are just plain barrels. Chrome moly barrels are pretty accurate. Although with modern chrome lining, you'd be hard pressed to tell the difference in accuracy between a plain barrel and one that is chrome lined.

As far as how hard are thye to clean, they are harder to clean than a chrome lined barrel. I don;t really know how to gauge that. If you have cleaned both, then you'd know the difference.
Link Posted: 1/9/2005 10:27:25 PM EDT

Originally Posted By knightone:

Originally Posted By Ghost-1:
Okay so a chromoly barrel is not lined, so how good are chromoly barrels and how accurate are they? How hard are they to clean?



Chromelined barrels are chrome moly barrels with chrome lining. Chrome moly barrels are just plain barrels. Chrome moly barrels are pretty accurate. Although with modern chrome lining, you'd be hard pressed to tell the difference in accuracy between a plain barrel and one that is chrome lined.

As far as how hard are thye to clean, they are harder to clean than a chrome lined barrel. I don;t really know how to gauge that. If you have cleaned both, then you'd know the difference.



Okay thanks I think I will stick with a chromed lined barrel.
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