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Posted: 1/19/2006 8:41:51 AM EDT
Hello fellow shooters.

This is my first post here, though I have been lurking for some time now, and I am very active on other firearms forums (www.gunforums.com, www.rimfirecentral.com).

I have been planning the purchase of an AR15 style rifle for some time now, to fill out my collection.

Rather than start another "Which is best?" thread, where we all talk about Colt vs. Bushy Vs. RR Vs. DPMS Vs. Olympic, etc....

Here is my question: I am concerned with barrel life. What choices are there in terms of materials, chrome lining, etc... that I can make to help keep my barrel shooting MOA for as long as possible?

Currently, I am looking at a DPMS with the 4140 Chrome-moly barrel and a chrome lining.

If I had unlimited $$ I would get a Novesky N4CQB...but that is out of my league.

Is a Stainless Steel barrel going to outlast the 4140 Chrome-moly (assuming equal use and treatment)?

Do you guys have any recommendations? I do mostly bench/target shooting...so accuracy is important to me. My modded 10/22 shoots 20 rounds inside a dime at 50 yards (match ammo)...so I"m a little spoiled.

Thank you all very much for your time.

Great forum!

Chris.
Link Posted: 1/19/2006 9:44:20 AM EDT
Stainless is for accuracy only...not longevity. You'll want a 4150 or 4150 "vandium" barrel with chrome lining. I think Bushmaster has about the best bang for the buck barrels. I went with Sabre because I wanted a mid-length gas system.
Link Posted: 1/19/2006 9:51:41 AM EDT
Bushmaster uses 4150 steel for their barrels and is a sound choice. <----chromelined

You may have some luck on the EE in finding a good slightly used Colt barrel (same steel, different testing procedures...if that means anything to you). <-----chromelined

Chromelining will effect accuracy to a slight degree due to unavoidable inconsistencies in it's application. Unless you're going to shoot 1,000 yard matches this shouldn't sway your choice.

Stick with the aforementioned barrels for longetivity.
Link Posted: 1/19/2006 10:13:07 AM EDT
Thanks for the quick reply :)

4140 and 4150 are different by only the range of carbon, and the difference is about .1%. This will effect hardness by a max of 1-2 HRC assuming proper hardening and tempering.

So...I'm guessing that the 4140 with a chrome lining is probably comparable with the 4150 with a similar chrome lining.

Just in case anyone wants it, here is some data on both steels:

Designation: 4140
Carbon 0.38–0.43
Manganese 0.75–1.00
Phosphorus, 0.035
Sulfur, E 0.04
Silicon F 0.15–0.35
Nickel ---
Chromium 0.80–1.10
Molybdenum 0.15–0.25

Designation: 4150
Carbon 0.48–0.53
Manganese 0.75–1.00
Phosphorus, 0.035
Sulfur, E 0.04
Silicon F 0.15–0.35
Nickel ---
Chromium 0.80–1.10
Molybdenum 0.15–0.25


Thank you both for the info...I'll try to find either a Colt or Bushy barrel as a possible replacement...and I'll look at Sabre as well.

Best Regards.

Chris.
Link Posted: 1/19/2006 12:01:12 PM EDT
What is your accuracy requirement? At what distance?

A stainless barrel will easily go 10,000 rounds if your accuracy standard is nailing the std .mil silhouette target at 300 meters.

It will not reach past 5000 rounds, in general, when your accuracy standard is 1 MOA at 600 yards.

Link Posted: 1/19/2006 12:09:16 PM EDT
[Last Edit: 1/19/2006 12:10:01 PM EDT by lastsonofgilead]
SWO_daddy.

Most of my shooting is confined to less than 100 yards, due to lack of a proper range anywhere near me. (Illinois sucks).

My accuracy requirement is that I am hoping to keep the rifle shooting MOA at 100yards. So if I can keep groups inside 1" at 100 yards...I'll be happy.

When I started researching the AR15 style rifles I read a few articles (which may have been full of s$%t) that indicated some barrels going from MOA at 100 yards to 6" at 100 after as few as 2000-3000 rounds.

I'm still going to buy the rifle...I'm just trying to get a feel for how often I will need to change barrels.

If I can expect a quality barrel to still nail a standard Mil. target at 300 yards after 10,000 rounds...heck...I couldn't ask for much more than that.

Best Regards.

Chris.
Link Posted: 1/19/2006 1:43:01 PM EDT
There are chrome-lined barrels that will consistently do 1MOA with ammo they like; but I don't think the DPMS barrel is one of those and I don't think you will find any chrome-lined barrels that will do that within your budget if a Novseke is out of reach. On the other hand, there are no shortage of chrome-lined barrels that will do 1.5-2MOA for a very long time (10k minimum) at 100yds (providing the chrome lining doesn't flake off).

An unlined DPMS chrome-moly barrel will start to suffer around 8k and be pretty well dead by 10k if you run it hard.

I don't have much direct experience with stainless barrels and no long term experience; but I am told they do well accuracy wise but are more susceptible to throat erosion from heat. If you baby them. they can provide better accuracy than a chrome-lined barrel over a longer round count.
Link Posted: 1/19/2006 5:30:32 PM EDT
Stainless is for accuracy only...not longevity.

I beg to differ. Stainless is for corrosion resistance. For marine use, an officer's trunk gun, etc, Stainless is excellent. Oly offers quite a few barrel contours other than just bull barrels. There is a reason people buy them, they don't rust.
Link Posted: 1/19/2006 6:40:02 PM EDT

Originally Posted By A_Free_Man:
Stainless is for accuracy only...not longevity.

I beg to differ. Stainless is for corrosion resistance. For marine use, an officer's trunk gun, etc, Stainless is excellent. Oly offers quite a few barrel contours other than just bull barrels. There is a reason people buy them, they don't rust.



Well considering I am spending good money on a new stainless barrel, I would welcome any firsthand experience you have on the subject. Feel free to tell me how many rounds you have through both types of barrels and your resulting accuracy from both.
Link Posted: 1/19/2006 7:34:17 PM EDT
[Last Edit: 1/19/2006 7:52:49 PM EDT by theshootersden]

Originally Posted By A_Free_Man:
Stainless is for accuracy only...not longevity.

I beg to differ. Stainless is for corrosion resistance. For marine use, an officer's trunk gun, etc, Stainless is excellent. Oly offers quite a few barrel contours other than just bull barrels. There is a reason people buy them, they don't rust.



Stainless don't rust? Get out... I thought it could...

Stainless steel is much more corrosion and rust resistant than normal chrome-moly but doesn't compare to chrome lining... They resist fouling and clean up easier than chrome-moly barrels and typically last as long as chrome-moly barrels do... You can expect thousands of rounds with proper maintenance and no abuse...

Chrome-moly barrels have the ability to be highly accurate when broken in properly and are the least expensive of barrel choices... Unlined chrome-moly barrels normally have the shortest life of any material because they experience erosion from bullet friction at a faster rate compared to chrome lined barrels... If used as semi-auto only, this life can still be thousands and thousands of rounds... Plain chrome-moly isnt resistant to corrosion or fouling and is the most difficult to clean... With all of this said, a quality unlined chrome-moly barrel will more than suffice for the average AR15 owner...

Chrome Lined is basically a chrome-moly barrel where the barrel and chamber are internally lined with a thin layer of chrome through an electro-plating process... Chrome lining offers resistance to rust, corrosion, fouling and is easier to clean... Barrel life is also extended when chrome lined...

Lining a chrome-moly barrel with chrome also has the possibility of reducing accuracy... Therefore, a chrome lined barrels is often used more as a work/CQB/SHTF barrel, not as a match/target/competition barrel... Although I have seen some truly excellent accuracy from various chrome lined barrels... MOA can easily be obtained from a quality barrel that is properly chrome line...

Link Posted: 1/19/2006 8:02:58 PM EDT
[Last Edit: 1/19/2006 8:03:27 PM EDT by Variablebinary]
Depends on what you mean by barrel life.

Is it when accuracy degrades or when the barrel explodes.

I've got a chrome moly 4140 that is around 21k and still does minute of torso at 100 yards. There is so no issue so it doesnt get changed
Link Posted: 1/19/2006 8:48:05 PM EDT
SS can rust, but it much more resistant.

I replaced a SS barrel with well over 20k one of my sons had used for carbine classes, and quite a few shoots. I know I had about 8k through it when I gave it to him, he estimated the rest from the appx number of SA battle packs he had purchased and run through it.

The lands were fine, throat looked fine. The barrel was replaced because the extension lugs were beginning to round off.

In my experience a SS barrel will last about as long as a chromemoly barrel.
Link Posted: 1/19/2006 9:18:08 PM EDT
Thanks for the input. For comparison, I've run a 16" Bushmaster HBAR for the past couple of years. Best accuracy was the 1-1.5MOA or slightly sub-MOA group (happened once in a while but not consistently). Until about 6k rounds, I could hit an IDPA silhouette at 500yds about 25rds out of 30. After 7k or so, that number dropped off to around 15 out of 30 at 500yds. It was still a <2MOA barrel at 100yds; but it just didn't have the accuracy it used to have at longer ranges.

I'd also add that you could clean that Bushmaster barrel until hell froze over and you would still get grey gunk out of it. In contrast, the stainless match barrels I have had limited experience with clean up much easier and faster. Still, I have real limited experience with the stainless; but it seems to me like it might have more going for it than is commonly acknowledged here.
Link Posted: 1/19/2006 9:22:30 PM EDT
Funny how when someone asks how long a bbl lasts here...people say 10K but when you have something on EE..anything over 300 rounds is used and abused...
Link Posted: 1/20/2006 5:52:00 PM EDT
Colt_sporter.

Sorry for the possibly dumb question...but what is EE?

This thread has given me quite a bit of confidence in my purchase...thanks a lot. Chris.
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