FN machine gun steel AR barrel

[nathan]

Anyone have them ? HOw s the accuracy ? Thicker chroming means better durability but accuracy could be so so...

http://www.aimsurplus.com/product.a...th+5.56/.223+Upper+Receiver+Group&groupid=750

 

[Jason248]

I have an 18" FN CHF barrel and it's very accurate, I can manage 1" groups wit it at 100 so I'm happy with it

 

[M1key]

20 inch GI profile barrel is very accurate.

M

 

[MagnumWill]

+1. I have two of them, an 18" and a 20"

 

[LAGS]

Chrone Linned surplus Machine Gun barrels make Very accurate and durable barrels.
I know guys that are using M-60 barrels on their bolt action rifles, with and without the flash hider.
I would love to find a Russian, SG-43 chrome lined barrel in 7.62x54 for a long range rifle that I want to build.

 

[gotigers]

I have one in 10.5". Runs perfect and more accurate than I thought a 10.5" would be.

 

[MistWolf]

FN barrels are of good quality and will stay within 2 MOA wth good ammo. If all you're gong to run is blaster quality ammo any accuracy loss due to chrome lining won't be noticeable

 

[C-grunt]

Noveske uses those types of barrels and their chrome lined barrels have been known to be MOA regularly.

 

[Nugilum]

Crap! I'd jump on this if I had the finances!

 

[Jackal]

Well, my PSA FN CHF .625 pencil barrel is more accurate than my BCM .625 pencil with all but heavy match type loads. Both are 16" middy 1/7's. Kind of annoying really, considering the cost difference between the PSA and the BCM.....:banghead: It somewhat bothers me when the "cheaper" rifle is more accurate.

 

[HOOfan_1]

Rumor has it that BCM barrels are also made by FN

 

[aubie515]

What is everyone's definition of "very accurate?" I personally wouldn't consider MOA "very accurate", but that's just me.

FN is a DOD contractor, so rest assured that you are getting a quality barrel.

 

[Jackal]

Well, my definition of "very accurate" depends on the platform. A .22lr, 1/2" groups at 50m is plenty accurate. A heavy varmint rig, 1/2moa. An AR in the 6-8lb range, 1-2moa depending on components. An AK, 2-3moa. For instance, 1moa from a pencil barreled AR is great accuracy in my book.

 

[119er]

I have the Spikes "optimum profile", which I like BTW, 16" CHF M249 plated, mid length. I believe it is made by FN as well. With 69gr loads (1:7) it is MOA all day from a bench which is awesome for me. I can't hold that accuracy unsupported at all, so I consider that great. It opens a little with 55's so I shoot those in the 1:9 guns.

While you didn't mention your accuracy goals, I don't think you will be disappointed if your goals are anything short of winning matches. And it is doubtful that is you goal judging by the upper shown. That one looks like a pretty heavy barrel too.

 

[Tirod]

The "machine gun steel" isn't so much, it's the cold hammer forging requirement that has to be met. Once done, all barrels are about the same, and dead soft annealed to prevent them losing temper. Nobody much heat treats a barrel for strength if it can be mag dumped to over 700 degrees - it will lose temper and if that strength was necessary, it could fail.

Therefore, barrel steel is mostly selected for it's machining or fabrication qualities. Like "surgical steel" knife blades, it's mostly marketing hype. With over a dozen stainless grades in knives, there is a significant difference in performance. With a barrel, it's all about rifling, harmonics, and if chromed, how much deviation in parallel is created.

In the steel alloy ranges, gun barrel steels make lousy knives. And, vice versa. You get nothing extra in a gun out of a high alloy knife steel for all the extra expense and work.

The cold hammer forged is more important. It results in smoother rifling and less deviation from parallel. That is why they are more accurate, not the steel.

 

[tiamat]

a bit off topic, but does anyone else find it odd that Aimsurplus is selling (re-selling?) a PSA upper?

 

[browningguy]

The cold hammer forged is more important. It results in smoother rifling and less deviation from parallel. That is why they are more accurate, not the steel.

Now see that is something I would disagree with. Hammer forged barrels are cheaper to make to a reasonable quality than a cut (and maybe even button) rifled barrel. But you almost never see a hammer forged barrel winning accuracy competitions so I believe a lot of people (competitors) would agree they are certainly not more accurate. I see lot's of competitors arguing about whether cut or button rifled is more accurate (and even which method of cut rifling), but hammer forged isn't even in the discussion.

I have managed to convince myself that there is something to cryo treating. So in my tiny little mind I believe a good quality traditionally rifled stainless barrel that has been cryo treated is the ultimate for a combination of accuracy and ability to take heat input without moving around.

But back to the original question, I am sure those are perfectly good barrels for building into an AR. Unless you are shooting a high quality load (not Wolf/Remington/WWB/etc) in bullseye type competition you probably won't ever notice the difference in accuracy.

 

[HOOfan_1]

BCM and DD charge more for their CHF barrels than their cut rifle though.

 

[Tirod]

The European makers have been hammer forging since the early '70's, you can make the barrel conform to certain configurations that enhance accuracy and reduce the striations that cut or button rifling create.

No argument some cut and buttoned barrels are accurate - those over $400 seem to offer better accuracy. CHF barrels aren't necessarily less accurate than the cheap button rifled ones that still conform to the 2MOA GI spec. The Euro guns were reputedly 1 MOA thirty years ago.

Chrome plating the barrel actually adds inaccuracy because too often it can't hold to a consistent standard of thickness. When air gauged, it's typical to see variations in bore diameter down the barrel, and if it gets too narrow too soon, it can contribute to high pressures which can cause cycling issues and rarely kabooms.

An alternate method of barrel treatment is nitriding, which interacts with the molecular structure to create a hardened layer in the surface of the rifling. It doesn't change the barrel dimensionally, therefore offers a more accurate finished surface.

So, it's less about cut or button rifling and a lot more about what treatment is used to treat the bore. And the Europeans have been nitriding a lot longer than we have - in fact, it's been to Colt's benefit to keep from investing in hammer forging or nitriding. They negotiate the TDP and manage it, therefore have a ulterior motives in keeping things the way they were - in 1959. If anything, the button rifled chrome bore is about the last one being issued.

Not wrong that some precision barrels can be accurate, but the process in and of itself doesn't guarantee it. Precisely why there can be a huge disparity in the price.

 

[MistWolf]

Colt doesn't use CHF barrels for military contract M4s because they see no difference in performance between their button forged barrels made in the US and their CHF barrels made in Canada.

Cold Hammer Forging is about mass producing barrels cheaply and many experts have held through the years that they wouldn't be accurate because of the internal stresses from forging process. So strong was this belief sales of rifles with CHF barrels plummeted in the US. Because of this the American companies quit offering hammer forged barrels for awhile. Or did they?

For years the Remington 700 had a reputation for very good accuracy yet there was a dirty little secret- Some of theyr most accuarate ryfles had hammer forged barrels.

Steyr built many sniper rifles that were well regarded for their accuracy and consistency that were made with CHF barrels. Some barrels didn't even have the distinctive hammer forging marks machined off.

While it's true few CHF barrels are used in match competitions we're talking about an environment where the winners and the also rans are separated by less than a quarter MOA- a difference too small for the average shooter to take advantage of. Chrome lining is a far greater detriment to accuracy than the CHF process.

The reputaton CHF barrels have for being inaccurate is false and patently unfounded

 

[browningguy]

The reputaton CHF barrels have for being inaccurate is false and patently unfounded

I haven't seen where anyone said that. However I see nothing to show that the assertion they are a cheap way to make acceptable barrels is false. And using a $3-5000 Steyr SSG as an example of a CHF barrel is like using a Carrera GT3 as an example for a generic car.

But I agree that only people interested in shooting small groups will see much of a difference, and I also agree a chrome lined barrel on a precision rifle is worse for accuracy than the method of manufacture. To be honest, for the majority of shooters who are only interested in finding the cheapest price for bulk milspec ammo to blast away with, they wouldn't see a difference no matter what the barrel.

 

[MistWolf]

Back in the day when gun magazines were worth reading there were several well researched articles written about the various ways to make barrels. The Germans developed hammer forging to quickly and economically produce barrels during World War 2. Of course you have to produce a large number of barrels to amortize the cost of the machinery. A popular notion arose that hammer forged barrels would shoot inconsistently as they heated up due to internal stresses so much so that it hurt sales. As a result Remington did remain quiet about continuing to using CHF barrels for their Model 700.

However actual performance of CHF barrels has shown that CHF barrels are just as accurate as barrels mass produced by other methods.

using a $3-5000 Steyr SSG as an example of a CHF barrel is like using a Carrera GT3 as an example for a generic car

The barrel only a part of the rifle. A better comparison would be the tires of the cars. Which set of tires is better made? Which suspension would get the best performance out of each set of tires?