Centurion Arms barrels

[AR-10]

Are these any good?

They are offering an almost complete VIS upper (no BCG or CH) with a hammer forged 14.5" lightweight middy barrel for $875.

I was looking at the exact same barrel from Daniel Defense, but if I were to pay retail for a DD barrel and the same VIS upper I'd be dishing out around $1000.

So, if you include the cost of a low-pro gas block, gas tube, birdcage (which I wouldn't use anyway) plus assembly - this looks like a deal that is too good to be true:

http://www.centurionarms.com/index.php?page=shop.product_details&flypage=flypage_images.tpl&product_id=47&category_id=18&option=com_virtuemart&Itemid=134

Granted you still need some additional components to finish it but I'm not too keen on buying uppers from companies that I don't know anything about, especially if I don't know where the barrel came from.

[Stickman]

Centurion Arms carries very high quality equipment. I own some of it myself, and plan on getting more. I would use and recommend it for duty use without hesitation. I'm not sure I can give higher praise.

[TehLlama]

The bundled uppers with URX or Lite rail aren't too shabby either. I'm quite thrilled with my Mk12/Lite12 upper.

[Aragorn]

I have a 16" Lightweight CHF barrel from them and absolutely love it. Chose it over a Noveske 14.5" Afghan actually, though mostly for the weight. An N4 may would have made the decision more difficult, but I very likely would have still gone with the Centurion. Seems like I read somewhere that their blanks come from FN.

[AR-10]

Very good to hear, I wasn't expecting to read that these guys have so many uppers out there already. Before today I didn't even know about this place.

Can any of you explain what they mean by taper bore?

I noticed that in the barrel specs.

[Uglyduck]

Monty absolutely makes top notch rifles, you can't go wrong with centurion products. Rumor has it Reed Knight of Knights Armament has one of his Mk12's in his safe. He probably has one of everything in his safe but for a guy with enough cash to buy whatever he wants and that company to pick one up says something. His CHF 2x chrome lined barrels are a really tough to beat in accuracy and durability. Tapered bore means the bore becomes narrow from chamber to muzzle. Thats the simple definition and I don't have the expertise to explain the physics it imparts on a projectile other than I understand its intent is to improve accuracy on chrome lined barrels.

[AR-10]

I think I'm gonna order one.

I originally wanted to put a Colt M4 HBAR in a carbine VIS but after playing around with my current build I have realized that I need more handguard space and I'm probably better off selling my HBAR and buying a lightweight middy.

That's why I've been looking at DD's barrels, then I saw these Centurion uppers.

These guys are selling exactly what I need, except for the muzzle device but who cares I'm gonna pin something else to the barrel anyway.

I've even got a spare BCG and CH so I would only need front and rear backups and a red dot.

Thanks for the info, guys.

[Specialized Armament]

Monty absolutely makes top notch rifles, you can't go wrong with centurion products. Rumor has it Reed Knight of Knights Armament has one of his Mk12's in his safe. He probably has one of everything in his safe but for a guy with enough cash to buy whatever he wants and that company to pick one up says something. His CHF 2x chrome lined barrels are a really tough to beat in accuracy and durability. Tapered bore means the bore becomes narrow from chamber to muzzle. Thats the simple definition and I don't have the expertise to explain the physics it imparts on a projectile other than I understand its intent is to improve accuracy on chrome lined barrels.

Seriously? I would love to hear about the science behind this (if there is any)...

[Paulo_Santos]

Not too much help, but this is what I found about the tapered bores:

The idea of tapering a bore to improve accuracy and velocity is not a new concept. The German Army designed its famous 88mm cannon with the tapered bores in order to gain the super-high velocities that made them such infamous tank killers. In the United States, the old Springfield Armory also conducted substantial R&D on taper-bored weapons with positive performance results. In fact, the research published since the 1940's has consistently identified a tapered bore as the ideal bore configuration for both accuracy and power.

[AR-10]

I've never heard of a tapered bore in an AR barrel, which is why I asked.

Just curious, do they start out a little loose at the chamber end while tapering down to a normal bore size at the muzzle end or do the barrels start out normal and get extra tight at the muzzle end?

In a shotgun, a tapered bore makes sense. Here, not so much.

[Quib]

Interesting concept. This is the first I've heard of it.

So as the projectile gets closer to the muzzle I take it pressure increases due to the continually decreasing volume of the bore? This increase in pressure and decrease in diameter of the rifling account for the increase in accuracy?

[Uglyduck]

I'm in the same boat and couldn't find much information regarding the science behind this.

Here's a quote from M4C where Monty explains the rationale behind Centurions tapered bore. It doesn't explain how it works however.



The taper bore is that the bore dimension is slightly smaller at the muzzle end this help accuracy. You may notice that the match shooters will not use standard chrome lined barrels since chrome can not be laid consistently through the bore there will always be variations in the chrome thickness. The taper bore gets tighter as the you get closer to the muzzle this negates any negative affects of chrome lining inconsistencies and ensures that it will not have any negative effects on accuracy.

So the taper bore is to enhance accuracy on chrome lined barrels

...

Source thread (http://www.m4carbine.net/newreply.php?do=newreply&p=550360)

[Quib]

That’s definitely interesting.

I’ve heard of, and learned about tapered aircraft engine cylinder bores, where the intent in a taper towards the top of the cylinder was to keep cylinder pressures consistent at the hottest portion of the cylinder, the head. The taper was designed in to keep the bore diameter consistent at higher temps due to cylinder head expansion.

I wonder if this reasoning has any impact in the design of the tapered rifle bore as well?

[AR-10]

I've been doing some research on this company, many, many shooters are giving the SPR uppers high praise.

I'm actually debating whether or not I should just get a 16" instead and not have to deal with pinning my flash hider.

[Specialized Armament]

Am I understanding this correctly?

Barrels can't be chromed to a consistent thickness and this fact has a negative effect on accuracy. To negate this shortcoming, we made our barrels with tapered bores and doubled the thickness of the chrome which increases accuracy and triples the life of the barrel.

The only science behind the tapered bore is the science of marketing. IMRO...

[Stickman]

I think we are mostly past any issues with chrome lining, there are plenty of chrome lined barrels that are highly accurate.

[Grinch]

Am I understanding this correctly?

Barrels can't be chromed to a consistent thickness and this fact has a negative effect on accuracy. To negate this shortcoming, we made our barrels with tapered bores and doubled the thickness of the chrome which increases accuracy and triples the life of the barrel.

The only science behind the tapered bore is the science of marketing. IMRO...

I was given a link so I figured I’d come over and respond.
Looks like you guys pretty much have the concept. The bore gets slightly smaller as it moves to the muzzle end of the barrel.
I did not come up with the concept and it is not new. So why have you not seen taper bores in the AR platform before?? Probably because using hammer forged barrels is a fairly new thing in the AR rifles. Taper bore is something that is only realistically done by the hammer forging process. The mandrel that is used to put the rifling in the barrel is slightly tapered and this leave the tapered dimension in the barrels as the forging machine beats the blank around the mandrel.
So what does it offer you? Taper bore gives you a slight boost in velocity over a non-taper bore barrel and it help negate any potential accuracy issues caused by chroming the bore since it is not always a consistent thickness.
Taper bore does not extend the life of the barrel our barrels last longer because they are hammer forged and made from a different spec material that was engineered for machine guns. Hammer forging work hardens the material and the chrome is thicker than a normal barrel. The barrel steel is the same used on the MAG58, 240, M249, MK46, and MK48 machine guns it is also the same barrel material and process used on the 1/2moa sniper rifles FN won the FBI contract with and that are still in service. The FN SPR sniper rifles use hammer forged hard chrome lined taper bore barrels to get ½ moa accuracy and this is the same barrel specs and processes I have done to my barrels.
So who else uses this?
Obviously FN, who has the time, money, and resources to do the research to find this type of barrel steel and proof out this type of process and specs. FN hands down manufactures the best machine guns in the world and there isn’t even a close second in this field there isn’t even any two companies you can combine that has as much institutional knowledge as they do in making beltfed machine guns.
HK also taper bores their hammer forged barrels for all their rifles.
So why do I use it?
Well I didn’t really think much about hammer forging and taper bore before I was sent to work doing combat systems development and operational testing for SOCOM. There I worked on several weapons programs one that used these barrels on one of the rifles we were testing. I got to observes millions of dollars worth of R&D and testing that was done and got to see hundreds of thousands of rounds run through these weapons and got to see firsthand that these barrels did indeed last allot longer and on a whole shoot better than standard button rifled barrels that were chrome lined. The difference was significant and I wondered why the hell no one made these barrels for the M4/AR rifles so I figured I would bring them to market myself. I have over 20 years of service and have shot out plenty of M4’s in my time and can with full confidence say this is a improvement I’ve seen it first hand.

Thanks
Monty

[Paulo_Santos]

Thanks for stopping by Monty.

[Specialized Armament]

I appreciate Monty stopping in also. His knowledge will certainly advance the thread and the forum in general.

Technology that sets one company apart from another is typically heralded, worn like a badge of honor by those companies that use it just like Centurion. My suspicion continues simply becuase I was not able to find one instance of the companies mentioned that considered a tapered bore to be of enough value to even mention it on their website, in product guides or press releases.

While I don't doubt that tapered bores exist, I'm not certain that muzzle velocity and accuracy are the reason. I believe that they are a result of a manufacturing requirement specifically for hammer forged barrels. That is to say the manufacturer didn't start out with with intent of a finished barrel with a tapered bore. The tapered bore is a result of a tapered mandrel. Why is the mandrel tapered? For the same reason a rifle cartridge case is tapered. So it can be extracted. An un-tapered mandrel would be extremely difficult to remove from the barrel.

This is certainly theory on my part so I sent an e-mail off to an industry contact to get some additional information on hammer forging and tapered bore barrels.

[Quib]

Thanks for stopping by Monty.

Yes, thank you Sir for taking the time to drop in.

[AR-10]

Monty, thank you for serving and thank you for stopping by to clear this up!

You're about to receive some of my hard-earned money, after reading about your uppers, I doubt I will be disappointed.

[banzaijohn]

Coincidentally there is an article on tapered bores, or squeeze-bore rimfires as the subject of the article, the late Arthur Langsford, called them, in the January 2011 Guns magazine. It says that Langford experimented with barrels of .22 that gradually tapered to .17 caliber, that resulted increased penetration and velocity increases of 25 to 60 fps. It also mentions German designed tapered bore weapons, such as the Gerlich gun which had a flanged projectile that tapered from 42mm to 30mm. The article also states that tapered bores were largely abandoned due to the cost and complexity of manufacture. You can get a free digital download of the magazine here: http://www.gunsmagazine.com/

[Grinch]

The mandrel is about 6in long and the barrels is dragged across the mandrel and beaten around it to form the rifling. Only the last 3in of the mandrels are tapered so only the 3 in of the barrel get the taper bore it is not across the whole bore. the rest of the barrel gets its forming from the first 3in of the mandrel so it is strait. I know it is not required to have the taper to form the rifling since I've spoke with Daniel Defense about their barrels and they said they do not taper bore they use a 6in strait mandrel.

Even if the taper came for other reasons it has the ancillary benefits of a slight increase in velocity and helps with accuracy.

Any of the processes used to rifle a barrel can yield excellent results or poor results it depends on the knowledge and attention to detail the shop takes while making them. I have visited the barrel shop in Herstal Belgium and in Columbia SC and can say I was extremely impressed with their barrels and processes every barrel get bore scoped and inspected at every stage of the manufacturing process. I truly believe they are some of the best barrels in the world and I have seen it prove itself out through all the testing I got to witness.

Thanks
Monty

[TripleBravo]

Good info here. I need to work on my knowledge base concerning barrel making. This has been an interesting read for sure.

[sniperfrog]

I appreciate Monty stopping in also. His knowledge will certainly advance the thread and the forum in general.

Technology that sets one company apart from another is typically heralded, worn like a badge of honor by those companies that use it just like Centurion. My suspicion continues simply becuase I was not able to find one instance of the companies mentioned that considered a tapered bore to be of enough value to even mention it on their website, in product guides or press releases.

While I don't doubt that tapered bores exist, I'm not certain that muzzle velocity and accuracy are the reason. I believe that they are a result of a manufacturing requirement specifically for hammer forged barrels. That is to say the manufacturer didn't start out with with intent of a finished barrel with a tapered bore. The tapered bore is a result of a tapered mandrel. Why is the mandrel tapered? For the same reason a rifle cartridge case is tapered. So it can be extracted. An un-tapered mandrel would be extremely difficult to remove from the barrel.

This is certainly theory on my part so I sent an e-mail off to an industry contact to get some additional information on hammer forging and tapered bore barrels.

Almost all of your custom match grade barrel makers will hand lap a slight taper from chamber to muzzle end. This is well known in the benchrest community to enhance accuracy. Some benchresters even "slug" the barrel to ensure the muzzle is the tightest spot in the barrel.