(another AR topic about) Cold hammer vs. Button barrels

[RP88]

hi, sorry if I'm beating a dead horse but I'm still in the course of deciding between the two.

Here is what I know (or think I know), based of factual, word-of-mouth, and/or anecdotal claims.

Button rifling:
-more expensive to make barrels, but since the machining is everywhere, many smaller-scale manufacturers that don't have the tens of millions sitting around go this route.
-are generally more inherently accurate, not withstanding quality of manufacturer or equipment
-do not tolerate heat as well; which can lead to quicker erosion and loss of accuracy overtime and temporarily during excessive use
-interiors are rougher and need more machine work to finish; this can lead to variance
-quality can suffer greatly if a manufacturer uses bad or worn equipment; this can also lead to more variance and non-concentric manufacturing.

CHF:
-manufacturing process is dirt cheap and extremely fast, but the machinery needed is extremely expensive
-less overall machining needed
-metal is more cold-worked and made to a denser or less rougher grain, leading to better tolerance to heat
-inherently not as accurate because the machining process is not as precise in respects to the rifling (though high quality control and standards can overcome this)
-the extra strength and heat tolerance means less erosion, which saves its inborn accuracy much longer

so, it sounds like that CHF would be the way to go if one wants more life out of the barrel.

BUT...all of these excludes the fact that - in a serious AR as well as other guns - the barrels are chrome-lined. From what it seems to me, the chrome-lining dictates more on heat tolerance and durability than the material does. Sure, chrome is extremely thin in barrels. But, it takes tens of thousands of rounds to wear out a chrome-lined barrel. That says a lot on the importance of chrome in a barrel meant to take a lot of abuse, as we already know.

So, once you factor in chrome-lining, what advantage does CHF have then? I was thinking maybe the denser material helps 'reinforce' the lining and hinder erosion since heat and friction is overall more tolerated by the barrel? Or does it simply just last longer once the chrome wears out?

And then, for that matter, how much longer would a CHF barrel last compared to a button-rifled barrel?

 

[kwelz]

I have heard (and seen) the opposite in CHF barrels when it comes to accuracy. They seem to be more accurate than their standard counterparts.

Think of it this way. Some of the most accurate chrome lined barrels out there are Noveske. And they are CHF that are double chromed. That means they should be less accurate. However that is not the case.

 

[RP88]

yeah, but Noveske puts a lot more into those barrels.

I'm more wondering how it adds up when comparing, say, the people making our current standard issue and/or regular market rifles, or just manufacturers making/offering identical barrels.

 

[kwelz]

I hear ya.
I can tell you this. All my current ARs use CHF barrels.
2 Noveske, 1 Daniel Defense and 1 BCM.

I shoot MUCH better with all of them than I did with my old ARs. However it is not an apples to apples comparison because I feel I have become a far better shooter over the past couple years as well.

The only quality guns I have to compare them too are a Colt 6940 and a BCM standard middy.

 

[RP88]

Sounds good.

The $90 doesn't sound like too terrible of an expense but I want to make sure it is for more than a negligible advantage.

I'm not so worried about the extra cost (I'm not gonna take a huge hit because I plan on selling my old upper group to cover most of the trade-up), but I'm also trying to pick up a VLTOR E-Mod or a Magpul ACS or something with some weight to help counter-balance the front-heaviness of the middy platform.

 

[kwelz]

I don't think you will find the Middy any more front heavy than a carbine. I use IMods on all my guns except one. It has an EMod and I am thinking about replacing it even.

 

[Z-Michigan]

Your list is basically accurate, but the differences are not that great.

Chrome lining helps either type of barrel, but it wears out fairly quickly, especially in the throat. I think that's where the hammer forged barrel makes the most difference in durability. The CHF also tends to have a slight edge in hardness.

I consider CHF superior for durability and all-around use, and I have a couple, but I don't think this issue is worth sweating unless you are a very high volume shooter.

 

[RP88]

I'm not a high-volume shooter, but a negligible amount of money for piece of mind and insurance is not too big of a deal. That is why I'm thinking CHF.

I will never shoot enough rounds to replace a barrel ever, most likely. And even if I did, it wouldn't matter; if I can outshoot a barrel then I can afford the $200-$400 to replace a barrel and/or whole upper group. With that in mind, it makes me think that money saved on a button barrel is better.

 

[TonyAngel]

You're over thinking it. Get a good barrel from a good manufacturer and just go shoot. I have hammer forged, button rifled, chrome lined, non chrome lined and they all shoot. You probably won't be able to tell the difference unless you put a higher (than 6X or so) magnification scope on the rifle and then bench and bag it.

Keep in mind also that most of the "match" grade barrels are stainless, are not chrome lined and have cut rifling.

Hey, if you're just trying to put together a solid performer, take a look at the "Select" barrels being offered by Ranier Arms. At under $200, that's a hard deal to beat.

 

[RP88]

I'm going the BCM route. Trying to get a general purpose carbine built up. Regardless of whether or not I run it hard, I'm just wondering if CHF is worth the $90.

 

[Z-Michigan]

For just $90, if that amount isn't a big deal to you, I'd get it. If that amount will keep you from buying an optic, taking a class, etc. I would not do it.

 

[RP88]

I'm only replacing the upper and the stock, so no - the $90 won't affect anything else.

I already have everything else.

Thanks for the help. I think I'll go ahead and get CHF for piece of mind since there doesn't seem to be any drawback to it.

 

[kwelz]

Good choice in my opinion.

I really stopped looking at what I spend on an AR a couple years ago and I have been happier for it.

I may have to wait an extra few weeks or a month, but I get a better product. Now of all my ARs the "Cheapest" gun is a SBR made from a Colt lower, VLTOR VIS upper and a BCM CHF barrel. =)
Not exactly bargain bin parts there.

I think a lot of people could benefit from not getting hung up on cost and instead looking at the benefits for their needs.

 

[TonyAngel]

Are you going with a mid length or carbine length gas system?

 

[Quentin]

The upper I recently bought is a Daniel Defense CHF 16" LW midlength and the price was very good due to an end of the year sale. I'd highly recommend the LW midlength and if you shop around you can get CHF for much less than $90 extra. Of course BCM rarely reduces their hammer forged version but check out smartgunner.com for DD.

 

[RP88]

Are you going with a mid length or carbine length gas system?

Middy.

I currently have a CMMG midlength and I like the feel and natural design to it around the 16" barrel (which I'm also preferable to due to NFA hassle, improved ballistics, wanting to actually change out my flash hider and other parts more easily, etc.). I also see no reason to take a hit on also selling the pricey DD Omega rail set/tube that is worth almost as much as a stripped upper.

BCM was supposed to be my first choice, but I fell into the panic and settled with CMMG. I'd be content if it wasn't for CMMG being exposed for certain shoddiness that really concerns me - as well as the big problem of them possibly lying to me about the quality of the barrel. That was the deciding factor for me buying from them in the first place, so I'm ousting them and going with BCM like I should have patiently waited on and done the first time.

Of course BCM rarely reduces their hammer forged version but check out smartgunner.com for DD.

if there are any middies floating around, I'll consider it. I know that DD is a good buy. If they outweigh BCM then I can consider selling off the rails I have now and trade up/over for appropriate ones if for some reason I do go back to carbine length.

 

[TonyAngel]

For what it's worth, I'm a big fan of Bravo Company products. I do think that you get a lot for your money, but truth be told, some of the best fitting parts that's I've seen with the cleanest machine work and upper receivers with no high spots have come from Daniel Defense.

I used Daniel Defense stripped upper in my last two precision AR build and wound up not having to do anything with them except throw them together. The very last Daniel Defense upper that I got, I got to replace a Vltor upper because the DD's tolerances were all tighter at half the price. What I'm saying is that I wouldn't hesitate to get into a Daniel Defense rig.

The only department that I'd be really swayed toward BCM in is if I was putting together a build for a "field" type of rig with real accuracy in mind. BCM's SS410 barrel based builds are real tack drivers.

 

[kwelz]

Tony, it is hard to go wrong with DD. My personal favorite gun is a DD in fact.

 

[Shadow 7D]

WoW read in to this,
both methods are considered a cheap method that is likely to leave a cold, stressed and very worked barrel

they are used, because the are FAST, and relatively simple, compared to actual cut rifling, which many prefer for accuracy work.

Now that said, a barrel, that has been annealed to relieve the stress, and is properly finished, to make sure that its straight etc. will work work fine, but lets not forget the standard to compare to.

 

[Quentin]

Smartgunner does sell a DD 16" CHF midlength upper without rails, BCG or charging handle for $409 but is out of stock right now. That's a pretty darn good deal, maybe you can get on a waiting list?

http://www.smartgunner.com/DD-16-LW-M-STR-URG-2.aspx

 

[RP88]

that is a great deal. I'm also liking that they have gov't profiled barreled ones as well for the same price.

I've honestly never had a single problem with AR parts not fitting, honestly. Either way, their fit is something to keep in mind.

I'll e-mail them and see if they know how long the backorder is. I'm concerned of getting left in the dust again if BCM sells out again, but we'll see. Perhaps patience will give me time to get a good selling price on my old upper figured out.

 

[Tirod]

Cold hammerforged barrels are the ONLY method used for pistol barrels in the US. It's also the only method used for Euro spec combat rifles. And Ruger rifles, Remingtons, in fact, it's the big secret nobody knows about - most guns in America are already CHF.

It's the milspec AR barrels that are stuck in the '60's, using a standard left over from Garand production. CHF barrels aren't overworked stressed out cheap crap, and they certainly do get a final annealing. You have to leave barrels about dead soft, if they were heat treated hard with stress risers, one enthusiastic mag dumping session would have left them in splinters and the makers reputation in the trash can.

CHF barrels can be much more accurate, as the mandrel they are compressed onto is burr free, can have the optimum rifling, and isn't micro sheared on the interior surface needing to be lapped or broken it. The outer surface is formed to be coaxial to the mandrel, not bored off center and then cut again to true it up. You get a nearly finished dimensioned barrel that barely needs any more work, compared to something still in the middle of numerous setups and processes. It's much less likely to have an inclusion that moves the POI as it warms up. Inclusions are fragmented and reduced, it's the most important feature of forging - molecular alignment.

For the milspec AR, the chromed bore is oversized and plated back to dimension, and that leads to variations in thickness that cause constrictions and inaccuracy. That's why a button rifled stainless barrel is considered more accurate, as it's broached to final dimension, and it can be checked by air gauge and even corrected. Chrome, you get what you get.

Once the CHF process is done, you can nitride the barrel, which converts the outer layer of molecules and adds hardness and high lubricity - without changing the dimensions. Nitriding has to be ground off - it never flakes or decomposes.

Don't let a minimum gov't standard dictate your accuracy or longevity, and certainly don't think CHF barrels are an exotic luxury. If anything, AR's are about the last to get them, they've been standard on foreign and civilian guns for years.

 

[Quentin]

that is a great deal. I'm also liking that they have gov't profiled barreled ones as well for the same price.

I've honestly never had a single problem with AR parts not fitting, honestly. Either way, their fit is something to keep in mind.

I'll e-mail them and see if they know how long the backorder is. I'm concerned of getting left in the dust again if BCM sells out again, but we'll see. Perhaps patience will give me time to get a good selling price on my old upper figured out.

That is a great deal from Smartgunner and they work closely with Daniel Defense so when more uppers are ready they'll get a heads up. Looks like SG has changed their system and now only accept orders when they have stock. Great deal since you pretty much get CHF for free.

When I bought mine before Christmas SG took every order whether the unit was in stock or not. With the fantastic price they and DD were swamped with orders and the average wait was about 2 months, including mine. But I'm glad they did the sale because I got a top notch upper for an amazing price. And I'm glad they took orders even when backlogged or I may not have gotten on the list.

You may come across negative feedback for Smartgunner but it's from people who were mad it took so long. But SG is honest and when that long package came from Daniel Defense and I inspected my fine new upper it was well worth the wait.

Anyway, I hope you soon find the upper you want in stock from BCM or SG/DD. I had a tough time deciding on LW vs. govt profile but am 100% sure I went the right way with LW. Shaves off about 4 ounces and I'm just not convinced that that extra thickness and weight out front does much good except maybe give you a larger selection of gas blocks. Earlier you said you were concerned about a middy being front heavy so I recommend looking hard at the LW profile.


ETA:
As far as fit, the Daniel Defense upper fit very well on my S&W lower. In fact I'll drop in a picture of my Dan Wesson:

(The rifle as pictured without a magazine weighs about 6.5lbs and balances at the front of the magwell.)

 

[RP88]

I'll see if I can try a lightweight profile out. If not, then I'll stick with what I'm used to.

Is there any noticeable difference on how the barrels tolerates and/or dissipates heat?

Also, how do you like the CTR stock? I'm debating between that and a VLTOR E-mod stock right now as well.

It's the milspec AR barrels that are stuck in the '60's, using a standard left over from Garand production. CHF barrels aren't overworked stressed out cheap crap, and they certainly do get a final annealing. You have to leave barrels about dead soft, if they were heat treated hard with stress risers, one enthusiastic mag dumping session would have left them in splinters and the makers reputation in the trash can.

this makes the most sense. I guess with the cold war kicking up though we didn't feel like switching over and re-training workers on new machinery, so it would make sense for military guns to be the last in the US to pick up CHF.

 

[RP88]

bumping.

Also, update: went with BCM. Didn't feel like rolling the dice on how long it would take for people to get stuff back in stock so I paid the extra $80 to ensure I got it. Just for irony, watch the DD uppers come back in stock everywhere tomorrow...