Hi Folks,

A forum member asked me if I would give some insight into how our M4's handle on the range because I've started threads on the AK's, pistols and .50 Barretts.

Here's a little background on what we do. We operate a high-volume range in Las Vegas. You can't bring your personal weapons in and rent lanes for an hour. Customers use only our weapons and our ammo. We only use factory new ammo and zero reloads. We keep maintenance log on EACH and every weapon to include cleanings, parts replaced and any other issues that need to be noted. We shoot approximately 400,000 rounds down range each month and the numbers have actually gone up a bit for May and June. Tourists get to shoot everything from Type 99 Arisaka's, M1 Garand C and D's, MP-44's, G43's, M2HB's, 240's, 249's, MG42's, MG34's, M-14's, Luger's, Swedish K's, M203's, M79's and you get the point. Some weapons are very rare historical weapons that rarely come out of collections or museums and see the light of day.

Here are some "facts" about OUR experience with M4's on the range.

- Some of our M4's have well over 200,000 rounds down range. Barrels have been replaced, gas tubes have been replaced, BCG's have been replaced but what sets it apart from the AK47's is that upper and lower receivers continue to function. AK's get to about the 100,000+ round count and rails on the receiver will start to crack. It's an easy fix with tig welding but they crack. We have yet to lose an upper or lower receiver from cracking.

- We get about 20,000 rounds out of bolts before we start experiencing issues. The headspace gauge will start getting closing on NO-GO but not close on field. We will lose a lug on the bolt. The bolt will start skipping over rounds in the magazine and fail to insert a round. We use LMT and Daniel Defense bolts and some will actually go longer but at about 20,000 rounds is when we will start to see issues appear.

- Gas tubes will erode away at the FSB after 12+ months

- Charging handles will "stretch" allowing the locking lever and spring to fly out

- Hammer pins and disconnectors on the 8.5" full-auto's will break after approximately 4,000-5,000 rounds regardless of the buffer weight

- We have yet to lose a single flash hider as compared to muzzle brakes on an AK-47. The muzzle brakes will literally split in half, looking a like bird with his beak open and go flying down range.

- We no longer use ANY piston conversions or factory pistons guns with the exception of the HK-416 "knock-off" TDI upper. I purchased a FACTORY brand-new MR556 and it started keyholing after only 10,000 rounds. I was SO pissed because I spent all that money on the gun and it couldn't last 10,000 rounds. I had barrels from before we even opened the range with 1,000's of rounds on them from J&T Distributing (chrome-lined) that didn't keyhole well into the 80,000-100,000 range. I don't know who makes or made the J&T barrels but I was so pissed that actually wasted the money on a MR556 and that's all I got from it. I purchased two of the 14.5" TDI knock-offs approximately 6-8 weeks ago and they have been on the line daily with ZERO issues. I only purchased them because people will come in specifically request the "416" and even they've never handled a weapon their entire lives, they KNOW that the top half isn't the "416 like in COD/MW".

- USGI mags have outlasted all of the other brands. We use UGSI (Brownell's with tan follower) and on a mag for mag basis, they have outlasted Pmags and a few of the other mags that we get from mfg'ers with new weapons. We don't have to worry about various generations with different weapons like the MR556, SCAR, F2000, Tavor or a couple of others that use AR15/M4 magazines.

- Cleaning bolts and carriers is such a pain in the ass as compared to our AK's, G36's, SCAR's, ACR's and most other platforms. We throw them in the ultrasonic cleaner filled with Simple Green (EPA, OSHA and disposal concerns for us) and they never full remove the carbon from the bolts. The armorers spend so much time cleaning them and keeping all the parts together as compared to most other platforms.

- The only piston system to last on the range so far is the HK416 and TD415 system. Ever other systems we have tried has failed in one way or another. I won't say who's broke or how they broke so PLEASE don't ask. Each mfg has their own system for cleaning intervals and we may not follow their way. We have a way of cleaning and keeping records that suits our needs because of so much use.

- There is company that has an AR system that has some "parts don't need lubrication" and that failed before the end of the first day. I don't think some mfg's understand that people REALLY use their weapons and when you're rocking full-auto all day they NEED lubrication. My armorers and RSO's were laughing when it seized it up because we knew there was NO way it would last on our range.

- The parts that we see break more often are the bolt cam, bolt lugs shearing off, firing pins and gas keys shearing off the bolt carrier.

These are just a few of the things that I can think of on the top of my head. Please feel free to ask questions and I will try to respond sooner than later depending on my schedule.

V/R
Ron

ps: I am sure there are some grammatical errors as I tend to read the words into a sentence that are not there. Some sort of dyslexia-type of issue that plagued me through eight years of college.

Ron,

If/when you get a system in place for tracking accurate round counts, it would be very interesting to see accuracy comparisons (at 100 yards) of the same rifle over the course of its barrel life.

Awesome thread! I'm kicking myself for not stopping in last month when I was there. Next time for sure!

Do you have durability information on your FAL/L1A1 type rifles?

Thanks for starting this thread

AKASL

Please also post experiences with other sub guns, MPX, Scorpion, Kriss Vector in the Pistol Caliber section:  http://www.ar15.com/forums/f_6/48_.html

I promise to get around to getting info on these weapons plus the FAL (I think may have given some information in the FN thread?) soon. With one of these weapons I will have to be very tactful in how I post because I don't think that platform has seen this much use. I will give more details and take my time to make sure I don't cross any lines describing our particular experiences with one particular caliber.

V/R
Ron

Has it been mentioned how the titan defense rifle is holding up? Receiver, bolt, etc?

Are they seeing similar life spans as basic AR?

How do the .308 battle rifles hold up?  G3 clones vs. M14 clones vs. FAL clones?

How many shots per flint are you getting out of your Charleville and Brown Bess muskets?

 Oh, man... It's funny cause it's a good question.

Hello there!

Ive been reading through the pages and have noticed that you have been using the CHF uppers from Palmetto. I recently bought one of the 14.7 inch ones with the pinned and welded muzzle brakes. Have you noticed any issues from this? I know you guys have the shorty AR's so you have no need to use one. Just wondering if you have.

Thanks

Epic thread here! Thanks for all the info Doc!

I remember when I first moved to town in 2004. Doc was one of the first gun guys I met at our annual desert shoots.  He let me blast a full auto M4 and Uzi.  and I ve gotten the bug ever since that day I got the shit eatin grin

Your BFV place is so crazy busy...I came in to say hi about 3 years ago. Waited 40 mins and still wasnt able to talk to you. lol. Glad to see you are doing extremely well.

One question. When you talk about all the rounds you are putting through these guns, is most of that full auto?  Seems like that would be a factor when you say a barrel or part lasted X thousand rounds. That full-auto heat buildup does all kinds of things to the metallurgy.

Being a machinist while in the Army, I had to fix plenty of stuff on both wheeled and tracked vehicles because Pvt. Snuffy wrenched on them. Job security

Great thread!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The time I was there, albeit only once, every weapon was firing full auto except the "sniper" rifles.  I think I was the only one who actually wanted to feel what semi auto was like on a M1A1, Bren 805 and STG44.  But then I went burst.

They bill this as "machine gun" tourism.  Pretty sure the weapons mainly see full auto fire.

Anymore updates on how nitride barrels are performing, or how PSA's stuff is still holding up?

Nitride barrels, in OUR experience, don't last as long as the chrome-line barrel. I don't want to get deep into but that is OUR experience.

V/R
Ron

Ron, that's the very FIRST data point on this subject that has any credence.  Thanks!

Now that's some valuable data there!  There's lots of hype about nitride barrels, and I have yet to see any actual credible data on it beyond a few biased individual reports. I *Think* nitride is supposed to be pretty good, but don't have any data like this to say.  

I'd love to see more of your data.  My expectation is that the CL chrome-lined barrels last longest, the chrome-moly barrels last less long - and the nitride barrels last somewhere about half way in between.  You are one of the very few people who actually has the data, without a stake in the game, to tell us what it actually is - and it would be HUGE if you could share that!

So please: get deeper into it!  (if you could be so kind; because you don't actually owe us a damned thing!)

Chrome lined will most definitely shine if the bbl's are mostly shot FA conditions. From my understanding, nitride/QPQ bbls only seem to lack in the extreme FA heat. Is FA mostly what is shot through these bbls? Are both types of bbls 4150?

Good info and my suspicion for a while now.  But nothing more than that.  I don't want to drop the money to wear them out side by side to find out.

I will take your word and appreciate the report.

Seriously?  Please make a thread and post results.  What differences are you seeing, and what size groups you seeing them with.  There are some pretty freaking accurate Chrome lined barrels these days.  This something you read about or are you actually seeing these result you can video and post for us?

What barrels, what ammo?

**after rereading this post, please read it with a genuinely inquisitive tone, and not a jackass smart aleck tone.  

Curious about 308's also.

I realize we are talking ARs here . But I own a chrome lined FN spr a1 and it is a solid MOA rifle.  It made a believer out of me.  Done right , it is the cats  meow with  extended barrel life. Chrome is still better all around imo .

That's a valid point.  

There's the full-auto (or near full-auto rate) usage.  And then there's the civilian rapid fire and normal semi-auto fire rate usage.

For example, I know of some test cases where National Match stainless steel barrels that are malonited (nitride) treated, and used in competition.  No service rifle match competitor would dream of trying to do that with chrome lining.  It's supposed to make the match quality barrel last longer,while keeping match precision.  But it's still somewhat experimental - with some people saying it is helping the match barrel (which is a 3000 round life BBL) last longer, and some saying maybe not.

For a rental agency firing full auto, does CL last longer than nitride?  (general opinion seems to lean to yes- and perhaps this thread data confirms?)

For a civilian firing semi-auto rate of fire, does CL last longer than nitride?  (General opinion varies, and this thread has the ability to confirm or dismiss; if the data includes semi-auto barrels as well as full auto barrels - eagerly standing by!!)

How have you found reliability / cycling to be with the 18" faxon barrel that has a .93 gas port?

To expand upon this, the rifling (depending on manufacturer) is the same before either treatment. The difference is that chrome lining is a thicker coating and will ruin/cover/soften your precise machining more than the nitrite finish.

My personal experience is free floating has no to negligible effect at 100yds.  

As for your example.  It is a valid example of one case.  And no doubt clear results.  I would also suggest to you that all of my chrome lined barrels have slightly different favorites.  I have a Chrome lined FN that shoots right about 1MOA with Federal Gold medal match.  Does my one example make it better than your Faxon.

I do not discount your results, I just suggest the accuracy gains that are supposed to be real and documented are not that astonishing.  If you had moved down into a .5MOA range or something close to that, I would acknowledge a clean win.  As of now I will acknowledge valid results because you posted them.  

Faxon makes good barrels too.  The differences I have seen are just not that big, if any overall.

It is a nitride finish, and tell that to FN(ruin/soften).  They seem to be pretty freakin good at it in my experience.  

Not saying this poster is doing it, but I find it funny that with one post we have gone from (with some people) nitride is a harder superior finish....to now they are just more accurate.
 I have several FN CL barrels, the ones with evil extra thick chrome, and I am just not seeing the huge difference in accuracy vs the nitride barrels I own or have access too.

That said, I have never stated nitride is bad.  Just that it isn't chrome lining.  I prefer quality chrome lined barrels.  In most cases that means I pay a little more than I would for a VERY QUALITY FAXON nitride barrel.  I also have a nitrided barrel that costs almost as much as my FN's, and I do not notice the accuracy difference.  

Bottom line more than one way to skin a cat, but until it is studied in mass, I will never believe a nitride barrel lasts longer than a chrome lined barrel.  

No, not so much a challenge as just a different perception or your observations.  Posting print is dry.  A good discussion, but certainly not meant to dismiss you.  I just see it differently to some degree.  

I have no problem with nitride being fine by you.  I won't argue at all it is a bad strategy.  Different strokes.

I am very familiar with the nitride process.  I drank the heavy kool aid for a while.  I still think it is a fine treatment process.  My point, not aimed at you so much, is so many people claim nitride is SUPERIOR to chrome.  It just is not.

You can pick a quality or two where it clearly bests chrome, like overall corrosion resistance.  But I am just saying there are some really fine and accurate chrome lined barrels out there.  Some you pay a higher price for, some not so much.  Green Mountain makes a fine chrome lined barrel, they are accurate, they are cheaper than FN barrels.  Will it outlast an FN extra thick chrome lined barrel, I don't know but I doubt it.  Will it outlast a nitride barrel, I don't know but probably.  

Who really knows for sure on that last stuff, but good discussion.

**also you mentioned cut stainless because it is corrosion resistant, it is also a good bit softer and potentially easier to cut precise.  Technology is getting better all the time.  The "blurring" of chrome lined rifling is made more of than it is really.  Of course no Chrome lined barrel(that I know of) could best a Krieger type barrel, but that doesn't mean in the scheme of things(the accuracy you have thrown up there) that it isn't fairly easily achievable with quality barrels.  

No offense meant to you by any of this discussion, my apologies to you if I did not convey my message properly.  Good discussion but enough FROM ME derailing this thread momentarily.

Fun discussion.  Here's my 2 cents:

From what I've seen elsewhere and here, Nitride appears to be more accurate than chrome. However, it isn't huge.  It is a tradeoff.  Nitride is less expensive, too.  On my SHTF rifles, though, I'm sticking with Chrome.  I've never seen any evidence that Nitride lasts as long.  I also don't know about corrosion protection with Nitride. Chrome is proven in the harshest environments.  

Truly, though, I don't think there are great odds of me being in a situation where the benefits of chrome lining will come into play for me.  It makes me feel better and is like an insurance policy.

You could have just as easily compared your nitride barrel to a good performing colt socom. I own one, it is legit sub-moa with my 50 grain VMAX reloads. I also have a 14.5 voodoo nitride barrel that is nowhere close the the socom. I'm just pointing that out because comparing two different barrels from different manufacturers doesn't mean at all that nitrided barrels in general offer a 35-45% increase in accuracy over an equal chrome lined barrel.
I don't own any full autos either, and over the last few years I've had a few beater guns, and I used to shoot A SHIT TON. I've posted about it here in the past but I had a nitride barrel start tumbling at a relatively low round count(well under 10k, probably more like 6-7k), I had a BCM with probably close to double that round count and still shot like new. Both shot a mix of my cheap bulk reloads and steel on lazy weekends. The only reason I own the nitride voodoo I have now is to shoot the piss out of it along with my current BCM to see if I get the same results. We'll see, but in my experience- the minute theoretical accuracy gain doesn't make up for the real(in my limited experience) decrease in barrel life vs a good quality CL barrel. This time I'll record the round counts etc as they increase since I'm actually trying to learn something unlike last time.

Interesting conversation, but this is not the place for it.

This is one of the most useful threads on the site, so please don't ruin it, start another thread and leave this one to Henderson.

Sorry if this has been covered, I haven't hit every single page yet. I'm wondering if there is any durability difference noted on bolts made from different steel. 8620 vs 9310? Lot of companies have gone to 9310, but in the bullet hoses you guys run is it really better?

Or nitrided vs phosphate bolts. I'm interested in this as well, but I thought I read on here they pretty much stick with normal 158 bolts, I could be wrong on that though. 

The military uses chrome lined barrels in their machine guns. They've tested both. They use nitrided barrels in a few other guns. That's a data point for you. Daniel Defense stopped nitriding altogether because they were experiencing barrel chipping from full auto fire. Chrome is superior, at this point, to nitriding for longevity in FA. Is it more durable in semi-auto? That's a great question. Sons of Liberty told me they were getting 20k+ on their nitrided barrels in FA. So take that for what you will. I'd be curious to know how well LW50 barrels hold up? They can be purchased bare and nitrided. I'd also love to see Cryptic Coatings used in a bore. Much much harder, slicker, and heat resistant than either chrome or nitriding.

Edit: LW50 barrels now have a "LifeHD" treatment which they claim is slicker than nitriding with double the corrosion resistance.

sorry, I somehow mixed milspec carrier steel vs bolt...but the question remains!

Ron, I've been following this thread off and on for two years now. Thanks for all the good, real-life info.

It looks like there's no good reason, from your info and uses, to stray far from Colts and the upper tier PSA (with colored Magpul furniture, of course).

Thanks, again.

Ron, are your nitride barrels all in full-auto guns?  Are any in semi-auto guns as well?  I ask because I'm curious if semi-auto fire helps the nitride barrels keep pace with the CL barrels a little better.

Well, you have finally rediscovered something that the Army found out almost exactly 60 years ago....

An Army report titled: "A Test of Erosion and Performance Characteristics of Nitrided and Chromium-Plated Barrels for the Caliber .30, M1919A4", has this to say:

Being slippery make no difference, as mechanical rubbing wear is not the predominant erosion mechanism. In fact, it is a very, very minor one.

The major cause of barrel erosion is heat.  The Flame temperature of burning propellant is higher than the melting point of steel, while the heat is applied for only a fraction of a millisecond, the damage done accumulated.  The chromium plating acts and a thermal barrier between the hot flame and the steel, offering some protection.

Meanwhile a bunch of other people won't say that - they'll tell you either that it's not superior, or that they honestly don't know, but that a given level of accuracy can be achieved at a lower price point with the nitrided barrels.

Yes I'm able to gather as much...but friction is big as well, also creating more heat. I'm still trying to get someone to buy that barrel and tell me about it. It's also using a different steel. You should buy one!

The dead horse of chrome vs nitride has been beaten so much that it is now a fine puree.

Chrome is harder and resist heat better, we should know this by now. Nitride is not quite as hard, and doesn't stand up to heat as well.

Internet OPERATORS must have chrome for their twice a year 50 yard range outing.

Nitride is perfectly fine for civilian semi-auto use, and quality, accurate barrels can be had for half the price of chrome. It is also easier to make accurate barrels with nitride, as the cut can be more precise, not having to take into account the thickness of the lining - read "you can get a more accurate barrel cheaper"

This has been summed very nicely roughly a billion times: Full auto, mag dumps? Go chrome. Semi-auto? Why spend more on chrome?

I agree with everything you are saying, but are "mag dumps" even a problem? I don't mean drum mags, just regular old 30 rounders. Is that creating enough heat in semi auto to wear a nitride bbl significantly faster than normal use or would it pretty much take a belt fed or repeated mag dumps one right after the other?

As others have said, let's leave this thread to Hendersondefense very kindly sharing his real-world experience. Hash out other issues in a thread that pertains to them or start a new thread for it. The off-topic posts make it hard to find the valuable, technical information that people who regularly check this thread are looking for.

Hendersondefense shared his own experience with chrome-lined and nitrided barrels. Your personal opinions about the merits of one versus the other or what one or the other does or doesn't do detract from the topic of this thread. Moreover, it's all been extensively discussed already elsewhere.

Sooo I'm not going though this whole thread looking for it, is there any data on the Tavor or AUG? Just curious how a quality 5.56 D.I. 20" AR with proper sized (not over sized) gas port stacks up in terms of parts reliability/service life.

Ron
how are you govnah gas blocks holding up?  Since micromoa shut down are you using something new?