The more carbine courses I teach, the more malfunctions I see with AR-type platforms. It used to be fairly uncommon, but now it's a regular thing. I'm not talking a once-in-a-while issue with a bad round or old magazine; I'm talking of repeated stoppages or guns that just quit running.

The more "advanced" the course I'm teaching is, the more issues I see. In "beginners" courses I don't tend to see as many issues.

A. From inspecting problematic AR's and talking to their owners, I've noticed a few trends. In general, the guns that I see that have serious issues are either:

1. Owner-assembled. That is, they bought a kit or parts and assembled it themselves.

2. A factory gun that has had numerous parts of the operating system replaced and/or modified.

I am not saying that you can't build an AR yourself and have it run perfectly. I have many students that do that and have no issues at all.......but obviously not everyone is up to the challenge, or some folks bought some inferior parts.

I'll see a student running a good gun, like a recent guy with a Daniel Defense. When it doesn't run, I start to ask him about it and find that he's swapped out parts like the buffer, buffer spring and BCG. When asked why, all he could say was he was talking to some 3-gunners and they recommended it. I asked if the gun was running fine before the "upgrades" and he said it was. Hmmmmm......then why "fix" it.

Caveat: I'm not knocking 3-gunners or any other competitive shooters. I'm a competitive shooters myself and highly recommend it to folks. It has improved numerous skill sets of mine.......but, know what belongs in the training arena and what belongs "on the street".

If you modify a firearm that you intend to use for "serious" work, test it out thoroughly before putting it back into service. If you are looking at performing a modification, have a dang good reason for doing so. Don't fix what ain't broke.

I see less problems in beginners' courses but the students haven't learned to mess with their guns yet! At least, that's my theory.

B. Steel case ammo: I've got no problem with it for training ammo. It's cheap, which means you can afford to practice more. It's not nearly as reliable as "good" brass-case ammo, which I also like in my training ammo as it forces you to practice malfunction clearance drills. That's good stuff as well.

Steel cases don't swell and fill the chamber like brass cases, so fouling tends to blow back around the casing and foul the chamber more. During high round count range sessions, or multi-day training courses, you will need to clean that chamber out or you will eventually have issues. When you break for lunch, run a Boresnake through her a few time. At the end of Day 1, if there will be a Day 2, give the chamber and bolt a quick cleaning.

I would not recommend using steel case ammo as your "serious load" for realsies.

3. Lube well. I don't care what lube you use, I've never seen a malfunction caused by the type of lube used (except 1, see below), but I have seen them caused by little to no lube used.

General rule of thumb: Grease parts that slide/rub and oil parts that rotate. With that said, you can use all grease or all oil and she'll still run.

The only malfunction I've seen caused by lube was a guy that was running graphite. Just don't. The guy using it didn't know better and was told to use it by a Navy Seal/Force Recon/Ranger/Spook who said that grease/oil will attract grit and gun up the action. Well, I'm here to tell you, graphite is very fine grit. Just do not.

Oil and grease can hold grit, but as long as it's held in suspension the gun will run. A wet AR is a happy AR.

I have never in all my 26 years as a gun toter and Instructor seen a firearm malfunction due to "too much" lube. Better too much than too little.

Anyways, thought I'd throw some of this out there. I'he got another AR course coming up that I'm teaching.......we'll see if the trend continues!

Semper Fi!

Thanks for the insight.

Good read.

My most recent armorers class went over this. Based solely on LE and what you should and shouldn't allow on a firearm, and USGI style parts only.

Thank you.
Whats the typical round count and how soon do you start to
see malfs on a poorly set up AR?
Thanks again.

Because I don't use set round counts for drills, round counts will oftentimes vary between 400-650rds per day between individual students.

Malfunctions don't show up at particular round counts. I've had folks whose carbines never ran from the beginning, to folks that got well into Day 2 before they have issues. It will depend on what caused the problem in the first place.

I NEVER dick with a gun that is running...beyond good cleaning and maintenance.
Once you start trying to "Improve" something that is totally reliable, really what is the point?

Wolf used to be my go to training ammo, but it used to be  .10 CPR too.   It worked for me for training,
but gawd it got the gun filthy from blowback.  Which was good for stoppage drills.

Good ammo and an un-dicked with gun usually go well together

All really good points by OP, and I had to learn all that shit the hard way.  
Of course, I was a grunt/11 B

Often see ads for rifles and pistols with swapped out parts.  Owners brag about this, that or the other.  To me, the price goes down as I have no faith in amateur-hour mods. (as reinforced by the OPs observations....)

If you have a weapon for sale and a bunch of mods, you're different - I didn't mean you.  :-)

Excellent observations and advice.  Thanks for sharing.

What were the causes of delayed failures (things that did not show symptoms until day two)?

Good info.



While true, in a "serious" situation with steel you won't be shooting 2K loads before cleaning.  Knowing you gun will let you know what it can run.  I ran 2K of Wolf 62r without issue through my build in a weekend course with one "snaking" between days just so I wouldn't be "that guy" who had gun issues, but I'm pretty sure it could have run all 2K without issue.

My practice rounds are brass, my "serious load" is Wolf 55gr that is stored away.  You won't shoot them in practice because you can't reload them.  My reloads are matched to the Wolf and both 77gr/55gr reloads track with the Wolf 55r on my Acog.  Knowing your gear and actually using it will avoid most of the issues you describe in the "advance" classes.  

The steel case Russian manufactured ammo is not as reliable as the vast majority of the brass case ammo I have used. I'm not talking about the flow back due to the steel cases not expanding, I'm talking about failures due to dud primers and such. Much more prevalent in steel case ammo and the reason I won't use it for "serious" ammo. If you just gotta, then I highly recommend the steel case ammo from Hornady.......it had proven to be a more reliable performer than the others.

Day 2 failures are usually parts coming loose that were not torqued or staked  properly, guns quitting due to fouling when the gun next to them is still running strong. Also, cheap parts breaking, especially in the BCG, e.g., firing pins, bolt lugs, bolt cam pins, etc.

Speaking of carbine classes, you need to stop posting on Arfcom and schedule more classes.

I am guilty, guilty, guilty of being stupid.



Years ago I took a DMR class, and brought my perfectly reliable 20" Sabre Defense Grendel.



I decided right before the class that I wanted to put a lighter stock on it, so I just swapped the lower with a carbine lower that had a CTR or something on it.  (But the AR-15 is modular, and you can put a bunch of different uppers on one lower!!! - Dumb.)



I had all kind of failures throughout the course, and to compound the dumbness, I didn't even figure out what was wrong until I put the upper back on the rifle lower...AND HAD NO MORE FAILURES.



Lesson learned?  When you have a weapon that works perfectly, and you make a change, TEST TEST TEST BEFORE YOU NEED TO USE IT.

Test a gun with three mags fast at 100m if it is good to go then trust it, a real test is seven mags fast as you can hit. Not many target guns can handle that. Grease and CLP/LSA are the secret.

I've got three that pass the 210 fast as you can hit. Love those rifles. Single stage RR trigger and old chrome lined HB.

D_J, got a carbine class scheduled for August and another for November. A couple precision/Sniper courses as well. I'm only allowed to post 1 per month in the GAHTF, but they're all posted in the Tactical Training forum above.

HeavyMetal, I sure do!

Roger that. I'll tag the forum for updates and see what you've got posted. Andy and I are down for the team class in Nov, and I'd like at least one in the next 2-3 months. Something other than "Intro to AR".

I've been asked to do a 2-day carbine course in Camden County in October or November.

Thanks for the post OP.

Regarding your comment to "lube well," I've been doing that for several years now.  The complicating factor is that I always get splash back on my glasses, in my eyes, and/or on my face, every time that I fire.  I assume that I'm leaving it too wet, but where is the optimum level?  Is there a quantitative measurement?

Thanks.

Grease mixed with LSA- no splattah

OP, what failures do you see w/ piston guns, if you see any piston guns in your courses?

waiting for answer.  

Interesting he is not reporting any magazine related failures, but there are so many good mags these days.

I see the same issues with piston guns that I see with DGI guns, for the most part;  if it was well-built and maintained properly, it runs well........if it was not built properly, or improperly maintained, it will fail.

With each course I see less and less magazine-related failures. The vast majority of my students are running PMags, with some Troy and Lancers thrown in the mix. Good mags in a good gun = a good day on the range.

As time goes by, you see less and less beater USGI surplus mags.

OP, your observations mimic my own as well in carbine and DM courses with AR15's.  As I was reading, I started listing things that come up first that I see, before reading those exact problems in the exact order that I see them.

Home-built guns with who dunnit barrels/chambers, mis-aligned or aluminum gas blocks, clipping gas tubes in carrier keys, no lube, LPK issues, strange buffer/recoil spring combos, el cheepo gunshow grade BCG's, Wolf Steel case = malf-o-matic.

The lacquer-cased stuff will shut down a tight-chambered gun as well, whereas the same gun will eat M855 all day long.  The guns will run hot on Wolf, but as soon as you let it cool, then chamber another round, stuck like chuck in many cases, mortaring won't fix even.

Gas blocks
The aluminum gas block is one of the things that will show up on a Day 2 course, especially if it's MLGS.  CLGS + Al gas block will usually erode out on Day 1.  Don't put an Aluminum gas block on your AR15 if you're using CLGS or MLGS, and on a RLGS, it should only be a JP adjustable unit sealed to the journal on more of a race gun or low-volume gun if you go that route.  I personally only use steel gas blocks, with precision alignment with calipers to determine port locations on both the barrel and gas block from a set common datum line, like the shoulder.  I then secure the gas block to the barrel after test-fitting for pneumatic circuit flow.  A lot of you out there are replacing your FSB's with lo-pro blocks, and getting the alignment wrong.

Gas Tube Clipping
Another thing that will shut down a gun that has fired flawlessly for hundreds and thousands of rounds is gas tube clipping of the carrier key.  Once the flange or doughnut wears on one side, it no longer provides the necessary gas seal to deliver gas into the gas expansion chamber around the bolt tail, and the gun will start short-stroking.  When assembling an upper, I pay very close attention to gas tube alignment.  Rifle-length tubes are the hardest to get right.  Inspect your gas tubes regularly, and apply thick lubricant to that area.  The chrome lining of the carrier key (Mil-sepc TDP call-out) will win against the stainless gas tube if it is misaligned.

Reamer Specs
One of the biggest things that is out of your control as the DIY assembler is the specs on the reamer when the chamber was cut.  You may have bought a "5.56 barrel", but if the reamer was run ragged when they cut your chamber, and past the minimum SAAMI reamer spec, you will have a tight chamber.  Tight chambers and gas guns don't like each other at all, and are very ammunition sensitive.

Lube
In addition to the good comments about lube, I will say that I watched Frog Lube shut down several guns this past winter in my Winter DM/Sniper course.  It was as if someone poured microscopic volcanic ash and dust in the receivers.  The guns felt like they were bone dry, after I specified that they needed to be well lubed many times in communication with the attendees.  I thought they just blew it off, but they had been lubed generously with Frog Lube.  I don't know anything about the company, just what was told to me by the users.

In short, people are still learning that there actually is something to the Military TDP, and it isn't just hype.  My guns in the military worked very well, hardly with malf's ever over 10 years around the world, whether the jungle in Panama, Korea, Middle East, or Europe, let alone Stateside in conditions ranging from humid deciduous forests to dusty, sandy desert.

You will be pitched snake oil sales angles repeatedly throughout life about how this and that is better than what you currently have, when in reality, those parts have not been tested most of the time.  Vent holes on BCG's are not the same as the TDP on many BCG's on the market, the bolts have not been tested the same way, even if they say "MPI" or "MP" on them, cheap gas rings that wear like a pair of Chinese knock-off stone washed jeans, unlined carrier keys, non-inspected MIM'd parts for your LPK, raggedy barrel extensions out of alignment with TDC, weak recoil springs, etc.

You can get a Colt OEM or OEM2 for $700 and change, install some basic furniture, decent optics, grip of your choice, and spend the rest of your hard-earned money on ammunition and quality training, where you will get to see other carbines set up by people who have been doing this for decades, then buy the few other items that fit your needs.

Is Colt selling those as pistols?

Posted Via AR15.Com Mobile

No, they're rifles that just need you to do what most buyers were going to do anyway, which is add their preferred furniture.  I'm not a Colt fanboy, but just throwing out a known gun that works, is affordable, ready to configure.

I also wanted to point out another failure I have seen with home builds.  The Midwest Industries Gen II SS Handguards.  These are great products, but if they aren't attacked securely, they will inch forward with recoil.

Use Blue Loc tite to secure them to the barrel nut, since the bolts only provide so much tension.  Kinda sucks to be shooting along, and watch your rail start to slide off.  Loc-tite'd, they are no problem.

In my experience teaching and working with the AR platform I have seen all of what you mention as well as one manufacturer seems to be more prone to malfunctions and breakage of small parts like hammers, safties and bolt catches and that seems to occur most in the "new" Bushmasters as in those rifles that are made in the Remington plant in NY as opposed to older Bushamsters that were made in Maine.   I agree the AR needs to run wet, but up here in the Northeast it gets cold and some lubes work better than others.  Breakfree CLP has been my old standby for years but I have experimenting with Liberty Gun Lube and so far it works well.    I'll have to test in a few months when the thermometer drops....

I haven't encountered any issues with lubricants in Arctic conditions, with temps down to -30 C.  We keep the guns wet, and fire away.  I personally use Slip2000 EWL, motor oil, CLP, whatever they had up there.

Yes, the new "Bushmaster's" are DPMS internals with Remington barrels, not that the older Bushmaster's were something special in terms of reliability.

You see why the military has call outs in the TDP for parts, specifying materials, treatments, and testing.  LPK components are MPI'd with inspection stamps placed on them on military guns.  If you don't test the parts, something is going to slip through and break, doesn't matter what company name is on the lower.  Bolt catches and trigger pins are notorious for this in crap parts guns.

Spent a bit of time training with the Norwegians and Finns above the Arctic Circle. We used the issue CLP and had no problems whatsoever.

How did those folks look? GTG?

Extremely competent cold weather warriors, very impressive when operating in their element. Several of the MT guys got trucks and hummers stuck......the Nords and Finns would get them right out.  

Spent most of my time in the Corps training with yahoos from 3rd world countries. It was a real pleasure to cross-train with the likes of the Nords, Finns, British Royal Marines and French Foreign Legion........although the FFL are friggin' nuts.

As an aside, I am NOT a cold weather warrior.......to me cold weather is anything much under 55 degrees F!  Did my first 2 years doing jungle patrols in the Philippines.......that's more my element.

@op i agree, most of the stoppages im seeing are in guns that are custom built or modified by the owner, who in most cases doesnt have the skill or tools to do so.

I think its happening for a lot of reasons.
1) its "cool" to build your own rifle.
2) everywhere you look there is some company trying to sell you some after market part you think you have to have
3) you can build a AR15 pretty cheap from used or blemished parts, it saves money but quality may not be the best
4) due to the high cost of all people are not testing their rifles enough. they build, fire a box of ammo and call it gtg

It was only after the first thousand to 1,500 rounds that both ARs I owned started having problems. It might be that you aren't seeing as many malfunctions in beginner level classes as their guns are not to this point in time yet.

most people buy junk. why i dont know.

I've gone through a lot of Wolf (or variations thereon, but not Tula) and for the most part it seems to be at most 1-2 rounds per case.  I've had many more issues with commercial stuff like Winchester than I've ever had with steel cased ammo.  But I do agree that surplus, or ammo loaded for military use seems to be more consistent.

Not sure that one or two rounds justifies the difference in cost, especially for practice and training, if you can otherwise shoot it reliably.  But, know your purpose and what you actually need.  If it doesn't fit your need don't waste your time with it and get something that will.

I took a DMR course and had malfunction problems in a gun that previously ran flawlessly.





Original config:





6.5 Grendel


Sabre Defense upper


Spikes Lower


Geissele SSA-E


PRS stock (I don't know what buffer.)
I realized after the course had ended that the reason for the malfunctions was that I hadn't wanted to lug the extra weight of the PRS around, so I'd swapped lowers, which meant a different buffer/spring combination. (This lower had a Geissele SSA trigger.)  It just never occurred to me during the class that that action had caused the problem.





Dumb and dumber, for sure.  First, like you say, don't change anything on a gun that works.  Second, the answer to 'Why?' was painfully obvious, but it took my poor brain days to think of it.  I mean, the FIRST rule of troubleshooting is:  What changed?

 

People buy economy AR-15 rifle kits and/or parts

1. Because they are cheap.

2. They are convinced because of #1. that all parts are the same and because of that brand name manufacturers are hosing them.

3, I've had people tell me they honestly believe that their airsoft micro red dot is the same as an Aimpoint and that anyone buying a real Aimpoint is an idiot.

4. IMO they deserve crap performance, malfunctions and parts breakage or worse.

You get what you pay for.

Great thread.

I use matches & classes to
ensure that my firearms run
100%. I don't modify them
to make them run "better".
And I don't go to the matches
to win. They are a training
platform for me.

John

OP - do you feel like you have enough data to compare brands based on what you have seen in your courses?

How about relative reliability of gas systems (piston v. DI, or particular brands of various pistons)?

-shooter