M4 and reliability: Debunking the piston myth

[KChen986]

Re: Muzzlecaps.

If you ever had to fire your M4, did you just shoot through the muzzlecap?

Also, which portion of the rifle did you focus the rinse on?

Thanks. This might help me out a lot.

 

[kraigwy]

Re: Muzzlecaps.

If you ever had to fire your M4, did you just shoot through the muzzlecap?

Also, which portion of the rifle did you focus the rinse on?

The first round will take the muzzle cap off. I could be deflected a tad but wouldn't matter if firing a burst. If a precision shot is desired, the you normally have time to take the cap off first. Some use tape. It works the same way. Muzzle caps are a one time shot.

As for water, if the gun is just being washed off from dust, the pop it open, rinse off the bolt and chamber area letting it drain out the rear of the receiver.

If the gun is hot, then flood the outside of the action and barrel. We even peed on '60 barrels in SE Asia.

I've taken 1911a1's and stuck them in water and swished them, washing off mud. Never had to take a 1911 apart. Just make sure there is no mud in the barrel and keep it out of the mags and it will keep running for you,

Never shot an M-9 enough in those conditions to advise on those.

The M16 series is pretty easy to keep running if one just thinks about it a bit. Main thing is to keep debris out of your mags.

 

[Rob3]

HorseSoldier, I agree I would like to see a much more detailed view of what the survey actually found. You are right about the SAWs needing to be replaced, Infantry Branch decided last year to begin replacing all SAWs with new ones as they have found that nearly all SAWs in the inventory are worn out. M9s don't seem to be viewed as a critical combat weapon so it is doubtful they will be replaced any time soon.

There is an interesting story in Army Times about coming changes this year.

http://www.armytimes.com/news/2011/01/army-what-to-expect-in-2011-010111w/

Scroll down to the bottom and it covers some of the coming weapon changes. Testing for new carbines begins this month. Colt has even submitted a "hybrid piston" design. It seems that the issue of changing carbines is a very sensative issue not just with soldiers but politicians alike. Colt has some powerful senators on it's side and was quick to file lawsuits to block the Infantry Branch from adopting the XM8. The Army now owns the patents to the M4 and has stated that they will never sign another contract again like the one with Colt. It will be interesting to see what comes out of the new tests and what the Army decides.

 

[tirod]

Chindo, thanks, it's always more credible coming from a user rather than quoting an FM. We DON'T have to do nothing about the dust issue. And the fixes are very similar to what was taught in the early '70's. Don't let the stuff in, clean it out, keep it lubed, it keeps running.

Nice link to the Army Time article. If you go there, just before the Improved Carbine paragraph is a quick note on 5.56 telescoped plastic case ammo. That's the LSAT round, which apparently still has enough merit to pursue further development.

As a weight reducer, it could be considered a major improvement, and that action uses the shuttle bolt, not a traditional carrier that chambers and ejects. What you get is a much shorter action, 50% more ammo, in a straight feed magazine. Battalion level testing was announced for scheduled testing, and SOCOM has also signed on for the same. Which means, there is potentially a few HUNDRED prototype weapons out there. The Squad MG is on youtube firing at the range, old video from last year.

The Improved Carbine submittals did not rule out a different caliber, it remains to be seen if the LSAT shows up or is still years out.

 

[Skans]

One thing I've learned is there is nothing wrong with the M16/AR system, its the idiots operating them.

Everyone can be an idiot. Most everyone has performed at least a handful of idiot things when handling this or that gun. In the grand scheme of things, I'd rather have an idiot-proof gun than one that is easily screwed up because some "idiot" move I make.

If a piston system permits me to shoot longer with a dirtier rifle, then IMHO, it's a good system. If its more finicky about ammo than the DGI system, then it's not a good system. The bottom line is to seek out whatever it takes to to get accuracy, dependability, ruggedness, serviceability, and power into an easily carried well-fitting firearm.

 

[Bartholomew Roberts]

You are correct about the recent survey which found that only 19% of soldeirs in Afghanistan have experienced stoppages. However, if you extropolate that out to troop levels when the survey was taken that equals at least 20,000 stoppages in combat.

The CNA survey also found that 1/3 of survey participants (all soldiers with 5 or more combat engagements) were not issued cleaning kits and that rebuilt/reconditioned rifles were 3.5 times more likely to have a stoppage.

So right away, we have two big clues regarding the source of stoppages in the CNA survey and neither one of them have to do with the basic design of the M4 but a lot to do with how it is maintained and serviced.

HorseSoldier, I agree I would like to see a much more detailed view of what the survey actually found.

Earlier in the thread, theinvisibleheart posted a link to the actual CNA Survey Report and the link I posted to the USNI Proceedings article on the Battle of Wanat summarizes the CNA survey and several other evaluations of the M4.

Colt has some powerful senators on it's side and was quick to file lawsuits to block the Infantry Branch from adopting the XM8. The Army now owns the patents to the M4 and has stated that they will never sign another contract again like the one with Colt.

Colt can not block the Infantry from choosing the XM8 if that is what they wanted to do. What Colt can do (and did) was complain that the XM29 program was different enough from the XM8, that the Infantry branch should be forced to have an open competition if they wanted to adopt a new rifle. Which is pretty much the same thing other manufacturers argued when the tried to block the Army from replacing the M16 with the M4 on a more widespread basis.

And the patent/TDP wasn't result of a contract between the Army and Colt - it was a settlement of a lawsuit from the 1990s where Colt sued the Army for releasing the TDP for the M4 to several competitors.

Ultimately, Congress got tired of the bickering and now you are going to see that open competition - which should be great news for all rifle enthusiasts as we will get to see improved designs and hopefully get some better information on extreme performance that few of us can afford to test on that level.

 

[10mmAuto]

The Army now owns the patents to the M4 and has stated that they will never sign another contract again like the one with Colt. It will be interesting to see what comes out of the new tests and what the Army decides.

No matter what the chart says, there's something in the execution of Colt manufacturing that leaves something to be desired. Of all the "Acceptable fighting rifles", they're clearly the worst. I'd put them on par with DPMS and other hobby gun brands. They're not bad guns but compared to your average BCM or Noveske which are supposedly in the same quality range I'm not impressed.

So right away, we have two big clues regarding the source of stoppages in the CNA survey and neither one of them have to do with the basic design of the M4 but a lot to do with how it is maintained and serviced.

This supports the "researcher" in the OP's article - that the primary cause of malfunctions was worn out weapons.

 

[Chindo18Z]

KChen986: 1. "If you ever had to fire your M4, did you just shoot through the muzzlecap? 2. Also, which portion of the rifle did you focus the rinse on?"

1. Just shot right through it. It's a cheap piece of plastic and disappears with the first shot. You won't even notice.

2. I'm with kraigwy on this...Just swish the damn thing into or under any available water that is marginally cleaner than what you are trying to get rid of. Stream, lake, pond, river, creek, swamp, rice paddy, canal, drainage ditch, puddle, sink, faucet, 5-gallon can, water bottle...any water source.

Military weapons get wet all the time in a field environment. No big deal. Back when I lived in the barracks, most of the folks in my Infantry platoon simply took our weapons into the showers upon return from the field. Do an initial weapons flush and scrub with hot water and soap. Wipe dry. Complete cleaning with bore cleaner or CLP as needed. We cleaned the weapons with the pressurized hot shower water before we even started to clean the grime from ourselves.

When I refer to flushing a weapon in a desert environment (which BTW, can also get incredibly muddy after rain), I'm talking about being unable to get rid of dirt, dust, sand, or mud with a dry shaving brush. In that case, I'm simply pouring some water into the trigger housing group to rinse out the crud and shake the water out. Add some oil or CLP. Done. Same with BCG or upper/chamber (if needed).

98% of the time, a few seconds work with a dry shaving brush will remove most any sand or dust satisfactorily. This simple procedure works for ALL small arms and is not unique to the AR system. Weapons get dirty in the field, whether fired or not.

I'm not in the habit of wasting water as a matter of course in a hot/dry environment. But, if you need to wash off your weapon, just do so. Hell, like kraigwy suggested...if you need to you can just pee on it (for cooling or to remove wet sand).

The amazing secret of most militarily successful general issue small arms is that they are designed for extended and reliable usage by untrained peasants or conscripts under crappy conditions.

They mostly all work pretty well. M1 Garands, M16s, AKMs, M2s, 1911s, Makarovs, FALs, BHPs, Glocks, M14s, SKSs, Mauser 98s, etc. ....THEY ALL WORK under atrocious conditions. They are DESIGNED to.

 

[theinvisibleheart]

Bartholomew Roberts, re: post

1. reasoning by internet links

You can find web links/posts to support anything, from curing cancer by diet to making phenomenal returns based on pyramid schemes. Not only that, you can see in this thread, as well as others, lack of even elementary understanding about general design or test principles.

Furthermore, not everything in this world is duplicated in web space(that's why we still have printed publication).

According to small arms design text "Small Arms: General Design" by Allsop/Toomey, gas impingement system such as those used on AR15/M16 suffer from:

The main drawback is that carbon particles are deposited all around the breech head and these become hard on cooling.

Then the text goes on further to say that gas impingement system weapon which is not cleaned frequently is liable for more stoppages.

Here are the facts about gas impingement system:
- it gets dirtier compared to gas piston system(increased rate of fouling)
- the system runs hotter

Basic engineering principle: a system which runs hotter and suffers from increased rate of fouling also suffers from decreased durability and reliability.

Heat accelerates tear and wear, both in electronics and mechanical systems, all things being equal.

System which gets dirtier faster also suffers from increased tear and wear, as well as decreased reliability. You can easily see this when you have more foreign element in the chamber...how it decreases reliability and increases rate of tear and wear.

If you don't believe any of this, don't change the oil in your car and see how well it functions.

Or better yet, pour foreign element(gunk) into engine oil and pour it into your engine, and see if reliability/durability changes or not, LOL.

Or better yet, disable the fan in your desktop/laptop and see what happens to your computer, LOL.


2. D.C. Capitol Police switching from G36 to M4

Unless DC Capitol Police changed to M4 because G36 was UNRELIABLE and M4 WAS RELIABLE, it doesn't have any relevance.


3. evidences that gas piston is more reliable than gas impingement system

a. according to IDF, IDF chose Tavor over M4/M16 in field trial because Tavor showed increased, not less or equal, reliability when compared to M4/M16 that they get for very little money(Tavor cost them much more since they don't get it in foreign assistance like M4/M16).

Financial incentive for IDF is to stick with M4/M16 platform since they can get it for little or no money from US, not switch over to Tavor.

b. in US military trial, gas piston XM8 showed more reliability when compared to M4. XM8 is based on G36, and G36 in turn is based on AR-18.


c. basic engineering principles:
i. cooler system are more reliable/durable compared to system which runs hotter, all things being equal
ii. cleaner system are more reliable/durable compared to system which tends to run dirtier, all things being equal

These basic engineering principles applies to cars, electronics, and also to firearms.

It's also why flaws in AR15/M16/M4 system becomes more evident in operation in dusty environment and during full auto fire.


4. assertion that M4/M16 is super durable/reliable because samples from 1960s still exist today and works, and is being used by people such as Montagnards

Unless those M4/M16s are either 100% or mostly original parts, it's meaningless. There are cars from 1930s/1940s/1950s still running today, but if they were driven regularly, were basically rebuilt so much that they are essentially new vehicles.

If you keep on replacing and rebuilding parts, you can make most things last forever. My question is that how much cannibalization Montagnards had to do to keep on making their M16 work.

My bet is that Capt. Self's M4 was rebuilt so much that it was essentially a NEW gun.

I've shot at least 3 different AR-180 that were 30+ years old, ranging from mint to heavily used/beatup. They were either 100% or close to 100%(mostly original parts). They never malfunctioned despite firing rounds after rounds w/o ANY CLEANING and was cooler, compared to AR/M16 platform.

Does that mean all gas piston platform is perfect? No, it doesn't. But at least the OPERATING PART is superior to that of gas impingement system.

theinvisibleheart, first of all, it isn't necessary to quote my entire post, especially when it the post immediately above yours. Feel free not to quote me at all, I'll figure it out.

Second, I'm not interested in you rehashing what you thought you read somewhere. Too often, someone's interpretation of what a study said or what a test showed is at best speculative and at worst flawed.

I'm also not interested in your opinion. I don't mean that in a rude way or a demeaning way; but opinions are cheap and easily available. I am more interested in the facts that you used to form your opinion - more particularly the direct source where you acquired that information. If you'd like to share facts, in the form of links to readily available information, citations, etc., then I am always interested in learning.

Quote:
I doubt Bundeswehr using G36 are having 19% of their combatants experience failure in field like M4.
And you base these doubts on what? Considering the G36 didn't live up to the demanding needs of the D.C. Capitol Police, I wouldn't be too quick to make that assumption. (<-- See what I did there - instead of just typing that the Capitol Police ditched their G36s for Rock River ARs, I gave you a link to where I heard that so you can evaluate it firsthand)

Quote:
That's facetious at best because you are taking an exception, rather than the norm, as being representative.
No, I was taking two rifles that based around the AR-18 gas system since that is what you mentioned earlier. A lot more goes into reliability than the gas system.

Quote:
Most gas piston system such as Tavor, SAR-21, G36, etc. are highly reliable.
Most direct gas systems, such as the M4 and M16 are highly reliable (HKGuns link from earlier in the thread mentions 5,000 mean rounds between stoppage). You apparently seem to be of the belief that these other systems are more reliable than the M4; which is great; but I'm not looking for belief, I'm looking for empirical evidence. Do you have any of that?

 

[theinvisibleheart]

HorseSoldier, re: M249/M9

Belt-fed GPMG's action is more exposed due to belts being exposed. Ditto for M9's super exposed slide.

I wouldn't compare belt-fed GPMG and open slide M9 to assault rifle.

It's not even "keep it cleaned and oiled" it's simply "keep it oiled." And the 19% who experienced stoppages were not sorted for causation of the stoppages -- bad magazines have always been the primary issue with the weapon system, and there's no notation of how many stoppages in that survery were attributable to substandard supply sergeants reissuing worn out junk magazines. No break down by what percentage may have been attributable to other causes, as well (bad ammo is rare, but does slip through QC sometimes, etc).

So the figure overall doesn't really tell us anything and certainly doesn't implicate the M4's operating system as flawed. The piston driven SAW doesn't clock great results in the same study, not does the recoil operated M9.

 

[theinvisibleheart]

Rob3/others, muzzle cap solution

Putting a garbage bag over the entire gun is a better solution than muzzle cap, until you need to operate, in the case of very fine sand/dust environment.

Off course, it's only an interim solution.

I don't see how always cleaning a gun is possible esp. since in theory, the gun should be cleaned before it cools down(carbon particle becoming hard on cooling).

I'm making an assumption that you can't always assume that when your gun cooled down, the enemy won't attack.

We all understand the concept that if you keep it clean and oiled the M4 will run forever. Soldiers have been told this since Vietnam. We got it.

The problem is that this is not always possible, and when an M4 gets water, snow, sand, dust, mud, or excessive carbon in the action it will have a lot of stoppages and there is little a soldier in a bad situation can do to fix quickly and safely. The same may or may not be true for any gun. I think it is a great idea that the Army has chosen to start another round of tests now that it owns the patents and cannot be sued by Colt. May the best gun win and get in the hands of soldiers ASAP. If it's the M4, great. If not, we will have something new to bitch about.

Magazines are a problem too, got it. Most soldiers have access to PMAGs if they want them. Some units issue them, they are sold in SSSC stores and I have even seen them for sale in the PX at KAF. Plus there is always the internet and mail.

 

[theinvisibleheart]

soldiers' confidence

it's the purpose of military, for the sake of morale, to always train soldiers so that they would have utmost confidence in their weapons, whether justified or not.

I wouldn't place too much weight on soldiers' confidence being reflective of weapons' reliability.

If the DI is doing his duty, then even soldiers armed with single shot rifles should have confidence, LOL.

In WWII, US military released a film, trying to teach US military soldiers that they shouldn't fear Hitler's buzzsaw(MG-42) in action. Later, I listened to an interview of one German MG-42 machine gunner who killed over 5,000 GIs on D-day with his MG-42 before being forced to retreat.

 

[theinvisibleheart]

Brenten, re: piston lasting longer

gas piston system last longer because it's runs cooler and cleaner, for the same reason your car engine lasts longer if it runs cooler and cleaner.

as for those that say a piston will last longer before stopping without cleaning, I will agree if that piston is the sloppy loose AK-47. The tight accurate AR design pays a price for being accurate. Having said that I have had the best AK's jam on me.

 

[theinvisibleheart]

tirod, re: Montagnards?

The question I have is how much of those original M16 was all original parts that came with the rifle?

My bet is that they were heavily cannibalized.

My bet also is that Capt. Self's M4 was rebuilt so many times as to essentially be a new gun(except for the receiver).

If I'm not mistaken, there are still running Ford Model T, although not with 100% original parts, as it came from factory.

That doesn't mean we should stick with Ford Model T TODAY.

Functional M16's are purchased from Montagnards with heavy wear and still fire. They were issued to them in the late 60's/early '70s, and that one anecdotal story is equal to one old AK.

The issue is that some don't want to believe the DI system works, and point to equally uninformed opinion that gas systems do. It's been my experience there is too much belief and not much analysis and thought by most gun users. DI or Piston, the Stoner design has other attributes that are MORE important.

The barrel extension eliminates the heavy receiver and contributes a significant weight savings. The Aluminum and composite construction eliminates time consuming cleaning of a carbon steel receiver that can rust on any surface. The stocks don't warp, get heavier when wet, or rot. Operator controls are based on ergonomic use. The simple addition of a working bolt hold open on the last shot improves speed of reloading and the reliability of chambering the first round. Tap the bolt release, it loads. You don't have to insert against a closed bolt and drag it over the loaded magazine before even getting your hand back on the trigger.

The anecdotal stories of "My weapon jammed so I threw it down and ran for another." raises the question, is that doctrine? Do we now teach that in Basic, and is there additional higher skill level training for E5/above in specialty skills? Do SF/Ranger/Delta/Seal teams practice the Jam and Run? What happened to just clearing the action, if necessary by dropping the mag, rather than disarming oneself and turning their back on the enemy?

I take serious issue with any report of negligent or inadequate training as a basis for the weapon being at fault. With that lack of tactical expertise, please tell me that weapons maintenance wasn't equally affected by the supervisor's leadership. Are we so overloaded with administrivia that no one cleaned, function checked, and tested the weapon was ready for service?

Oh, it's the dust, it gets everywhere. Excuse me, fix the problem. Don't let dust get in. The operator seems dead set on the weapon fending for itself. Jams, throw it down and get the one that does work because that soldier did a better job of it, or just complain.

WE ARE THE ONES with choppers, MRAP's, HMMV's, etc churning up the countryside. Haji? On foot or a pickup truck. Does Haji eat dust all day? No, his AK sits under cover until he needs it. Maybe our problem isn't the M4, it's the unequal way we are stuck with the conditions.

There are specific dust fixes, which ones get used?

 

[thesheepdog]

gas piston system last longer because it's runs cooler and cleaner, for the same reason your car engine lasts longer if it runs cooler and cleaner.

Umm...incorrect. A piston is subject to the same ammount of heat as a DI system.
You have to think hard on this one; where does all that hot gas go when you fire a round on an AK? The MAIN difference between the GP and DI system is that a GP system dispenses of the hot gas; preventing it from going in the chamber. A hot piston can break just as easily as a hot BCG.

Also, a DI system is a piston system; it's just that the BCG utilizes the hot gas to cycle the action, rather than an Op-Rod.
Pistons contain more parts as well, so more parts are subject to wear; leading to more wear and more breakage.

 

[theinvisibleheart]

thesheepdog, correction

I was referring to the chamber, LOL.

THINK!

It's cooler in the chamber (for gas piston) because dirty gas/powder residue doesn't go back into the chamber in the case of gas piston.

As for fouling, shoot AR-180 and compare it to AR15, and see how much cleaner AR-180 is.

XM8 is a derivative of G36. G36 is a derivative of AR-18/180.

As for rest of your assertions, if true, then

M4/AR15/M16 should be CLEANER and MORE RELIABLE and COOLER than XM8, G36, Tavor, AR-18/180, etc.

If that is the case, how come AR15/M16/M4 system is dirtier when you clean them side-by-side?

#95
thesheepdog
Senior Member

Join Date: May 12, 2010
Location: in the not so cool state of Texas
Posts: 1,507
Quote:
gas piston system last longer because it's runs cooler and cleaner, for the same reason your car engine lasts longer if it runs cooler and cleaner.
Umm...incorrect. A piston is subject to the same ammount of heat as a DI system.
You have to think hard on this one; where does all that hot gas go when you fire a round on an AK? The MAIN difference between the GP and DI system is that a GP system dispenses of the hot gas; preventing it from going in the chamber. A hot piston can break just as easily as a hot BCG.

Also, a DI system is a piston system; it's just that the BCG utilizes the hot gas to cycle the action, rather than an Op-Rod.
Pistons contain more parts as well, so more parts are subject to wear; leading to more wear and more breakage.

 

[thesheepdog]

I was referring to the chamber, LOL.

THINK!

It's cooler in the chamber (for gas piston) because dirty gas/powder residue doesn't go back into the chamber in the case of gas piston.

As for fouling, shoot AR-180 and compare it to AR15, and see how much cleaner AR-180 is.

True. The chamber usually does stay cooler on a GP weapon. But, how much cooler? Eventually-when firing loads and loads of ammo-the entire weapon will heat up-even on a GP system.

Have you ever seen how a turbo works on a engine? It uses the hot exhaust from the cylinders to force air back in the combustion chambers-giving you much more power and added benefit. But if overused without an intercooler, you'll burn up your engine.
The DI gas system is the same way. It uses the ready supply of energy-hot gas-to cycle the bolt.

Now if your parts aren't well made, then it won't matter whether you have a piston or not, something will break.
But on mil spec weapons, then parts are pretty high quality. So it's expected that heat doesn't affect the parts.

If that is the case, how come AR15/M16/M4 system is dirtier when you clean them side-by-side?

I had a Mini-14 that ran twice as dirty as my current M4. I think you misconcieve how clean modern ammo is these days. You keeping your thoughts back in the day of corrosive ammo for the M16.
Chambers will get dirty eventually, and that's why we have cleaning kits; Gas piston or not.
I'll add to that, I'd rather have hot gas blowing filt out of my chamber than not having it in there.

 

[theinvisibleheart]

thesheepdog

I have to go but:

1. I've shot Mini-14(old versions). AR system does get dirtier/hotter in chamber due to gas impingement.

Problem with old Mini-14(lack of accuracy) has more to do with manufacturing/quality control than gas piston system.

2. you want to keep gas/powder residue separate from chamber since more fouling/heat in the chamber will increase rate of tear and wear.

Again, you have to make sure that all other factors, including quality of components, are same.

3. turbo charging on cars: if both cars have turbo charging and are same in all other aspect, then the one with cooler/cleaner engine will last longer.


4. I think you misunderstand again. The problem is not hot gas/powder residue cleaning the chamber but

i. making it more dirty(gas coming in carries with it more dirt and hot air as well)
ii. increasing heat which will raise rate of tear and wear

I'll add to that, I'd rather have hot gas blowing filt out of my chamber than not having it in there.

 

[thesheepdog]

invisibleheart,

What difference does it make? A DI system is a piston system. But the nice thing about the AR-15 is your don't have to remove the handguard to clean/repair/inspect your piston.

My Mini-14 got so filthy that the black residue wouldn't come off the stainless steel-as I mentioned already in a previous post.

then the one with cooler/cleaner engine will last longer.

Nope, the one with the highest quality parts will.
You can run a Honda Civic at 230 degrees longer than you can run a Ford Focus at 180 degrees.

 

[.22lr]

I went to Rensselaer Polytechnic Institute where I earned my BSEE (Bachelor’s of Science, Electrical Engineering) in 2001. I have worked as an engineer for the past 9.5 (ish) years.

Basic engineering principle: a system which runs hotter and suffers from increased rate of fouling also suffers from decreased durability and reliability.

1) Cite your source. I must have missed the class where the universal rules of thumb were handed out. Some systems run better when brought to operating temperature.

2) It is all a matter of degree. By citing your rule of thumb you have left out any actual measure! Does it matter? What are the operating temperatures of the two different systems? How fast does a Direct Impingement system wear out? How fast does a Piston system wear out? Without actual measurement, it is all meaningless!

3) Environmental contaminants (dust, blown primers, twigs, spider nests) have a MUCH larger impact than fouling! REGARDLESS OF OPERATING SYSTEM! the action being covered in a fine dust will wear out / choke a weapon system way before fouling.

4) MANY of the weapons that are cited as "unreliable" are way beyond their design life. They are worn out. Time doesn't wear out guns, USE DOES! If you never wear out your gun, you haven't used it enough.

5) The hottest part of ANY gunpowder-powered projectile weapon system will be the barrel! The barrel heats much faster than the action. In automatic arms, the barrel heat can be such that the barrel will weaken and burst. Rounds will cook off in the chamber before fouling stops a weapon. Action temperature is largely a red herring

6) Lubrication is usually a good thing. Increased wear is usually bad. Lubricate your weapon system.


-Pick a weapon
-Learn the weapon
-Maintain the weapon
-STOP WORRYING!

--A properly built and maintained weapon system will outlast the vast majority of users. For those that run their system hard: maintain it, check it, and when it exceeds its useful life, replace it! And by replace it, i don't mean with a new design, but with the same design that you learned to use and maintain. Why start over at 0 just to get some "improvement" that can only be spoken of theoretically, and seldom if ever quantified?​

Please note: I haven't stated a preference of Direct Impingement vice Piston. It really doesn't matter in the grand scheme of things! Learning to use and maintain your chosen weapon system well does!