AR-15s are the weapon people want to get when they haven't used one extensively. I hate the AR15 platform. It's dirty, prone to jamming, not a bullpup, and the little compartment on the back of the stock is the biggest bitch to open up.
Joined to interject my 2 cents on these comments right here, I not here to attack anyone or the F2000, because I think is shows promise, but I will say its nowhere near as proven as the AR-15 platform is.
And yes, I know this is my first post here, would of just kept lurking, but based on MY extensive use of the AR-15 platform, I'm going attempt to clear some things right up. Prepare for a lot of text, I'll try to sum a TL:DR at the end.
Also while I address Korban's complaints directly I hope with will be useful information to all about the platform.
My Background(s):
-12 & 1/2 Years with the Army National Guard - Including; one deployment to Iraq(2003), two deployments to Afghanistan (2009 & 2011), Multiple Stateside 'deployments', Katrina in 2005, multiple wild fire incidents in California, three years with the additional duty of being my unit's Armorer (hundreds of M16's and M4's in my care, not to mention M9's, M249 SAW's, Mk19's), time as a member of an an MP Entry Team, and countless ranges, training sessions, etc. were I've taught and overseen the usage of the the AR-15 platform.
-Concurrently had Six Years with DOD Law Enforcement - Managing to finagle a California POST Firearms Instructor certification out of my time there, being one of the Department's Firearms and Tactics Instructors(obviously), a Senior Officer/Field Training Officer, and time on the Department's Entry Team.
-Civilian wise I'm a hobby firearm tinkerer/assembler(I've been attempting to find a suitable gunsmith school to use my GI Bill on, relocation issues have been making this difficult), I've built my own AR-15, cherry picking and assembling every part but the putting the barrel extension on the barrel(requires press), assisted two friends with their AR-15 builds, and one with a AR-10, consulted on about a dozen or more other builds, done my own Saiga 922(r) conversion, some custom cutting and fitting on a favored revolver, and plenty of 'non-invasive' addons to many other weapons.
The AR-15:
As evidenced above I have an extensive amount of time hands on with the AR-15 platform. Most of the complaint's I've seen stem from; improper long term care of the firearm, operator errors of multiple types, ghosts and misinformation from previous/early incarnations of the platform and its attachments.
I'll try to address each fault listed, but some of them have multiple causes, and a lot of experiences will be chalked up to the rifle being an if not old then thoroughly used military service rifle.
Dirty The AR-15's receivers are not much more open to outside contaminants than many of its contemporaries; AK,FAL,G3,FAMAS,etc. Most of these have a mag well, an ejection port(many of them larger than the AR's), and some form of receiver separation(AR upper/lower, AK top cover), that are the primary points of entry for outside contaminants. Granted, the AR's internal tolerances are pretty tight comparatively so there's that.
I'm going to assume however by Dirty you mean the AR's gas impingement system, where the weapon operates by directing expanding gases from the barrel through a tube into the bolt carrier group. Alas, most of the issues here come from 'user' problems, I use that term lightly as opposed to say, design problems. The two main problems I've seen on the military side are that; 1) Stoner did not intend for the military to use such a foul burning powder in their rounds, and 2) Most military AR-15 users WAY over lubricate their rifle, in an effort to "avoid" jams. However this over abundance of lubrication, usually in the wrong spot too, actually soaks up carbon from the operating gas and forms a sludge that mucks up operation and, after enough carbon is soaked up and heat applied, turns into a rock hard crust that is hard as hell to remove.
Also over lubrication and the resulting gunk exacerbates the problem with outside contaminants, military pattern AR-15 rifle's tolerances are actually rather loose to accommodate
some outside contamination, just not the amount you get when lube is acting as a 'dirt magnet'. Obviously there is the common anecdote where someone throws a handful of dirt into an AR and an AK and the "AK keeps working", while it does show the AK's reliability well, when was the last time you decided this was a good pre-gunfight step?
Prone to Jams Apart from over lubrication causing gunk mentioned above, there's a couple other things that lead to the weapon being "prone" to jams. A big one, magazines, chiefly cheap ones, or even good ones that have been in service way too long, something the military is notorious for.
There's anecdotes of 28 round mags, yeah they work, but your mag was supposedly designed for 30 rounds, if that's not working, probably need a new mag or at least a new spring/follower. Mag going into the mag well to far? The top of the mag wall's are soft, either cheap or worn out. Double feeds a lot? Mag lips are worn, again cheap/worn. Bumping mag on stuff or trying to 'monopod' your rifle on the mag causing problems? Need a newer mag, either its too old for that or it's cheap and/or worn, some of the company's now-a-days are coming out with mags designed to monopod, Magpul's Pmag comes to mind, I've also seen new military issue mags with a literally brown in color Brownells follower that could mono, I'm thinking the whole mag might have been from Brownells, but I'm not sure.
Mags should be good condition and clean, this means all the parts, body, spring follower and even the base plate. Another thing that makes you look at your mags, tension of the mag release assembly. Too tight its hard to get mag in all the way, you will think you have it and you don't. Too loose and the mag will slip out or ride low, though riding low is very uncommon, usually just falls out.
Not a Bullpup Well, you've got me there, as far as I've seen a bullpup conversion is impractical, due to the buffer, spring and tube. Unless it was done on a forward recoil variation like a ZM LR300, but then somebody's just got too much money. I don't personally own a bullpup, and the only play time I've gotten with one was some non-firing time with some British soldier's L85's(SA80) and LSW's, and I got to fondle a Tavor last month for all of 5 minutes, seemed real nice though.
There are benefits to both styles, bullpups are nice for their shorter overall length while retaining barrel length, usually recoil better due to overall weight balance, balance and length also usually make them easier to handle in close quarters, vehicles, one handed, etc. Bullpup con range from usually suffering from mushy triggers due rods connecting trigger to action, reloading the mag in your armpit(I'd say this is more a training and practice issue, but I'm scratching my head on how to keep a bullpup aimed at something while doing a planned reload.) Bullpups usually have their sight line raised from the barrel significantly over their traditional counterparts.
Traditional rifles like the AR and AK usually wont get anywhere near a bullpups short length without a significant loss of barrel length and/or butt stock length of pull. From what I heard from the Brits I've talked to the L85 is a pain to fire from the prone, so traditional rifles have a small benefit there due to shape, but most people who are not made to fire in the prone don't, so I'm not sure that's much of a selling point. I'd say the biggest thing the AR as over bullpups at this point is is familiarity of use, worldwide people have been used to traditional rifle patterns for a long time. I also feel that reloads and clearing malfunctions on AR-15 and friends would be easier than bullpups, due to everything being in front of you at arms length, rather than right up next to you, but again that's probably more of a training issue than a design issue.
Buttstock Compartment Yeah, those blow. That "A2 Variation" buttstock is all kinds of annoying, not just the compartment door, but also seen many shear a plastic stud where the stock meets the lower receiver below the buffer tube, stock ends up rotating freely on buffer tube like a eccentric clock. As far as the compartment door, most soldiers I've seen don't bother to put anything in there, even the cleaning kit designed for it is a bitch to even fit in sometimes, let alone get out. Only saving grace I can say for the AR-15 is this; thank god this stock is usually only on the M16's and select civilian models, models that you can usually choose a different option on. There is also a plethora of quality aftermarket full and collapsible stocks out there, some are very reasonably priced, and they are not hard to replace. Dinging the entire platform on this one variant/line's crappy butt stock compartment door is like saying a muscle car isn't fast because its got the wrong color paint.
Wobble/Tightness I'm assuming you are referring to typical upper/lower receiver slop present in most military AR platforms. Yeah, its annoying as dog shit I know, shake the rifle and you can hear a very audible "clacka clacka" and often see a gap between the two receivers. Funny thing is, new/refurbished military and new civilian AR's typically don't have this. If a new one does, its from an extremely cheap manufacturer. There a factory tolerances for how every part on an AR should fit together, including the upper/lower, and extreme amount of gap is out of tolerance and shouldn't be sold. Typically this wobble and gap is cause by long periods of use(military rifles that have seen probably a 100 soldiers before you) and/or improper care.
In military ARs the "whole hell of a lot of previous owners" and improper care go hand in hand, also the improper care I will describe goes affects the previous paragraphs as well, improperly care for mags, cleaning procedures. Improper care can be a number of things, soldiers, marines, airmen, and NCO's from every branch all have their "tricks" for cleaning ARs "quickly" and "efficiently". The problem is most of these tricks are horrible for the weapons, especially when you consider all the "men your rifle already slept with". I've seen everything from improper cleaning solutions, like brake cleaner, Simple Green floor cleaner, abrasive compounds(stuff with sand and other 'grits'), all these are bad by not only stripping away protected oils and other permanent coatings(anodizing, bluing), but also because service members typically don't make sure this stuff all gets out and replacing the oils that were removed, oils (typically good old CLP) are critical in long term protection any metal firearm part.
Some of the other "tricks" involved tools, I've seen everything from hard steel brushes, inappropriate scraping tools, even power tools like sanders, drills with wire wheels, and Dremel tools, usually with wire heads, sometimes grinding heads, very rarely polishing heads(which can be ok, but are typically unnecessary). Its basic forensics that when any two objects touch they leave traces on each other, in machining and metallurgy the truth is this: The harder object takes pieces off the softer object. So all the steel brushes, inappropriate scrapers, power tools(speed and repetition can make softer materials still mess up harder ones) slowly damage a rifle. Most of it is so minute its not noticed, but again, this times how many of those 100 soldiers?
The last thing in the cleaning category is the military's standards of cleanliness. "Sergeant always wants my rifle parade clean." Well, parade clean involves scrubbing the hell out of your rifle, keeping it very dry if not as devoid of lubricants as you can get, and is usually far cleaner than necessary for very reliable service operation. Sergeants, Drill Instructors, Arms Room personnel are all notorious for the "white glove inspection" (sometimes being a q-tip or cotton ball inspection). As firearms are used the carbon from firing and the oil for lubricating soak into the metal, as you clean the rifle you get the surface deposits and nasty built up carbon out. But the soaked in stuff is in there really good, and it's not really hurting anything, but when you re-apply fresh lubricant it soaks some of the old carbon out, and the new lube darkens, quite often blackens. So then the white glove or q-tip gets passed over you weapon it comes way at a minimum lightly gray, sometimes wet black.
The only way for Private Joe Snuffy to not get dinged at the inspection is to scrub the ever living hell out of his rifle, probably using methods, products and tools described above to get that "extra edge", and then doesn't re-lube his rifle. Even worse, some arms room's require soldiers to turn in their weapons dry, on the chance some brass will come through later and find "dirty weapons" because the lube soaked carbon out. Also this lube soaking carbon out thing is pretty slow process, and think of how many rounds any one military rifle has seem through it, the whole thing is kind of like ice skating uphill. So those of you who would suggest repeated soakings? I've never seen someone get ALL the carbon out, its quite literally not possible.
All of these "tricks" and improper tools/techniques not only affect receiver wobble, but internal tolerances, bolt/chamber head-space, basically everything on the gun.
Last thing I will touch on in long term care, not everyone servicing that rifle at a unit direct support(arms room), or higher(direct maintenance, depot) cares to do their job to the best of their ability. My last deployment my issued M4 carbine had a Knight's Armament Rail standard(if it had had standard plastic hand guards I probably would not have noticed this). The rail was very slightly canted(about 5-10 degrees) to the 11 o'clock position, being that the rail attached to the barrel nut this told me that the barrel nut was either too tight or too loose.
I talked to arms room personnel at my original unit and the unit I transferred too, and direct support maintenance at both my National Guard and Active Duty pre-mobilization sites, explaining what I thought was wrong, and that I could even fix it myself but I did not have access to a vise. Everyone told me the rifle was fine. When I got to Afghanistan we had a civilian contractor ran arms room as part of our support element, I took the rifle to them and explained it, the guy said "oh yeah exactly, and it if it's not that I have another idea what it might be." He told me to come back in an hour. When I got back he told me it wasn't the barrel nut, it was the upper receiver, the opening in the receiver where the barrel extension seated into was waaaaaay out of tolerance(it was oval shaped), thus when whoever screwed the barrel nut on and torqued it down the nut was not only on crooked, but the barrel was also not aligned properly to the weapon, explaining repeated issues I had zeroing the weapon and why my sights were almost bottomed out and adjusted all the way to one side.
Simple fix: new upper receiver, took all the parts out of the old one(sans a new barrel nut), he had had it done in about a half hour and spent the next half hour testing it. It took four months, talking to two unit armorers and 4 different direct support people(both locations the first guy was like "huh?") and actually ending up IN theater with a rifle that shouldn't have been deployed, before someone else realized the problem and took an hour to fix it.
Also for 'eventual' (it shouldn't happen if you buy quality and take care of
your(Civ) rifle, even the "clacka clacka" test is bad done a million times) wobble, there is an aftermarket product called an Accu-Wegde, they are cheap, awesome little silicon inserts that you put in the lower receiver, takes most if not all wobble out. Some company's are even designing adjustable systems into their new rifles to combat wobble. Also as a final though, wobble while annoying and bad for the moving parts,
debate-ably, should not affect accuracy, everything that sights and makes the bullet go in the in the upper receiver. If after checking everything else that could cause an accuracy problem, somehow its the wobble, then its time for a new rifle.
Ghosts of Rifles Past Not something you mentioned, but I did. Part of the AR-15s(and many other service weapons) bad reputation comes from its earlier incarnations, rounds used with at the time etc. The original AR-15/M16 was pretty different from the ones we know today, I honestly don't know all the differences firsthand, cause I've never got my hands on an old one, be here goes.
"The original AR-15 did not have a forward assist mechanism" supposedly. The story goes that the Air Force or somebody required the addition of the forward assist we all know today before adoption. Funny thing is, the rifle already had a forward assist. Ever wonder what the cut on the right side of the bolt carrier group is for?(the one with the two holes, which by the way are meant to vent impingement gases out of the carrier) It is the original forward assist, you simply had to put minor forward pressure on the inside face of the cut to seat the bolt. The weapons design is such that if the round didn't chamber on buffer/return spring tension or your finger push then something was wrong, either with the rifle or more likely the round, and slamming on the "new" forward assist might get things working, or might make the problem worse.
The original lower receiver was not as sturdy as the new lowers. The new lowers have reinforcements built into the design, the ridge on the right side mag well at the top, that splits and surrounds the mag release? Yeah, reinforcement points. The original M16's had slick sided receivers, I think they were actually a little thicker too, which you would think means stronger, but ridging metal is actually a very common method of strengthening without adding ridiculous mass.
I've heard the original rounds used were not only very dirty, but also not very powerful, I don't know as much about ammo in terms of powder though so take that with a grain of salt. Also the magazines used to supply the AR platform with ammo have only gotten better designed as time has gone by, and as previously stated some of the new mags coming out are amazing.
I've also heard the original M16's had a different rate of twist for the rifling in the barrel than modern ones, which led the old ones to loose accuracy with the light 5.56 round at range.
A big issue a lot of people had, and continue to have, with the AR is the choice of caliber. Everyone knows the US went from 7.62x51mm to the 5.56x45mm NATO. A lot say it was political, who knows. Considering the F2000 also blasts 5.56 this probably isn't such and issue for you, but it as a point where the the AR gets a lot of hate. So lets quell so of that shall we?
Yes, the 7.62x51 goes farther, faster, and is heavier, so it's ballistics profile is superior. Thing is, 7.62x51 is heavy, high recoil, and a decent bit more expensive than 5.56. 5.56 has the advantage of carrying almost twice as many rounds at the same weight, in a smaller space, so that's not only more rounds in a mag, on a soldier, it's more rounds in the squad, platoon, on the truck, in the ammo drop, etc. It's lower recoil, so less "manly"(sarcasm) shooters can not only manage recoil better, it gets back on target quicker. it's obviously cheaper, and we all know governments like that.
Terminal ballistics, I.E. what happens when the bullet hits the target. When I went through my police firearms instructor course, not too much study had been done on this, compared to other sciences. Most is done in ballistics gel, which is an approximate for flesh, but its not exact, and not a lot of people are volunteering to get shot under scientific circumstances. Anyways, it was still my favorite part and what we learned about the 5.56 was surprising. We'll start with the 7.62 though. I blows through fast and hard, leaves a big hole, and probably exits the back side, maybe from a bigger hole. That's great for it, its a great killing round, if you hit body. Oh it'll still mess up a limb, but the bullet is heavy and well put together, so it typically chugs right through without transferring a lot of energy to target.
Everyone has heard the 5.56 tumbles, I.E. it enters the target and wildly bounces around randomly, supposedly you can get hit in the leg and it exit the opposite shoulder, whatever. Again, this does happen, its been documented, but not a lot of people have gotten shot under controlled scientific study, so lets just say results may vary. It's supposed to be a round with high "wounding potential", cause supposedly you can take 3 soldiers(average 2 guys to carry the wounded guy) out instead of just killing one. I call crap on the 3 guys if wounded part, current Army tactics train if you are under fire and some gets hit, you encourage them to get to cover, tourniquet themselves if they can, and YOU SHOT BACK until there isn't a treat anymore. This is such common sense to me I imagine other branches, military and even the bad guys are relatively on the same page, can't help anyone if you're dead too.
So so far it comes to 7.62 "punch hole through" or 5.56 "maybe bounce around a bit". I'll sum it up like this, It doesn't really matter the size of bullet that entered your body, if it's in there, it's not suppose to be there, side effects may include; burning sensation, bleeding, decreased motor function, shock, hypovolemia(extreme loss of blood), collapsed lung/other airway damage, paralysis, and death. Bullets are bullets, they only work if you put them in the enemy, if you can carry more, cheaper, with less recoil, go for it.
After that said I will add one thing about the 5.56, where it really shines. During my Instructor training we reviewed close range ballistics gel tests of the 5.56 from certain barrel lengths. You know what they found at close engagement ranges? Imagine if you will the 5.56 is like a super speed boat you see on TV, racing across the water at near impossible speeds, you've ever seen the videos where the boat tries to be a plane? Crashes back to the water and comes unraveled? This is what they found the military issued 5.56 does at close range in ballistics gel, no more silly tumbling, the change of medium(from air to gel/"flesh") the round explodes, leaving typically around a fist sized hole.
The 5.56x45mm is a dominating defensive round, but considering you didn't change caliber's you probably already liked it, I'm just trying to point to others why it giving the AR15 a bad rap is undeserved.
TL:DR (Holy shit that's a lot of text, it just kinda flowed)
-Dirty: Improper cleaning, lube and long term maintenance
-Jams: Improper cleaning, lube and long term maintenance, poor mags, poor ammo
-Not a Bullpup: Well yeah, but both have their pros and cons. Apples to Oranges, both require continual training and practice to operate properly.
-Buttstock compartment: One variety/line of the platform, poor method to judge the line, plenty of affordable, easy to replace aftermarkets and options.
-Wobble/Tightness: Improper cleaning and long term maintenance, affects more than just receiver wobble, should not happen on a new/good rifle.
-Ghosts of Rifles Past: My own category, AR pattern gets a lot of guff still from problems of the past, it's not the greatest, but it has evolved and wouldn't still be in use with so many militarys, agency's and people if it didn't work.
I hope I've helped dispel some of the rumors and whatnot surrounding the AR15, its not a bad design, it has evolved, military ones get treated like dog s***, so take that into consideration when you hear so many people say it's bad, a majority of the user base is military/prior, but the military's rifles usually aren't the best examples of the species.
If anyone wants more info on anything I'm happy to help. (Did not expect this to turn into an essay, it just flowed from me(pretty surprised myself).