T___A

Now that Weaponsman has linked the forum, I guess it's time to post actual content.  No more dumb one-liners or jokes about the Turkish government's policy towards Kurds or Sherman burning down Atlanta.  For at least five posts.  I think that's all I can manage.
 
The internet has been a mixed blessing for gun nuts.  On the one hand, it allowed for much freer exchange of information that was previously exclusive to a few experts.  The notorious mil-spec chart (no longer up to date) that circulated around ar15.com years ago is probably a big part of the reason that AR-15 manufacturers stepped up their game and started turning out generally excellent products.
 
On the other hand, the internet has been an excellent vector for the spread of nonsense.  In my experience, relatively little of the misinformation is maliciously spread; it's mostly the result of people not knowing what the hell they are talking about.  In particular, a great deal of nonsense would be ignored if people could just remember high school physics.
 
A lot of mystical, physics-defying rubbish is said about weapons reliability in particular.  Reading nothing but internet fora circa the late 2000s, one could easily come away with the impression that the AR-15 is uniquely unreliable thanks to the direct impingement action.  This is despite the fact that coating aluminum or steel in a thin layer of carbon powder would actually reduce its coefficient of friction.
 
Actually, the dynamics of automatic weapons are not difficult to understand.  An often overlooked metric in the reliability of gas-operated automatic weapons is the mass ratio between the bolt and the bolt carrier.  I first became aware of the importance of this ratio when reading a US Army manual on small arms design at Forgotten Weapons.
 
Just to be clear, this ratio is only important in the way I'm describing in gas-operated, some recoil-operated and inertia-operated weapons.  The dynamics for retarded blowback weapons, like the H&K G3, are quite different.
 

 
In a gas-operated weapon, there is a bolt that is locked rigidly either to the barrel or to the receiver at the moment of firing.  This contains the pressure of the cartridge firing (which is alarmingly high).  The projectile is pushed down the bore.  As soon as it passes the gas port, some of the gas begins pushing the bolt carrier to the rear.
 
The work done on the bolt carrier by the propellant gas from the gas port is the only energy that the bolt carrier will have to complete the cycle of operations.  This means that the total work required to:
 
unlock the bolt
pick up the bolt
extract the spent case
cock the hammer
compress the return spring
operate the belt mechanism (if it's belt fed)
 
cannot exceed the amount of energy that is initially fed to the bolt carrier.  Ideally, the bolt carrier will have some excess reserve of energy so that it can complete the cycle of operations even if the gas port is slightly clogged, the ammunition is slightly under-loaded, or the receiver is dirty (et cetera).  However, if the bolt carrier has too great a reserve of kinetic energy, it will still be travelling rapidly when it reaches the end of its travel, and then it will violently jerk to a halt or possibly even bounce off of the rear of the receiver.  This increases wear on the weapon, and in a shoulder fired weapon can cause the sights to jerk off target.
 
There are two ways to increase the energy capacity of the bolt carrier; make it go faster (in gas-operated weapons, this is done by the simple expedient of enlarging the gas port), or make it heavier.  There are practical limits on how fast the bolt carrier can reciprocate; according to Brassey's, a good rule of thumb is 15 m/s is the maximum practical velocity of the bolt carrier.  Above this velocity things start to break.  Cases can be torn apart instead of cleanly extracted from the firing chamber (the Soviet SHKAS fast-firing aircraft machine gun required special high-quality ammunition with extra-strong cartridge cases), springs lose their strength in fewer cycles, and the lifespan of the moving parts is reduced due to increased fatigue.  Making the bolt carrier heavier also has practical limitations; the weapon becomes heavier not just from the heavier bolt carrier, but also from the larger receiver needed to enclose it.  In shoulder-fired weapons the sights will be thrown off target by the porpoising motion of the reciprocating center of mass.
 
The act of picking up the bolt after it is unlocked is of particular interest, because it can absorb a great deal of the energy from the bolt carrier.  The bolt is picked up and accelerated by the bolt carrier, after which they are stationary relative to each other.  This means that there is an inelastic collision between the bolt carrier and the bolt, and in an inelastic collision kinetic energy is not conserved even though momentum is.
 
The initial kinetic energy of the carrier is 1/2MV^2.  The initial and final momentum of the system will be the velocity of all moving mass times that mass.  This works out to a reduction in kinetic energy after the pickup of the bolt.  For instance, if the bolt and bolt carrier have equal mass, after bolt pickup the velocity of the bolt carrier group will be half of what it was before and the mass double what it was before.  That works out to half the kinetic energy of the bolt before pickup.  Generally the equation for the remaining energy after bolt pickup will be:
 
E2=E1*(1+1/R)-1
 
Where E2 is the bolt carrier group kinetic energy after bolt pickup, E1 is the bolt carrier kinetic energy before pickup, and R is the ratio of mass between the bolt carrier and the bolt.
 
If anyone is terribly curious I can show the derivation of this.
 
According to the US Army Ordnance small arms design manual hosted at Forgotten Weapons, designers should shoot for a mass ratio of 3 or better, which would translate to 75% energy retention after bolt pickup.  More is better, but there are strong diminishing returns here; a weapon with a mass ratio of 2 will have 66% remaining kinetic energy after bolt pickup, but a design with a mass ratio of 4 will have 80% conservation.  As the mass ratio gets larger and larger, the percentage of bolt carrier kinetic energy after bolt pickup will approach 100% asymptotically.
 
Again, to keep designs lightweight, the ideal way to achieve this would be to make the bolt as light as possible.  However, in a locked breech weapon in 5.56 NATO, the bolt has to withstand peak chamber forces of 22.7 KN (or 5,100 lbs if you're using haram infidel non-SI units).  It therefore has to be fairly robustly constructed, and making a lightweight bolt that is still safe over the operating life of the weapon is not an easy engineering task.
 
When determining the ratio for actual weapons, it's important to define exactly what masses are involved.  What we are looking at is the ratio of the moving mass that is accelerated by gas that will have kinetic energy available to accelerate the stationary mass.  Take a look at this slow-motion video of an FAL firing:


 
The piston follows the bolt carrier back far enough that its energy is available for bolt pickup, even though it's a separate piece from the carrier and doesn't translate through the entire distance that the bolt carrier does during cycling.  So, for the purposes of determining bolt carrier to bolt mass ratio, the piston of the FAL counts as bolt carrier mass.
 
In an AR-15, the firing pin rides in the bolt carrier, is pressed forward against the bolt carrier during the initial acceleration, and therefore counts towards the mass of the bolt carrier group.  However, the buffer is not rigidly attached to the bolt carrier, so its kinetic energy cannot contribute towards bolt pickup.  Therefore it does not get counted.
 
Obviously any extractors, cam pins, and miscellaneous other parts get counted toward the part they ride with.  Strictly speaking some portion of the mass of the return spring should be counted (and Chinn's excellent The Machine Gun has equations for calculating the impact of spring mass on reciprocating parts dynamics), but I was too lazy to include this because it's really, really small.
 
So, let's see how well actual designs do:
 
 
Semi-auto TAR-21
 
carrier group mass:   .623 kg   bolt mass:   .055 kg   Carrier to bolt mass ratio:  ~10:1   Notes:  It is impossible to remove the return spring from the bolt carrier of the semi-auto TAR-21 for some arcane reason, so I had to guesstimate on this one.  However, whatever the exact number, the TAR-21 has an exceptionally high bolt carrier to bolt mass ratio, and that is one of the (few) outstanding features of the design.  Using a stationary cam pin that is located in the bolt carrier that acts upon stationary cam grooves in the bolt is one way that the design improves the mass ratio, and this unusual feature is worth emulating in other designs.  Sadly, the design as a whole is not as elegant and mass-efficient as the bolt carrier group is.   SIG-551A1   carrier group mass:   .505 kg   bolt mass:   .093 kg   Carrier to bolt mass ratio:   4.4   Notes:  Disappointingly low, but still above the magic 3:1 figure.  The SIG rifles show one of the advantages of a reciprocating charging handle; the mass of the charging handle is adding to the kinetic energy of the bolt carrier, rather than being deadweight.  The bolt on the SIG rifles is fairly massive, in part because the firing pin is located in the bolt rather than the bolt carrier.

7.62x39mm AK
 
carrier group mass:   .505 kg   Bolt mass:   .080 kg   Carrier to bolt mass ratio:   5.3   Notes:  The charging handle and piston are one piece with the bolt carrier on an AK, which helps improve the mass ratio.  The bolt is fairly massive, in part because the firing pin is located in the bolt.   Semi-Auto SCAR-H   carrier group mass:   .713 kg   Bolt mass   .066 kg   carrier to bolt mass ratio:   9.8   Notes:  In the AR-18 derived bolt carrier designs the cam pin is rigidly attached to the bolt, and therefore increases its mass.  Also, the bolt must be sturdy enough to withstand the stress of 7.62 NATO ammunition.  Despite this, the SCAR-H manages a monstrous 9.8 mass ratio in a rifle that's still reasonably light for an automatic 7.62 NATO weapon.

T-64 does not approve

Pedersen was such a unique genius that he was able to take the limitations Browning imposed on pistol design through his patents and turn them into opportunities. For example, Browning held the patent on attaching grip panels via screw. Pedersen took this as a challenge and came up with a reusable rivet system that is arguably better and certainly better looking. As another example, Browning's patent on the tilting barrel mechanism caused Pedersen to come up with hesitation locking - oh, that's right, for those folks who don't know, the above pistol, the Remington 51, operates via a completely unique mechanism. Not only is it totally unique to Pedersen so far as I know, it's arguably a better mechanism for pistols of that type than any other, provided the manufacturer can hold the tolerances they need to.

If I keep going about how unique and awesome the Remington 51 is, I wouldn't stop. Suffice it to say, Browning wasn't speaking lightly when he called Pedersen "the greatest firearms designer alive, possibly of all time", and he was right.

A Taurus 1911 clone in .50 GI for all of your needs.
 

The boat I want added to WoWS the most:

Mr. Plinkett needs YOU to watch for his CAT until he is done with his next REVIEW.
 
This is our RLM thread, which we should have, because reasons. If you don't know who RLM is, that don't bother to look - just watch. 
http://redlettermedia.com/
 

Just random picture of Rich Evans.
 
I will start it by posting their latest (and maybe one of the best) "Best of the Worst: Wheel of the Worst" episode. 

 
So good!

Demonstrate how effective of a rifle it is while losing at least 2 colonies in the process.
 
Ok go.

This has all been translated from my forum posts in Russian and from war game Reddit which is where it was originally posted and then moved to other forums and back here.
I dont care if you cant read it well
Overview: Romanian Socialist Republic’s Army is quite different from other NSWP armies and although have a lot of common equipment, there are important differences in some approaches.

Because of Ceausescu's obsession to produce everything in country and lack of trust from Soviets to sell better weaponry, Romanian Army was obliged to develop its own models and inspire even from Western army or collaborate with China. Economically it was bad and Ceausescu simply couldn't grasp the economics of the fact that you can't produce 100% of everything in country without bankrupting yourself.

Remember that TR-580 production started in 1977, it didn't matter that the T-72 was superior, as long as Rumnia could produce a tank - any tank - in country. Sure, later TR-85 was better and some Chinese and Western help was used but was still a medium tank rather than an MBT.

So, there was less money for acquisition from abroad, resulting in the acquisition of small numbers of advanced weaponry, and even those few were not top of the line. The T-72s Romanian Army got were the early T-72 Ural1, MiG-23s were MF version when others in the Warsaw Pact were buying MLs. Very few AT-4/5 were acquired because Rumania produced the antiquated Maliutka which was eventually upgraded with Western help. Upgraded local variants were not bad but not top of the line of course.

They stubbornedly pursued the license production of the useless RS-2US/A-90 and AA-2 R-3S/A-91 air to air missiles of 1950 and 1960 vintage MiG-21s - the backbone of the air force - while WP neighbours equipped theirs with R-13M, R-60 and R-3R. Some studies were made to design better missiles and local copies were constantly improved but in the end it was older equipment. And examples could go on. Later, these missiles were upgraded so somehow the gap was closed.

After 1990 Romania was bankrupt, and only little money was available for upgrades in the 90's but some of those upgrades proved very successful as MIG-21, still in service, with DASH helmet and Israeli avionics. There were not enough T-72s to upgrade, and not enough money to build TR-125s which was a fine tank for its time. Just like it was the case with the MiG-21 versus MiG-29 upgrade, former was dropped due to low number of planes and because maintenance should have been made in Russia. Many products were presented only at first military exposition after 1989 events which took place in 1999. But this is because at that time was the first public exhibition and were researched even from early 80s; it was a huge secrecy developed by weapons producers which was the norm during Ceausescu’s regime. Many others were dropped in late 80s/early 90s due to lack of finance and very few info are still available. Western helos were available (licensed SA-330, Alouette) and some very interesting protos (IAR – 317, probably only dedicated attack helo designed at that time by a WP country except USSR); also, collaboration of Romania with China in military research could give a deck with a selection of Soviet style tanks (T-55 with upgrades, basic T-72) and Romanian tanks with Chinese modern FCS, stabilizer and other stuff (TR-85M, TR-125).

Object 770 with smoothbore 140mm M-65GL:

 
 
Also the Object 277, 278, 279, 770 all had -5 degrees of depression checkmate T110 thread.

Object 770 with smoothbore 140mm M-65GL:

 
 
Also the Object 277, 278, 279, 770 all had -5 degrees of depression checkmate T110 thread.

Pinnacle of firearms tech:
 

Taurus is definitely a not a bad company.

OK, maybe this is unfair to Robert Zubrin, but here's my drunken, late-night ranting on WHY HAVEN'T WE GONE TO MARS? WAAAAAH.

Ready for the short answer? OK: It takes a fucking long time to get to Mars.

(hopefully not too) Long answer:

Many people thought the Mars landings would be the natural follow-on to the epic Lunar landings of the late '60s and early '70s, and they weren't necessarily wrong. I still feel the Mars landings are a natural follow on, but there are some reasons besides shinking budgets, a loss of romance, and ennui that I feel are worth examining. I am not an expert, and I welcome anyone who is stepping in and telling my I am wrong, but I will nonetheless do my best to get this stuff right.
 
So, it might feel like a Mars mission would be just like a Moon mission, but with a bigger rocket and maybe a habitat and stuff, right? Well, that's accurate, but it's not everything. I don't claim to know everything about a Mars mission, but here's some stuff to think about. 

First, we have to understand that a hypothetical Mars mission is not like a hypothetical Lunar mission, and the most important differences have nothing to do with Mars itself! A trip to the Moon takes about three days. Coincidentally, a human can survive about that long with no resources whatsoever except air. This means that a Lunar mission needs to take along on-board supplies lasting for six days, and oxygen for six, and that's enough for the mission plus contingency. Now, the important part here is that the Lunar mission doesn't need to develop any living techniques to complete its mission. Simply, they can easily bring along what they need to survive.
 
For a Mars mission, it's several orders of magnitude more complicated. The mission takes a minimum of 130 days one way, if you have awesome high speed rockets. More realistically, 260 days is your one-way trip. That's close to 9 months of travel there, then 9 months back. Asking "how much weight of supplies would you need to supply one human on that trip?" is so complex as to be almost meaningless. Let's look at just water. A human needs several quarts of water per day to survive, just to drink. So for 260 days, one person would need about a metric ton and a half of water. That's for hydration alone, and more would probably be needed. It would be difficult to calculate exactly the delta-v needed to move a steadily-venting metric ton point five of water to Mars and back, but this alone represents a problem.

Can you do a Mars mission via supply alone? Clearly you can theoretically-speaking, but consider that the weight of daily supplies needed for a Mars mission would be 87 times that needed for a Moon mission, and then recall the size of the Saturn V rocket that took us to the Moon. Then add in the weight of ancillary supplies like medicine, etc, that would be needed because a Mars mission can't just abort. Being on a spaceship halfway to Mars is the remotest man has ever been by well over three orders of magnitude; a doctor in Antarctica by comparison has instantly available help. 
 
This is all to say a Mars mission has to be a self-sustaining ecosystem, barring mind-boggling available delta-v and awesomely huge launch vehicles with which to launch a tremendous amount of supplies. One hundred and twenty man-months' worth of MREs and water doesn't seem like such a big deal until you see how big the rocket(s) needed to take it to Mars and back have to be.

So we've recharacterized the problem. Clearly, getting to Mars isn't so hard. We've visited it by proxy loads of times. But now we realize that those probe missions weren't NASA just dicking around, they were actually dramatically lower intensity than a supplied Mars mission. To bring humans to Mars, we need to replicate the human ecosystem, and stick it on top of a rocket, or more likely in pieces atop multiple rockets. Replicating the human ecosystem sounds straightforward... Until you actually try it. This is Biosphere 2 (Biosphere 1 is Earth, yes, I know, nerds ruin everything):


 
Biosphere 2 was one of the first major projects in trying to replicate Earth's ecosystem apart from itself. I am not going to say that we learned nothing from Biosphere 2, but in the context of preparing for a Mars mission, Biosphere 2 did not result in a viable system for space exploration, so far as I can tell. For a start, Biosphere 2 is much, much too large to launch atop a rocket!

It sounds like I'm getting down on Biosphere 2, but I actually respect the effort quite a bit. It just isn't the result we need to get to Mars by 1995. However, there is another human habitation that has given us a much greater head-start towards a Mars mission than Biosphere 2:
 

 
Good ol' Alpha. I feel as though the public perception of ISS has been a little harder on it than it should be. A space station feels unglamorous. It doesn't feel daring, like stepping on the Moon was, and it doesn't feel dangerous or brave. ISS has gotten more popular in recent years, as its competition for the spotlight (particularly Shuttle) has faded, but it still never captured people's hearts like Apollo or even Shuttle did.

But really, ISS is kind of the Apollo 9 of the Mars effort. OK, that analogy doesn't go very far, but ISS is a crucial experiment - a long term one - in the process to going to Mars. We're putting people in space for very long periods of time, and seeing what exactly it is they need to survive up there. We now know exactly what technologies we need to perfect to supply and keep alive people during the twenty-month Mars mission, because we've already kept people alive in ISS for that and longer. And, we're making very significant strides:



To avoid getting into too much detail, and recognizing that I think I've made my point, I'll leave it there, adding one final thought. NASA is staffed by people who want to go to Mars. Every single person at NASA, from Charlie to the janitorial staff, probably hold as mankind's finest achievement the Apollo Moon landings, and they want to see that achievement topped by landing human beings on Mars. I would be willing to bet that NASA could get a direct order from Congress to in no way pursue a mission to Mars, and we would still make progress in deliberate, calculated, secret ways towards that goal. The perception (which I have been guilty of, too) that NASA is sitting on their ass and needs to get on with it, is probably less justified than we want to believe. Going to Mars will be hard, and there's no guarantee that we'll make it the first time. There are a lot of problems that need solved, a fuck ton of engineering to realize those solutions, and industrial quantities of bravery needed to execute them.

Putting people on Mars will be the greatest achievement in the history of mankind, until the next. Not because it is easy.
 

Rekt
 

"Oh no, Lincoln suspended habeas corpus in the exact circumstances the constitution provided for. What a monster!"

Taurus is definitely a not a bad company.

Links to Jezebel...

it all makes sense now
 
 
also, i never cared for the C-96
 
I dont care how much pussy it gets you or that its Han Solo's gun
 
The thing is more front heavy than my third wife and a stripper clip pistol is retarded for obvious reasons 

This thread is now the third google result for "Blacktaildefense," and fourth if you search "Blacktail defense."  Truly, my plan to harvest e-fame from lunatics with inflammatory forum postings is going well.  Soon, innocent people who just wanted to learn a thing or two about tanks will read my evil writ, and my plans can enter Phase Two.
 
This also means it's time to point out more of the knee-slapping idiocy in Blacktail defense's horrible, horrible youtube videos.
 
We'll start with one of his screeds on aircraft, just to show that, in addition to tanks, he doesn't know jack about any other military equipment either:
 

 

 
 
This is, in the Frankfurtian sense, bullshit.  It incorporates elements of truth and lies indiscriminately, because its author's purpose is indifferent to the truth.  The author's purpose is to impress you and tell a story, and bask in the adulation of the bamboozled.
 
The most obvious illustration of this insouciant attitude towards research is that there are several basic chronological errors.  The Carter Administration policy decision on the export of advanced weapons dates from March 1977, not February 1979 as the video repeatedly states, which means that any causal relationship with the Iranian Revolution (which did happen, or at least wrap up in February 1979) is clearly impossible.  He states that the Mirage 2000 was an earlier design than the F-16, despite the F-16 first flying four years earlier.  Finally, he states that the J79 turbojet was still in production in the United States at the time of the development of the F-16/79, when actually it ceased the same year that the F-16/79 project was initially announced.
 
There's also a puzzling lack of knowledge about basic airplane mechanics, for a video that purports to educate on the history and function of warplanes.  The Mirage 2000 is stated to lack "Dynamic Instability," which so far as I can tell is an actual technical term, but one that is used in chemistry, not aeronautics.  For the record, the instability of the F-16 and Mirage 2000 are completely qualitatively equivalent.  In both aircraft the center of lift in subsonic flight is in front of the center of gravity, a condition which will amplify any deviations from straight and level flight and requires the plane to essentially be flown by computers.  In fact, instability is just as essential to the design of the Mirage 2000 as it is to the design of the F-16, if not more, because the unstable relationship of the center of lift and center of gravity is what allowed Dassault to return to the tailless delta configuration after ditching it with the Mirage F1.  Instability mitigates many of the flaws of a pure delta-winged aircraft (such as poor takeoff and landing performance) while preserving all of its merits.  Without that breakthrough, Dassault would never have gone back.
 
There are two other errors that are telling enough to be worth mentioning (and a whole lot more that aren't worth mentioning).  The first is where Blacktail wonders why the TF30 wasn't used as a downgrade engine for the F-16; a question one would only ponder if they were unaware that:
 
1)  The TF30 had, by that point, developed a completely deserved reputation as an unreliable and dangerous piece of crap.
 
2)  The TF30 is physically wider than an F100 and thus will not fit in an unmodified F-16.
 
Also, Blacktail described the F-16's fly by wire system as "duplex."  This is a particularly telling error because it shows that Blacktail is just throwing around technobabble and does not understand what it means.  The F-16 is unstable in cruise flight and thus must by flown by computers.  But suppose the computer should bluescreen or something, wouldn't that mean the aircraft would depart controlled flight and smash into the ground?  Yes, yes, it would mean just that, if there were only a single computer flying the plane.  The F-16 uses parallel quadruple-redundant computers, and their output is cross-checked before being fed to the aircraft's control surfaces.  If a single computer goes tits up and starts spitting out nonsense, the cross-checking system can see that there are three signals agreeing with each other, and one that's disagreeing.  It knows to toss out the numbers from the lone dissenter, and the aircraft does not flutter out of control and smash into the ground.  In the extremely unlikely event that two computers go tits up simultaneously, there would be two channels returning random gibberish and two that still agreed with each other, so those two channels would be given priority and the plane would continue to fly.  The only way this system can fail is if three of the four computers crash simultaneously, which is unlikely enough that it need not be worried about.  A duplex, or doubly redundant system wouldn't help; in the event of failure the cross-checking system would have no way of knowing which channel was in error and which channel was still working properly.
 
Blacktail gets facts wrong because he's allergic to basic research.  However, there could be individual errors in a piece, and they still might not invalidate the greater thesis of the piece.  Near as I can tell, he has two points to make:
 
1)  The F-16/79 would not have helped prevent the proliferation of advanced technology because it was still packed full of it, downgrades to the engine and radar notwithstanding.
 
and
 
2)  The F-16/79 could easily have been upgraded to equivalent or better than the F-16A with parts from other countries.
 
Both points enormously overestimate how easy it is to design modern warplanes.  How does weapons compatibility in an export aircraft equal weapons proliferation?  How exactly are people supposed to reverse-engineer weapons from pylons that fit them?  Who, in 1979 would have been both interested in fly-by-wire systems and would also be capable of making them?  The Soviets might learn a thing or two by picking over an F-16, but only a thing or two.  By the late seventies they'd already been flying their own unstable, fly-by-wire prototype fighter for years (which would become, after extensive redesign, the SU-27).
 
The second point is dubious as well.  The Snecma M53 is at least physically capable of fitting into an F-16, but it's not a match for the F100.  Specific fuel consumption is dramatically inferior.  More saliently, putting a new engine in an existing fighter is a tricky bit of surgery.  To accommodate the F110, the F-16's air intake needed to be entirely reshaped to meet the engine's different air flow needs.  To accommodate the J79, the Kfir's air intakes needed to be redesigned and the entire aft fuselage redesigned in order to provide enough cooling for the new engine.  These are non-trivial operations, to say the least.
 
So, no, nothing to see here.  Blacktail doesn't understand aircraft either.

Finally the Iron Warriors T-72 Tank Command killer I've been waiting for.