Sturgeon

This ain't a part of the 10%, folks. Cris Murray, former AMU gunsmith and one of the designers of the 6.8 SPC, rants about the 7mm caliber and his 7x46mm UIAC. 

One of the most amusing sections:
 

 

With their 7mm Mausers, the Spaniards shot the crap out of us in Cuba. If it hadn’t been for a few 5th Army Gatling guns and artillery that just happened to be brought along, things may not have gone as well for the Rough Riders as portrayed in the movies.  The British met the same 7mm Mausers in Africa in the hands of the Boers and were equally shocked by it as we Americans were.      There are those people who love to propose their pet calibers or cartridges they designed for match shooting or hunting: Most of these people have probably never been in a gun fight.  And all those people who suggest one of those accurate Scandinavian calibers apparently hasn’t read Louis LaGarde’s book, Gunshot Injuries (ISBN 0-935856-12-9) and found out why the Japanese quickly dropped the 6.5mm caliber after fighting the Russians in 1905 even though they basically win that war.  Actually any country that had a 6.5mm or smaller caliber service rifle quickly ditched it for something of larger caliber immediately after any fight they got into.        People with their 6 mm and 6.5 mm parlor cartridges don’t want anyone to know that the Russian “Unified Cartridge” program in the 1970s tried these calibers to replace the M43 (7.62x39 mm) and M91 (7.62x54R) with one cartridge, this program produced no useable cartridge.  Knights Armament want us to adopt a 6x35mm and SSK is touting their 6x45UMC;  the 6x45mm wildcat (necked up .223 case) has been around for 50 years, it is a weak pathetic cartridge so how is the 6x35mm (.221 Fireball necked up) any better. 

This guy is a demagogue nearly on the level with Sparky. There are almost as many provably false statements as there are sentences.

I've talked before, in other arenas, about how flawed the design of the 6.8 SPC is. I'd wondered for a long time why someone would design a modern rifle round like that. I guess I know, now.

Now I really want to see Cris Murray start a fight with Anthony Williams for favoring the "inferior Scandinavian 6.5mm".



 

Shuttle takes a lot of criticism, and according to my most recent estimates, approximately 52.4% of it - globally - comes from me, so pay attention. I'm about to praise it.

If you pay attention to spaceflight, you'll find that there's a couple of reasons to why we don't have colonies on other planets yet. One reason is that spaceflight isn't cheap. The other reason is that spaceflight isn't cheap because it isn't safe.

Alright, so why isn't spaceflight cheap? Well, imagine building a wonderful, awesome, complex thing, with lots of fiddly moving bits, and then you send it off to do what it does, and it explodes and is destroyed. You'd be pretty bummed, right? Rockets are designed to do that every single time they fly. That big Saturn V rocket that took us to the Moon, it didn't come back. The only thing that did come back was that little thing at the top that looked like Madonna's tit, and none of those ever flew again, nor could they. But some rockets do come back, like Space Shuttle. Those require a huge number of man-hours to refurbish and bring back to flying condition, and sometimes, despite the best efforts of those folks, they break up over Texas anyway.

Which brings me to my next point: spaceflight isn't cheap because it isn't safe. You know how awful paying insurance on your car is? Well, imagine paying insurance on a controlled explosion designed to throw something eight times faster than a rifle bullet. Even if it's not carrying dudes, that's probably not cheap. So spaceflight needs to become safer and surer, so the insurance premiums come down. It might help if we didn't let grandma drive the rocket; she's really too old to have a license.

So we need a rocket that's safe and reusable, ideally. That's where the Shuttle comes in.

Shuttle was neither safe, nor the kind of cheaply reusable we need, but it wasn't expendable, either. Shuttle had a lot of problems, but one thing it did genuinely contribute is experience with reusable systems. There are reusable hydrolox engines now that, without Shuttle, may never have existed. The Orbiter (that's the plane-looking bit) itself wasn't a dead end, either; the USAF's X-37B is currently flying, gaining us even more experience with reusable systems.

There's a very old metaphor, that what we can do now is only because we stand on the shoulders of giants. This conveys the value of experience, of building on previous accomplishments to achieve something great. Brilliant minds and ideas, foolproof engineering (no such thing! snorts my old boss), and eureka! moments dominate our minds because they are the sexiest part of progress, but more valuable than all of those, is having the experience, the shoulder of the giant to stand on to go somewhere new.

Shuttle, for all its faults, gave us an absolutely priceless body of experience in reusability (130 flights! That means a plurality of human flights into space have been on a reusable vehicle). Ultimately, it will be reusability and safety that open the door to space and let us explore the stars. Some have suggested it would have been better to not do Shuttle and instead do Apollo derived vehicles - there may be merit to this, but it must not be underestimated how important Shuttle has been in improving our understanding of reusability.

Now, how do we do reusability? Well, here's an email I sent to my father exploring an idea about that:
 

 

 

I've been thinking about space launch reusability, and how to accomplish it - most importantly with a low expenditure of man-hours.

One idea that came to mind is, is there a possibility that engineers are trying too hard to improve the efficiency of launchers by shaving weight everywhere and anywhere possible, instead of trying to improve the durability of components so that they can be reused?

I don't have a good appraisal of this situation, but modern launch vehicles are very efficient in terms of their construction. It seems almost a tautology to me that, if reusability is hard because it's expensive (e.g., every reused component must be inspected before reflight - I think the ideal is that this will eventually not be the case, right?), then launchers should be made more durable and less efficient.

Lord knows we have good launchers - take Shuttle as an example. If you decided, hey, we're going to make Shuttle Mk. II, and it's exactly like Shuttle Mk. I, except that it is strong as snot (say - replace or augment the heat tiles with protective shielding or a material that's thermally resistant and also doesn't fail when hit by foam) and can only lob 15 tonnes into orbit.

Of course no one would do that. But maybe they would if it were Falcon 9-esque, but with a reduced payload? If that really did pay off, wouldn't your flight rate go way up, and wouldn't your cost/kg go way down? At that point, who cares how inefficient the launcher is?

And as I said to him,

Alright, your turn. Tell me everything that's wrong with what I just said.

Ah, I see what you mean. So something like X-37C.

Is SLS not the answer you were looking for?

SLS, not STS, mate.

I'm currently working on making SLS-alikes.

All true; I read your book.

Of course, the bigger you get, the greater you have to risk using more engines in the first place. Unless you take to developing truly enormous engines, which, while safer, does cut into your development time. There's also no guarantee the larger engines will work.

So I think LOR really was the way to go.

Direct ascent seems like asking for trouble, to me.

Rockets get more problematic damn near exponentially as they get bigger. It's a pretty big miracle that Apollo had as few problems as it did (and it effectively killed six people), to do something even bigger even earlier sounds like a megacatastrophe waiting to happen.

Hell, just look at what a disaster the N-1 was.

Alright, so what's using them for the right stuff?

There was a board game very much like that which I played as a kid. It was sort of like an awesome cross between Monopoly and Risk, and you assembled a rocket and went to the Moon with it.

Erm, I think you made a mistake in that calculation - 60000 psi over that radius comes out around 300N, not 3N

http://www.wolframalpha.com/input/?i=60000psi+*+%281mm%2F2%29^2+*+pi

That's pretty significant for such a thin sheet of brass. You do have a good point about the bolt keeping the rest of it in - I'd forgotten it was so close around the firing pin. As for the pressure release, it sounds odd to me - the path from the propellant to the primer is quite open, so you ought to end up with a substantial amount of gas blowing past the primer if it is going to equalise the pressure. Also, with that gas cancelling out the chamber pressure, you shouldn't expect to see machining marks on the primer surface

Oops. I think somewhere along the lines I converted mm to cm wrong.

Anyway, yes the bolt is right there keeping it in. Both of you, stop trying to prove reality wrong! 

We're trying to figure out why the primer doesn't back out of the case under pressure.

 

At peak pressure there's metric fuckloads of force on the primer, the same primer which was installed from the back and is basically only press-fit into the pocket.  The firing pin doesn't seem massive enough to stop it.

Oh, silly, you know why. 1. There's fuckloads of pressure against the sidewalls of the primer causing it to grip the primer pocket. 2. The bolt is there stopping it.

If you look at cases "before and after", you can see that the primer actually does expand. Not only does it get more "square" around the edges, it also protrudes further in a fired case compared to an unfired one. In fact, most of the time you can actually just make out machining marks imprinted on the face of a fired primer, left over from when it was trying its damnedest to become one with the bolt fact. I'm looking at a fired .30-06 case right now that exhibits these markings.

Bay Area, really.

Primers don't have very much explosive in them. I've popped new unseated primers before; an M80 creates a much, much bigger explosion (cue videos made by dumb kids) The primer cup itself is enough to contain the primer's explosion.. The pressure produced by the powder charge is successfully contained by the bolt resting against the primer.

Why don't they burst? They do; popped primers are one of the major signs of overpressure (though if you're popping primers, you need to back way the hell off, as even the lower end of unsafe pressures usually doesn't pop primers). Read this for a little more info.

Why do they retain the firing pin impression? Good question, I'm not sure, but can think of a few possible reasons. One is that on the other side of the primer cup is the anvil, which may prevent so much pressure from pushing back against the indentation left by the firing pin. Another is that primers are usually pretty hard, and they have a yield strength above the pressure being produced. Keep in mind, the pressure being produced is high, but the area's very low, so the force involve is also probably low (assuming 60,000 PSI and 1mm diameter, that means 3.27 Newtons force are being exerted on the primer. This is equivalent to the force of gravity on something that weighs 2.4 ounces). A third theory is that there's enough pressure escaping around the primer to equalize the pressure on it. I think this is probably likely.

In which Tony Williams declares the caliber debate "over", while mis-representing a PEO Soldier report.

I agree with Ensign. WarThunder is inferior because it's a worse game. It sort of looks prettier, but the gap is closing there, too.

Fair point. I did want the aerospace nerds to see it, though, and I was very tired last night.

Save yourself the $10 (16.50 IMAX dollars). Don't go see it if you like space exploration.

My critique of Emeric's paper, for those interested.

By far the best document yet written in favor of the GPC concept. I guarantee you'll learn something reading it, too.

Note: While hosted on his site, it was written by a Frenchman - Emeric Daniau - participating in France's current small arms research program, not Tony Williams.

The prominent rear-sight block and lack of muzzle beyond the front sight block says StG-44 to me.

Great posting, Unstart.

Our first week here at SH is done. Honestly, this has been a much stronger start than I expected, and I thank everyone who's posted for helping.

There's a lot of good content here already; I can hardly think of a thread that doesn't contribute something to the making of SH into the research center I had in mind when I started it.

So thanks to everyone, and let's keep the momentum up. For now, if you have a question, ask it on the forum! Have a friend that you think has the archive savvy, inquisitive nature, and ritual-sacrifice-obsidian-dagger-blade-sharp wit that would make them a good fit for SH? Invite them! (For now, I ask members to invite only one person a piece; myself and collimatrix are currently working to expand the membership of SH by adding more people we think would be assets to the forum.)

Carry on, gentlemen!

The Apollo Program is in my opinion the greatest achievement of mankind, so far. I am biased of course, but this isn't for knowing nothing about the manned spaceflight effort of both the United States and Soviet Union during the '60s. I wouldn't consider myself an expert in the remotest sense, but I am much more familiar with the details than the average joe.

So I say this as someone who most decidedly believes that Apollo was a demonstration of excellence of the highest order: Should we have done it?

I encapsulate in this question a couple of distinct ones. First, given the inexperience of the U.S. space initiative, it seems to me that Apollo was positively charmed given that it only suffered the problems it did. The breakneck speed at which the US raced for the finish line is... Well, in retrospect a bit concerning. Consider a few facts that help highlight how absolutely primitive from a development sense Apollo really was: Neil Armstrong was one of nine astronauts selected in only the second class of NASA astronauts ever, following the original "Magnificent Seven". Further, the Saturn V rocket was the first purpose-designed manned US orbital launch vehicle ever to fly (you might count the Saturn IB, but consider that its first stage is literally a bunch of short-range ballistic missiles strapped together atop adapted V-2 rocket engines, and that the rest of it is the third stage up of a Saturn V). This makes sense, considering the Apollo program was begun before the US had even made its first manned suborbital flight.

Taken into account, these facts don't blemish the accomplishments of Apollo at all; in fact, to me they make Man's first footsteps on the moon all the more glorious. We challenged the Soviets to the greatest race in history from a sitting start, and won by (hundreds of thousands of) miles. But that's not the point; Apollo really was just one more baby step on the road to having a full-fledged, mature space program, that's why I ask...

Second, did Apollo set a dangerous tone for US manned spaceflight from that point on? Consider the dangerous Space Shuttle, which I won't go so far as to call "ill-conceived", but which clearly left a lot to be desired in the safety and management departments, was already in the planning stages before even the landing of the Eagle in the Sea of Tranquility. If Apollo was the product of the US space program in its very infancy, what was STS? The triumphant second lap of an unbeatable runner, or a dangerous gamble against luck?

I don't really know the answer to these questions. Spaceflight is dangerous, and unfortunately in an operation as complex and risky as this, some people may very well die. I don't hold responsible the desire to explore our cosmos for the deaths of astronauts or cosmonauts in any incident; but when a holistic view of things is taken, it's remarkable just how much is done with how little was known. And with that, I can't help but wonder how things might have been different.

Discuss.

Yeah. When he starts out by extolling the 6.5 Arisaka right off the bat - I own one and actually LIKE the action - he loses a lot of credibility.

I like the current "golf bag" approach. But I'm a Mark 1 civilian and am used to having one gun that does - more or less - one job.

It's a fine cartridge in my opinion, but he doesn't really account for the relevant internal ballistics of the round. He assumes there's this big gulf in performance for a given peak pressure that's possible now that wasn't then, and that's really not true.