Wednesday, January 28, 2009

On Rollers.

Or, an Exercise in Splitting Hairs

For some bizarre reason, this topic has been ricocheting around in my head all day, so here goes...

Several firearms, mostly designed in Der Vaterland, use rollers in their operation. While they serve the same function (locking of the bolt), there are two distinct designs that use locking rollers: roller-locking and roller-delayed blowback. The former is employed most notably in the MG42 and CZ52, while the latter is a trademark of Heckler & Koch.

Roller-locking is a form of short recoil operation. In these guns, the barrel moves a short distance (a quarter inch or so in the case of the CZ52), at which point the rollers are allowed to unlock the bolt. In this way, these guns operate much like modern autopistols using the Browning tilting barrel locking method. Since the start of the unlocking process is delayed by the barrel movement, chamber pressures have dropped considerably from peak by the time the bolt unlocks. The spent case can be extracted with little effort. (As an aside, the MG42 uses a muzzle booster to cycle the barrel more forcefully - a feature seen in many other recoil-operated machineguns, and about the only time any sane person would want a recoil enhancer.)

Roller-delayed blowback is another can of worms entirely. In delayed blowback arms, the blowback action begins immediately; however, the action retards the rearward movement of the bolt in some manner, so that the bullet has time to leave the barrel and chamber pressure can drop before extraction. In these guns, the cartridge case begins to move rearward immediately. Since the chamber is at peak pressure, this presents a problem. At rifle pressures, the case, being a thin sheet of brass, pushes out against the chamber, and refuses to budge. If extraction is attempted at this point, the case can be torn in half, which is a good way to muck up the operator's day.

To combat this, cases must be lubricated. In the Schwarzlose machinegun, the cartridge feedway included an oil pump for this purpose, as did the thoroughly screwy Breda model 30 light machinegun. (I'm starting to think that the Italian military refused to adopt an arm unless it met some minimum screwiness quotient. How any of Beretta's arms were approved remains something of a mystery.) John Pedersen developed a toggle-locked semiautomatic rifle for the competition eventually won by the Garand; for proper operation, the rounds were coated in beeswax (which, being a dry lubricant, had the distinct advantage of not pulling dirt into the action). This approach, according to Major General Julian S. Hatcher, worked better in practice than in theory.

The good folks at CETME (and later H&K) sidestepped the lubrication problem with a fluted chamber. When fired, these flutes 'float' the cartridge case on high-pressure gas, which allows it to begin the extraction process in one piece while still under pressure. This has proven quite reliable, but has the side effect of trashing the brass. If you're a military and have millions in OPM to buy fresh ammo with, this is a non-issue. If you're a civilian with a working man's ammo budget and a Dillon 550, this is a distinct problem.

H&K also made the P9 and P9S handguns with what is unhelpfully described both as 'roller locking' or 'delayed blowback,' often in the same sentence. As far as I can tell, the bolt face is a separate piece, and the rollers lock it to the fixed barrel; when the slide has retracted enough, the rollers can cam inwards to unlock the slide from the barrel. Almost reminds me of the 'shifted power stroke' used by Pedersen on the Remington 51 and M1917 pistols. Now I *really* want a P9 to fiddle with... (if anyone can enlighten me vis-a-vis the P9 operation, I'd much apprectiate it.)

Monday, January 26, 2009

On Controlled Feed and Shotguns.

Useless gun factoid #7,293,965: Winchester Model 97s use controlled round feed. The shell lifter slips the next shell neatly into the waiting arms of the dual extractors.

As an added bonus, the one I have (and I have no idea whatsoever if this is standard) has an overtravel stop on the trigger. Now that is attention to detail. That was the good ol' days, when men were men and skilled labor was cheaper than materials. And damn if it doesn't point like an extension of my arm.

The Winchester 97 is also used for one of the most unintuitive shooting methods known - the rapid single-loading (or 'tactical' if you prefer) style. Talk about design by rules fluke. Still damned impressive:

On Silver Linings.

Good news: A CZ52 will continue to fire with a machined aftermarket firing pin snapped in half.

Bad news: See above. I should probably buy these things in Costco packs.

Sunday, January 25, 2009

On To-do Lists.

I have a perfectly good Model 1897 Winchester, 30" with full choke, that I have yet to shoot.

I have a trap/skeet field within 15 minutes of my house.

Hmm.

Saturday, January 24, 2009

On Earworms.

Ever had a song pretty much permamently stuck in your head?

No, me neither.

On Randomness.

Strange thoughts come to me when I'm out for an evening walk. For instance, I wonder if anyone'd shoot an IPSC/IDPA stage based on the opening scene of Narc...

On Irony.

Why is it that the only language that the page on the "Just-world phenomenon" is Polish?

I mean, why not go whole-hog and do Hebrew as well?

Friday, January 23, 2009

Capsule Movie Reviews.

Elite Squad - It's City of God, from the cops' perspective, minus the hope. Unless you're this guy, you probably don't equate "high-speed, low-drag" with routine torture. The scenes illustrating pervasive police corruption are black, black tragicomedy. And the white-collar upper-class university kids don't evade a shanking either. Nonetheless, very well made. Also, only instance of cinematic dry-fire practice I've ever seen, which is worth something.

Brain Donors - It's everything good the Marx Brothers did crammed into 1 hr. 16 min. The same kind of spastic silliness of, say, Airplane! or Top Secret!, but more...retro.

The Kingdom - In a rare reversal of form, Eric finds a movie markedly less interesting once people start slinging lead at each other (you could be a gun nut if a dude opens up with a G3A3 on full-auto, gets wee groups, and you actually see verisimilitude exit the screen and walk out of the room). Furthermore, when your movie is clearly a geopolitical fable, you don't need to point out that fact in the coda with the most ham-handed doubling scene ever. The first hour is pretty damned solid.

Walking Tall (The Rock edition) - Is there some sort of award for Worst Cinematic Police Work? Somehow, I can't get over vindictive abuse of 4th amendment rights or handing a self-described convicted felon a shotgun (not that I necessarily have a problem with the felon in question, but COME ON). Way to waste a 'little guy standing up for what's right' premise.

Point Break - COOLEST. MOVIE. EVER.

Face/Off - When Travolta is the 'good guy,' this movie fails entirely. Fortunately, he spends 2/3rds of it as the bad guy, so it works out just fine. Also, any movie with a Stetchkin in it gets an extra star automatically.

Thursday, January 22, 2009

On Recoil Mitigation.

I had myself an apostrophe epiphany vis-a-vis shoulder arms and recoil today.

My usual technique both on the bench and off was to hunch over the rifle for maximum control. The buttstock was resting slightly below the collarbone, and the rest of the shoulder rolled over. The good news was that the muzzle didn't go anywhere. The bad news was that all 14.7 ft-lbs of recoil were deposited directly into the collarbone and surrounding muscles. I am about as far from ripped as it is possible to be, so the net result was my shoulder transmuting to one gigantic bruise after about 40 rounds.

The RO at the saturday night steel shoot talked once about a gentleman at the range shooting a Browning BAR in .300 WinMag, using the same technique, and similarly getting the crap kicked out of him. The RO was shooting a rifle in the same power class, but half the weight, and with no fatigue or bruising. The difference was that the RO used a much looser grip on the gun, and let it pivot up at the shoulder.

Remembering this anecdote, I loaded up the M38 and had another go at it. The recoil pad was centered on the collarbone. When I touched the gun off, I let the muzzle lift 15 or 20 degrees up. A goodly portion of the recoil energy seemed to be used to lift 8 pounds of rifle, and the recoil force at the shoulder was negligible; no lasting pain of any sort. Since it's a bolt-action, follow-up is mechanically limited, so I'm not terribly concerned with control per se.

So this is how a recoil junkie is born...

Friday, January 16, 2009

Lessons Learned.

I practiced "the hard stuff" at the range today - groups at 50 yards, offhand at 15 yards, with liberal doses of ball-and-dummy (because the range I shoot at has plywood stalls that make a .22 sound like a .454 Casull), and you know what? After working uphill for an hour and a half, I was much more satisfied when I left.

I think there may be a lesson here. Geoff Colvin's "Talent is Overrated" talks about "deliberate practice," which is both the only way to get really good and (being intrinsically satisfying) a 'multiplier' - a positive-feedback motivation loop.

So...keys to motivation:

1. Do hard stuff.
2. Do new stuff.
3. Do a lot of 1 and 2.
4. Dry Fire. Fucking loads of dry fire.

Thursday, January 15, 2009

SKS: 10-round impression.

(Yes, this was my first time. There goes my gunnie street cred.)

Wow, this stock is the proper length for the Vietnamese Revolutionary Midget Brigades.

Wow, these notch-and-post sights are almost identical in design to the Mosin's and yet are somehow much easier to acquire.

Wow, this gun is absurdly easy to shoot, once I get past that motherfucking flinching problem.

I think I could go for one of these.

Wednesday, January 14, 2009

On Sampling.

I was watching Blue Velvet the other day...so if I'm hearing this right, Amon Tobin's "Like Regular Chickens" is based around a couple of samples from the soundtrack of said Lynch film. So is "People Like Frank," from the same album.

Heh.

On Gordon Biersch Märzen and Pilsner.

I finally bit the bullet and decided to see what the deal was with Messrs. Gordon and Biersch (yes, the first one has a given name as a surname. Clever bastards.). Mr. Gordon is a graduate of what is apparently a prestigious five-year brewing program in Weihenstephan, Germany. Let's see how it paid off...

Märzen
Short: It's awesome. Hell, everything I've tried in this genre is awesome, which means that I love fruity, malty, full-bodied lagers that retain that classic sparkling hoppiness, and that I probably haven't tried enough Märzens yet. Compared to the caramel-apple roundness of Spaten Ur-Märzen (seasonal, apparently - get thee to the local booze peddler with haste), the GB version is a bit darker and more subdued in character. In fact, it's quite reminiscent of...

Czech-style Pilsner
Darkest 'pilsner' I've tried - it feels like a lager that the brewmasters went postal on with hops. Dry as a Glock's striker channel, and lingers longer than black powder smoke on a still day. Moderate body, with a slight green-apple tang. I could subsist on this stuff for a good long while and not be the least bit disappointed.

In summary, it looks like I'll be perusing Gordon Biersch's manifold offerings in greater depth. Oh hell yes.

On Climate.

Y'know, with all this hullabaloo about Global Warming, it just occurred to me that I haven't heard anything about the Hole In The Ozone Layer since 6th grade...

On Primers.

Well, I won't be stocking up on them for a bit.

Between panic buying and what I have heard and seen to be the usual stocking cycle (large retailer purchases massive lot of reloading components, stock depletes, is re-stocked, often with shortages in common components), I'm down to the 800 loose primers and 1600+ primed cases currently in stock. (And 500+ primed 9mm, but seeing as I don't shoot that caliber much anymore...maybe I should use up those Speer 125gr LRNs and some bullseye, and re-commision the CZ52, or function-check the Tokarev...)

Next time, bulk. Set aside a paycheck and damn the torpedoes.

(Incidentally, magtech primers are pretty good - 15000+ and no complaints.)

Blood pressure...dropping.

Coolest sport ever.

CAS always seemed cool enough, but I never quite got with the western flow. (The Wild Bunch matches sound neato-keen, though...) But same roleplaying-meets-shooting concept in the roaring 20's? Oh yes. Where the dress is actually stylish instead of kitsch, and all the really cool toys come out to play.



I'm looking forward to the pocket pistol side matches (get all Jude Law with a Savage!) , and people 'gaming' the revolver matches with Webleys and 38/44 Heavy Duties, plus retro carry methods (loose cartridges, full-flap holsters)...

Blood pressure...rising.

Remember, kids, this is what passes for 'reasonable' in some circles...

End politics. I can't think of Washington DC without also thinking of Agent 47 on a very...large...retainer. Verdammt.

Thursday, January 8, 2009

Wait a minute.


I, for one, would be quite happy if tomorrow I rolled out of bed in Bizarro USA, where S&W Model 53s are routinely found in police holsters, and the Ruger standard auto series are chambered in 5.75 Velo - I mean, with copper-jacketed BulkFed(tm) running $17/525, who *wouldn't* have five guns in that caliber?

(Yeah, ok, Midway's new website might not be working correctly. A man can dream, surely.)

On Flinching.

All those thousands of posts by people advocating airguns or .22 rifles for a starting shoulder arm? Yes, listen to them. Starting with a Mosin-Nagant M38 will have you flinching with a Diana Model 25 (a delightfully machined chunk of Germanic blued steel that tosses 8.7 grain .177 'diabolo' wadcutter pellets at a leisurely 430 fps with boring accuracy from a 12-groove rifled break barrel).

And I'm not sure whether chunking away with said pelletchucker will cement said flinch or gradually heal it. Bollocks.

(Incidentally, if you shoot steel-cased surplus 7.62x54r, save the cases - they make neato-keen reactive targets. Hat tip to Xavier for the inspiration.)

On Satisfaction.

Tetra Gun (now with Rancid Goat Piss® smell!) + 25 minutes + a nice bronze bore brush = shiny bore - stubborn copper deposits.

Oh hells yes.

For those considering Montana Gold bullets: do it! Best deal on the internet. Just pick up a good bore brush as an ancillary investment.