A year ago I bought 8GB of DDR3 RAM for $45. I just bought another pair of DIMMs with identical specs and paid $77. Prices spiked to this level during 2013 Q1 and have not retreated, in what seems a blatant market violation of Moore’s Law. Some commentary on this situation notes that historically DRAM producers have whipsawed between cutthroat competition and nearly (if not explicitly) collusive pricing power.
A few months ago I discussed metals and coatings for firearm actions. I noted the NiB (nickel-boron) gets discolored by fouling, but my photos only showed a sparkling new NiB-X BCG. Following is a picture of what it looks like after a few hundred rounds of use, followed by ultrasonic cleaning and then aggressive scrubbing with steel and brass wire brushes. For comparison I show my heavily-used chromed BCG on top.
Is this just a cosmetic issue? This is the only cleaning I’ve given the NiB BCG. I haven’t lubed it and I have subsequently run a few hundred rounds more without any action failures. However it seems plausible that if fouling can bind to the surface this stubbornly it could build up to the point of overtaking the nickel-boron’s lubricity and causing a stoppage that only traditional lubricants prevent. As noted in the original article this is not a problem with chrome and NP3: All photos of those to date have been after they were used and wiped clean with minimal brushing.
I reload for half a dozen guns in .308 Winchester. Reloading is a lot easier if you only have to neck-size fired cases. Until recently I kept all brass segregated by rifle, and only “full-length” case-sized brass that came out of semi-autos (which are under enough pressure during extraction to bulge the case body). Then I thought I’d get clever and see if any chambers were cross-compatible, allowing me to use brass fired in one gun in others without full resizing. Sure enough, a handful of fired cases suggested that all my bolt-guns were interchangeable.
However, since this apparent epiphany I have broken a CTR stock, a Savage bolt handle, and five cleaning rods in the process of extracting rounds stuck in chambers. I have also resolved to small-base-size any case that isn’t being reloaded for the bolt gun in which it was last fired. Here are some nuances I’ve learned.
Evidently fired case size isn’t consistent. Even though I’ve been using a single lot of brass, not all loads fully form the case to the chamber. Presumably even if I stuck with the same load the brass would exhibit different springback on subsequent reloadings as it work hardens.
I eventually discovered that my DTA chamber has a relatively large base, which led to my other painful discovery: “full-length” rifle sizing dies do not necessarily size the whole case. For example, when properly set, my Lee full-length .308 die doesn’t even cover the bottom quarter inch of a case. Only a “small-base” sizing die will ensure the entire case is squeezed back into spec.
My other irritating discovery is that few “case gauges” check for full chamber fit. The Wilson case gauges I had been using all along are actually overbored to ensure they can measure fire-formed brass. They are only meant to check headspace and trim length. The fact that a case clears a Wilson gauge is insufficient to determine whether it will chamber in any gun. The only gauge I could find to guarantee chamber fit is the blue JP Enterprises one in the middle of this picture:
The JP gauge is cut to the minimum SAAMI chamber spec, which means that if a round clears it and fails to chamber you’ve got a chamber problem, not a case size problem. But we’re talking about very fine tolerances. The round in the JP gauge in the picture is actually oversize enough to jam in my Savage. You can barely tell that by looking, but you can feel the base protruding ever-so-slightly at the rear of the gauge.
Read the rest of this entry »
This sequence shows me discharging a loaded round I couldn’t disassemble. There is no reason to ever do something like this other than brazen curiosity. If you want to disable a live round you should pull the bullet and dump the powder. If for some reason that fails a safer alternative to discharging it is to “cook it off” in an open pit fire. (Ensure that anyone not wearing a face shield and thick clothing stands clear until it pops.)
Firearm cartridges are not particularly powerful or dangerous unless they are tightly confined. Without a gun barrel to contain and direct the pressure smokeless powder burns slowly, if at all, and bullets are propelled only by the force of the primer. (Granted, primers are not toys. They are true explosives. Small firearm primers produce 5-10 foot-pounds of energy, and can produce pressures on the order of 25kpsi in a small closed chamber. Like firecrackers, they can burn and maim.)
The round I had on my hands contained a full load of powder that turned out to be too fast for the bullet. I managed to pull the rest of the batch, but one bullet came out and left its copper gas check in the case. In that condition it could have been safely fired in a gun, except that it could have badly fouled the bore depending on how the gas check engaged it. So instead I drilled a hole in a piece of wood to tightly hold the case neck, put on leather and a face shield, then detonated the primer with a steel punch.
An integral pulled bullet and case are shown left. The hand-fired case and bullet missing its gas check are on the right.
The problem with any containment when discharging a round is that without experience and knowledge of the case and powder you may be surprised at where the force ends up. The unsupported case could become a projectile or fail and produce shrapnel. The bullet and any other particles in the path of the venting gases can also be ejected almost anywhere. The setup above was carefully planned to allow for the worst possible outcome in every dimension. What actually happened is that the case neck held fast in its hole in the upper plank and the unsupported annealed upper body was blown out by the pressure, but did not fail. The gas check ended up embedded in the bottom plank directly below, and the gas was able to vent out the gap between the planks, blowing only minor wooden debris along with it.
- Supply in the firearms industry is finally starting to converge on demand. But reloaders are still grasping for powder, and .22LR is still absurdly scarce. We’re looking for both of those shortages to end by the middle of this year.
- Expanding subsonic rifle bullets: Looks like this is finally the year for these to hit the mainstream market. Outlaw State Bullets and Lehigh Bullets have had some expensive offerings. But this year Norma is supposed to begin importing their Plastic Points, and Remington should finally have an offering tailored for their 300BLK.
- .38 Supercomp Sig and Glock conversions. The caliber offers the ballistics of .357 Sig in the diameter of 9mm, which translates to more magazine capacity. Also, as a straight-walled cartridge it’s easier to reload.
- Laser Doppler Anemometers: Solid-state devices for shooters, similar to laser rangefinders, that can measure downrange winds. Winds are the last primary ballistic factor that can’t be measured outside instrumented ranges. Even the most skilled long-range marksmen in the field have limited indicators from which to read and compensate for windage. Admittedly this technology is still some years off from commercialization.
- Chemical laser guns. Well maybe not this year, but the technology is there for it.
- New cars to display more of the performance data easily accessed from the existing ECU streams, including most critically whether the fuel in the tank is causing the engine to retard timing.
- Aftermarket OBD scanners to do the same for existing cars.
- High-performance minivans.
- High-speed consumer video cameras: GoPro may be inching back into this niche left by Casio four years ago. Their top offerings can now sustain 240fps at 480p, but I’m still looking for thousands of frames per second in a sub-$1000 camera, which is no stretch given the state of the art.
- Reasonably-priced HD IP security cameras: For some reason these persist at over $200 when the state of the art should have them closer to $100.
- Digital thermal and night-vision gear: No manufacturer seems to want to lunge for the tipping point. Equipment that is currently produced at a small scale, and therefore costs 4- or 5-figures, could be profitably mass-produced and sold for 3-figures to the sport and non-military security markets.
The Barrett MRAD is a $5800 precision multi-caliber bolt-action rifle, shown here with a 24″ barrel in .338 Lapua Magnum, and a $500 quick-detach LRA bipod. The MRAD sets new standards in modularity, simplicity, and compatibility by combining a number of clever design features:
- Like most modular rifles its folding buttstock locks into place over the bolt handle. It adjusts for length-of-pull with a button, cheek height with a thumbscrew, and features a bottom rail for mounting a monopod.
- The upper is a beautifully milled if oddly anodized piece of aluminum with 30MOA of cant in the top rail.
- It uses robust and reasonably priced double-stack injection-molded 10-round magazines. (However they can only hold rounds up to 3.8″ long, which may limit the reloading envelope of heavy VLD bullets.)
- Upper and lower receivers separate with one lever and one captive drift pin.
- It accepts standard AR-style grips. It is shown here with a Magpul MOE.
- It uses a traditional AR-style short-throw safety.
- The bolt has an automatic self-lubricating dust cover.
- Its barrel can be rapidly changed out the front after removing two bolts, and reinstalled without losing zero.
After pivoting the gun open the bolt comes straight out. The safety can be pushed out without tools at which point the trigger module can be lifted out. The trigger itself deserves special attention: It is as simple as can be and elegantly executed. Adjustable down to 1.5 pounds, it breaks shots consistently with no creep or overtravel — an ideal specimen for precision shooting.
And this rifle is precise! Following is the very first group shot at 300 yards after zeroing at 200 yards. Using my preferred handload with Lapua brass and 250gr Lapua Scenars this 5-shot group is right about 0.6MOA.
As shown the rifle weighs over 17 pounds, so it makes shooting the heavy .338LM quite tolerable. After several years of delays Barrett is just now bringing caliber conversion kits to market for $1500, allowing owners to switch bolt, barrel, and mags to shoot lighter, cheaper .308 or .300WM from the same gun.
The only shortcoming as delivered is that the bolt knob is a cheap piece of injection-molded plastic. Presumably it is meant, like that standard grip, to be replaced by the end user with his preferred bolt handle.
In 2008 the US Special Operations Command (SOCOM) began soliciting a new “Precision Sniper Rifle” (PSR) to fill the gap between the .308 M24 and .300WM M2010 (both manufactured by Remington) and the M82/M107 .50BMG rifles (by Barrett). The primary cartridge for the PSR is the .338 Lapua Magnum.
A unique objective of the PSR program was to procure a system that would allow for rapid barrel changes in the field, including conversion to fire the smaller .300WM and .308 calibers using the same chassis and optic. The precision specification was already quite demanding — a consistent vertical spread of no more than 1MOA over a statistically significant number of trials. Constructing a system in which a barrel could be removed from the action in the field and then returned to the same zero may have previously be unthinkable.
It turns out plenty of civilian shooters were just as interested in owning a multi-caliber precision rifle. Shown here are three that were designed for the PSR program and made available for sale to the civilian market.
On top is the Barrett MRAD. Initially offered only in .338LM for $6000, Barrett just brought its $1500 conversion kits (bolts, barrels, and magazines) to the market.
In the middle is Accuracy International’s PSR, currently sold only as a complete kit with all three calibers for $17000.
Bottom is the bullpup Desert Tactical Arms SRS, the bargain of the group at $3000 for the chassis and roughly $1500 per caliber kit. We previously reviewed the DTA SRS. Of the multi-caliber PSRs it currently seems to have the greatest market penetration. It is also available in the widest array of calibers, and even has third parties manufacturing conversion barrels.
The PSR contract was finally awarded this March to Remington’s “Modular Sniper Rifle,” which will probably not be available for civilian purchase until government demand has been satisfied.
These are the rifle cartridges in common use by modern western militaries. The smallest is the standard NATO infantry round, 5.56x45mm. Adjacent on the left is the “medium” 7.62x51mm, also a common infantry round, especially in theaters where longer engagement distances render the 5.56 ineffective. Middle is .300 Winchester Magnum (.300WM), which has long been fielded for snipers needing to push beyond the 1000-yard “effective” range of the 7.62mm NATO. The .300WM is being supplanted by the fourth cartridge, .338 Lapua Magnum (.338LM), which has emerged as the top long-range military sniping cartridge. Previously, long-range snipers often relied on the largest of the “small arms” cartridges: the century-old “heavy” .50 Browning Machine Gun (.50BMG) round.
The following table lists the size, weight, and range of each cartridge for typical military loads, barrels, and sea-level atmospheric pressure. The point at which bullets slow through roughly 1100fps is a common benchmark for range because that is the speed of sound at typical air temperatures. Historically the accurate range of a precise bullet has been limited by the effects of crossing through the sound barrier. However, modern barrels tend towards faster rifling twist rates which increase transonic stability. In the last decade snipers have recorded first-shot kills at ranges where their bullets were subsonic. Snipers at high altitudes have made a number of remarkable kills at distances of up to 2700yds. The thinner air at high altitudes creates less drag on bullets and thus extends their range.
|Caliber||Cartridge||Weight||Length||Bullet||Energy at 1100fps||Standard Barrel||Muzzle Velocity||Range to 1100fps|
|MK318 Mod 0||180gr||2.26″||62gr OTM||170 ft-lbs||14″ (M4A1)||2925fps||730 yds|
|20″ (M16A2)||3130fps||780 yds|
|M118LR||400gr||2.80″||175gr OTM||475 ft-lbs||20″ (M110)||2570fps||970 yds|
|24″ (M24A1)||2640fps||1000 yds|
|.300WM||MK248 Mod 1||490gr||3.50″||220gr OTM||600 ft-lbs||24″ (M24A2)||2850fps||1400 yds|
|.338LM||680gr||3.68″||250gr||680 ft-lbs||27″||3000fps||1525 yds|
|730gr||3.85″||300gr||820 ft-lbs||2800fps||1700 yds|
|.50BMG||M1022||1750gr||5.45″||650gr||1780 ft-lbs||29″ (M107)||2750fps||1500 yds|
On the heavy end it’s interesting to see that the .50BMG is actually at a disadvantage to .338LM in terms of range (not to mention the added weight of the rounds and heavier guns needed to efficiently shoot it). But it does have the capability of delivering more than double the payload, so it is still in use for anti-materiel roles.
Read the rest of this entry »
If you’ve read some of the recent articles on ballistics, especially the comments on this one, you might logically deduce that for any gun the best bullet is the lightest you can find. After all, lighter bullets produce less recoil and more muzzle energy. How can you lose?
It turns out a number of companies have come and gone trying to exploit this argument to sell extremely light, fast bullets, especially for handguns. Liberty Ammunition is the latest on the scene. A detailed critique of previous ventures that includes extensive explanation of the problem with ultralight bullets is archived here.
The short answer is that very light bullets are very bad for defensive use because they lack penetration, and companies that sell them for that purpose are guilty of misleading advertising. Yes, at short ranges they “dump” more kinetic energy into targets, but that energy does not create the deep wound channels experts know are necessary to physiologically stop aggressive animals (including people) in typical shooting scenarios. That’s the end of the argument as far as consumers are concerned.
I will make two other esoteric observations: First is that on the low end ballistic efficiency decreases with bullet weight. The second is that sectional density decreases with weight, which means that ultralight bullets lose speed (and energy) faster and are more susceptible to deflection in flight.
So ultralights suffer impairments at every stage of ballistic consideration: internal, external, and terminal. At short range their extraordinarily high velocity does enhance penetration through some materials, but that does not mitigate their drawbacks. If you have a specific scenario that requires penetration you should get a rifle and load suited to it. Never load your defensive handgun with ultralight bullets!
The LaRue OBR represents the pinnacle of autoloading medium-caliber rifles. It’s not the only premium AR-10-pattern gun on the market, but it’s probably the best deal. The base rifle is just over $3000 … plus a wait currently running about eight months. Fit and finish on this hand-built gun is superlative. In fact, the tolerance between the upper and lower was so tight I had to use a rubber mallet to separate them at the rear takedown pin.
The 18″ .308 caliber model here has been kitted up with LaRue’s quick-detach scope mount ($264), a $2200 Nightforce F1 NXS scope, Atlas QD bipod ($280), and $1250 Thunder Beast 30BA suppressor. Suppressor compatibility is one of the great features of this gun: It has a port selector on the gas block that toggles to the right to reduce blowback when shooting with a suppressor. And, since even that won’t prevent carbon fouling of the action, most of the BCG has a polished chrome finish that wipes clean — shown here cleaned after its first extended range session:
The rifle comes with two of LaRue’s M110 20-round magazines, which are slicked-up boxes with a fully-welded seam in the rear to maximize loadable cartridge length. Additional LaRue mags run $75/apiece.
A couple of sons joined us for the rifle’s inauguration. After we sighted in at 200 yards a 90-pound 12-year-old with little experience was able to get behind it and ring two 10-inch swinging plates, alternating back and forth with no hesitation, for a full magazine. It was an impressive feat. Before moving to more distant steel I jumped on it and took the first four shots at 300 yards with my 150gr handload optimized for 18″ barrels:
With both 168gr FGMM and this handload the rifle is easily a 1/2 MOA gun.
The trigger is a crisp Geissele SSA two-stage, with about two pounds on each stage. When given the choice I opt for single-stage triggers, but on a rifle designed for the most grueling field conditions I can agree that a two-stage offers an extra layer of control while still allowing for the precision of a light pull.