Rifle Primer

[Spectre]

(text by Ken Cox; much of this may be known to the readership, but given the large number of "new recruits", I was certain some would find this helpful)

The definition of the Main Battle Rifle has changed so much over the years. The term itself may only have appeared, come and gone, in recent times; I think it may have come from the pen of Jeff Cooper. We now
hear the term applied to assault rifles, mainly because of the prevalent issue of assault rifles to infantry in the place of Main Battle Rifles.

I recommend the motion picture BARRY LINDON by Stanley Kubrick for some insights into the fashions of war, and how they change with the times and cultures of the antagonists. At one time, men dueled and armies fought by standing a prescribed and absurdly short distance from each other and formally taking turns shooting. As time progressed, the Lords of Death saw that they could turn the course in their favor by cheating a little and shooting out of turn. This led to mass, desperation fire and the Brown Bess musket.
The Brown Bess has no rifling and an oversized bore, for the purpose of
facilitating rapid reload and fire. How discouraging to the two finest armies on the planet, the Prussian mercenaries and the British Redcoats, when the Americans hid behind cover and aimed at individual enemy
soldiers, including officers, with their small caliber, slow loading, rifled barrels.

The Main Battle Rifle culminated somewhere in between the Mauser, the Springfield, the Enfield and the Garand. These rifles weighed close to ten pounds. They fired a powerful, heavy and long-range cartridge, and they could maintain sustained fire rapid fire at the rate of six rounds per minute. They required a highly trained and physically able soldier to man them. One very famous Marine Corps General said he could conquer the world with a regiment of Riflemen. Of course, he meant Marines armed with Main Battle Rifles.

The true Main Battle Rifle allows offensive and defensive fire at all infantry appreciable ranges, from, say, 1200 yards to indoors. It multiplies the effectiveness of the infantryman; and, the skill and athletic ability of the infantryman, in turn, limits the effectiveness of the Main Battle Rifle.

In contrast, the Assault rifle trades power, range and accuracy for volume of fire and low recoil. This allows a relatively unskilled and physically less capable infantryperson to put out large amounts of suppressive noise and threat. The assault rifle represents a
diminishment of the Main Battle Rifle as an accomodation to abbreviated training and a lower level of athletic ability, whether related to age, gender, stature, culture, conditioning or time and material resource
limitations.

The Main Battle Rifle replaces both the Carbine and the Long Range Stand Rifle; and, the Carbine and the Long Range Stand Rifle replace the Main Battle Rifle.

 

[Spectre]

(further text by Ken)

Several things make a rifle more accurate than as it comes from the factory.
These refinements cost a lot of money and have diminishing returns.
The first 1/2" one taked off of a 100 yard group costs a few hundred dollars; the next 1/4" takes a thousand dollars; and then it gets expensive. All of the improvements acheive accuracy by improving repeatability, or consistency, through the reduction of vibration and the disharmonies of vibration. Even with high amplitude vibrations, a
rifle would shoot accurately if provided with absolutely consistent ammunition and consistent atmospheric conditions, such as pressure, humidity and temperature.

When the powder ignites and expands (explodes) and the bullet travels
down the barrel, the barrel resonates like a bell and the muzzle vibrates up, down and around. If the bullet always left the muzzle at the exact same point in the muzzle's cycle of vibration, then we could account for it by adjusting the sights. However, since each bullet arrives at and departs the muzzle at a
slightly different time, in nano-seconds, the bullet departs the muzzle at a different point in its cycle of vibration while the muzzle points in a slightly different direction than any of the other bullets. Some of the Benchrest shooters attempt to overcome this with absurdly heavy and stiff barrels, sometimes 3" thick.

Absolutely consistent ammunition which guarantees that each bullet spends exactly the same amount of time traveling through the barrel does not exist; although serious reloaders and commercial houses can make
ammunition amazingly consistent, nonetheless, variations in ambient temprature amplify even the tiniest amount of variation. Given variations in ammunition and temperature, one returns to minimizing vibration and disharmonious vibration.

One gets the best return on his or her money by glass bedding the barreled action to the stock. This ensures a constant relationship of action and stock and consistent vibrations. You can do this at home
with a kit from Brownell's, or you could pay a gunsmith $50-$150 to do it for you.

Blackstar treatment takes the barrel through a cryogenic cyle which relieves internal barrel stress and allows the barrel to vibrate or resonate more consistently over a wider range of ambient and shooting
temperatures. Blackstar also smooths the inside of the barrel, apparently more so than any other method, and in the process tapers the bore .004" from bore to muzzle. These efforts result in extended barrel life and higher velocities. I believe Blackstar does a barreled action for less than $250.

The two measures above give the most dramatic and cost-effective improvement in consistency, or as we think of it, accuracy.

Now, one can have the face of the bolt and the lugs trued so that the bolt face and base of the cartridge always have a perpendicular and centered relationship to the bore of the barrel. This reduces vibration. How much? Perhaps in no measureable amount. I don't know how much this costs.

Next, one can have the barrel removed; the gunsmith drills a new hole in the receiver for the barrel, supposedly better centered and aligned with the bore, and re-threads the hole; the gunsmith then takes a barrel blank from someone like Krieger and chambers and threads it to match the receiver; and then he puts it all together.. If the gunsmith can do a more prescise job of this than the factory did, it might improve accuracy and it might not. Regardless, it cost mucho bucks.