Young Americans Marksmanship & Safety Association

Helping young Americans learn firearm safety, range safety & proper etiquette. Introduction to the many types of shooting sports. Silhouette, long range, bench rest, service rifle and reloading your own ammunition. Math and history are also taught. Both boys and girls are encouraged to participate. Families welcome.

Instruction is performed by: U.S. Military veteran, former paratrooper, Drill Instructor, accomplished shooter, certified NRA instructor and Range Safety Officer.

This Club has been featured on Television and in the Tribune Newspaper - "Program teaches parents, kids about proper use of firearms." by Abby Weingarten

Rifles

The Barrel

Understanding the separate parts within.

The void, space, or cavity.

The Chamber

Supports the cartridge. The more in line the chamber is with the bore down the barrel, and the more centered the chamber is with the barrels bore, the more accurate any given barrel will be.

The Chamber Throat

Short vs long and the effect of maximum velocities. The effect of longer vs shorter cartridge neck designs on throat life.

While the barrels chamber is insulated from the heat of burning gunpowder by the cartridge brass, the beginning of the rifles bore, the throat, is not. The throat receives the highest temperature within the barrel. Burn out the throat, and with it my barrels accuracy.

Maximum bullet speed produces maximum heat in the throat, wearing my barrel out early. This effect can be reduced while still keeping higher bullet speed when I use a slower burning powder in my loads. The slower powder burns longer, continuing to make expanding gas pressure as the bullet travels down my barrel. Slower powders work best with a longer barrel.

Rifling

Types & styles

Obermeyer R-5, broached, polygonal and hammer forged are common types. It remains the subject of clubhouse debate as to weather one is better than the other, provided each is done well by the barrel maker. Some makers now provide progressive twist rates in their rifling process. The barrel starts at one twist rate and then gets faster.

The Crown

The last part of my barrel to touch the bullet. There are round, recessed and eleven degree target crowns. The crown not only protects the rifling from possible damage, it must evenly release the hot gases out into the air. If it's not perfect, it will disturb the bullet just as it leaves the barrel.

Barrel Resonance

There are several factors that contribute to barrel vibration. Certainly, the combusting gunpowder is a large factor, as each powder burns with different caracteristics and therefor imposes it's own unique harminics within the barrel. Some barrels have minimal stress contained within the steel, while others still have a lot of stress following the manufacturing process. The harmonic pattern of a barrel is spiral, not just up and down. This is due to the torque effect caused by the rifling twisting the bullet. Each time a bullet leaves my barrel, the harmonic spiral pattern is potentially different. Consequently, the bullet strikes the target at a different location. A heavy target barrel reduces harmonics and also stablizes the harmonic pattern allowing repeat performance at the target. A thin barrel may improve from a harmonic dampening aid such as the BOSS or a barrel boot.

Size Does Matter

Thick or thin, long or short. I choose my rifles barrel based on how I use my rifle, or how far I will have to carry it. A fluted barrel performs like a barrel larger in diameter, while feeling lighter in my hand. A shorter 20 - 22" barrel is usually enough length for the volume of modern ball powders contained in .308 winchester and smaller cartridges to completely burn. Higher volume cartridges of 30-06 size and the large magnums benefit from longer barrels that contain the bullet long enough for all the powder in these cartridges to completely burn. Barrel length is determined by the cartridge for which the barrel is chambered, how far I will carry it in the field or rest it on a target bench, and how much barrel resonance to eliminate using the barrels size to control it.

The Role of the Cartridge

Initially a holder, then a gasket. Some are revered while others are scorned.

Cartridge Design

It effects how well, or poorly, a given cartridge reliably feeds into the chamber of a gun. The latest designs from the gun makers are short, fat cartridges. This obviously will not slide out of the magazine of a bolt action rifle as reliably as a longer, narrower cartridge.

The neck length, and how closely it matches the diameter of the bullet will affect the barrel's throat life. Example, a cartridge holding a quarter inch (.25) diameter bullet should have at least a quarter inch long cartridge neck. As the hot burning gunpowder exits a bottle neck cartridge, the shoulder angle of the cartridge directs, or deflects, the hot gases more toward the sides of the barrels throat. A longer cartridge neck design tends to shield the barrels throat from this effect and cause the hot combustion gas flow to be straightened down the barrel. A cartridge with a longer neck to bullet diameter ratio can usually be loaded to higher bullet velocities without shortening barrel life due to a heat eroded throat. A longer neck allows any bullet to be seated in the cartridge farther out, allowing more gunpowder into the cartridge and potentially higher bullet velocity, assuming the rifles magazine box is long enough to allow bullets to be seated out farther.

Single shot rifles do not have this space restriction.