The 6mm PPC, or 6 PPC as it is more called, is a centerfire rifle cartridge used exclusively for benchrest shooting. At distances out to 300 meters, it is one of the most accurate cartridges available; this cartridge's accuracy is produced by a combination of its stout posture, being only 31 mm long, aggressive shoulder angle of 30 degrees compared to a 30-06's 17 degrees. Today it is used for railgun shooting matches and has been since the 1980s; the cartridge is a necked-up version of the.22 PPC, in turn based on a.220 Russian. The standard bullet diameter for 6 mm caliber cartridges is.243 inches, the same diameter used in the.243 Winchester and 6mm Remington cartridges. To obtain maximum accuracy, bullet weight and form are matched to the rifling twist rate of the barrel. 68 grains bullets are used in barrels with twist rates of 1 in 13 inch, while 1 in 15 inch barrel twists can accommodate lighter 58 or 60 grains accurately. The cartridge developed enough acceptance; the parent cartridge for the 6PPC is the.220 Russian.
Brass can either be formed from.220 Russian brass. During the early development accuracy experts noted that concentric thickness of the cartridge neck were beneficial in lining up bullet to the bore - a feature lacking in commercially available brass of the time. Most 6PPC chamber reamers are ground with a tight neck section that requires removing some case neck material to create a cartridge with a concentric fit and consistent neck-to-chamber clearances which contribute to the 6PPCs accuracy. While the SAAMI specification for neck thickness in a 6mm cartridge is usually.272 inches, it is common to see 6PPCs with.262 inches.268 inches, or.269 inches custom neck sizes, hence modern factory ammunition is not produced for the 6PPC as it would be dangerous to shoot in these custom chambers. To help clarify this, factory guns and ammunition are specified as the "6PPC-USA" cartridge which has a CIP/SAAMI specification. To the Note that a neck expanded, "unturned" and loaded.220 Russian case neck will always be larger in diameter than the 6PPC rifle's chamber neck.
It is important to understand the characteristics of one's chamber before starting, which can be checked with a tool such as a "chamber cast". Alternatively, one can use a manufacturer's print of the chamber or a print of the reamer used to cut the rifle chamber. Cartridge Case Preparation Method One The.223 inch neck of the.220 Russian is expanded to.243 inches using a mandrel the headspace is set using a full length sizing die for 6mm PPC. Next the case is trimmed and fire formed by firing the round in the chamber of a 6mm PPC rifle; this way the shoulder of the.220 Russian case have become blown forward to 30 deg and the case walls have been straightened, allowing for greater powder capacity. Competitors will turn the neck walls of their case to a uniform given thickness, so that a loaded cartridge's neck diameter is just a few hundreds of a millimeter less than that of the chamber's neck. European cartridge manufacturers Lapua, Norma and SAKO have begun making 6mm PPC brass. Cartridge Case Preparation Method Two Starting with a.220 Russian case to be turned into a blank cartridge for fireforming.
First the case is lubricated and full length sized in a 6PPC die with the expander button removed. A small pistol primer is inserted into the case to be converted.. A large quantity of fast burning pistol propellant is added to the case, it is of high importance that the propellant is of a fast burning type. For this cartridge, some have reported 16 grains of Bullseye® powder working well; some paraffin wax is melted into the lid of a jar or something similar, when it solidifies, the lid is turned over, pressing it over the neck of the now loaded blank cartridge, making a seal that will both keep the propellant in the case and provide a modest resistance to the propellant when it is fired. The case is generously lubricated with a high quality case sizing lubricant, of which Imperial Sizing Die Wax is a popular variant; the cartridge is placed into the rifle and fired to get what is called a "fireformed case". Fireforming in general gives a large muzzle blast; as overheating can shorten the life of the barrel, many will take short breaks between when several cases are to be fireformed.
Some check this by touching the barrel, will take a pause if the barrel is to too hot to be held. After the fireforming is finished it is normal to clean the chamber to remove any traces of lubricant, as lubricant in the chamber can increase the force on the bolt when firing live ammunition; the fireformed brass is cleaned around the neck to remove lubricant and powder residue. The cases are run through a 6 mm neck expander, which will be oversized; the length is trimmed to 1.486 inches, although this
.243 Winchester Super Short Magnum
The 243 Winchester Super Short Magnum or 243 WSSM is a rifle cartridge introduced in 2003. It uses a.300 WSM case shortened and necked down to accept a.243in/6mm diameter bullet, is a high velocity round based on ballistics design philosophies that are intended to produce a high level of efficiency. The correct name for the cartridge, as listed by the Sporting Arms and Ammunition Manufacturers' Institute, is 243 WSSM, without a decimal point. Winchester has discontinued the manufacture of 243 WSSM ammunition; as of the first half of 2016, Winchester/Olin did manufactured and release for sale some WSSM ammunition. The product is only manufactured periodically on inconsistent intervals; the 243 WSSM is an addition to the Winchester Super Short Magnum family of cartridges, which include the.223 WSSM and the.25 WSSM, the idea behind the 243 WSSM was to develop a compact, higher velocity version of the well-established and internationally popular.243 Winchester unveiled by Winchester in 1955. The 243 WSSM was first introduced in 2003.
The 243 WSSM's case is unusually short and fat in profile, contrasting markedly with most other rifle cartridges, is intended to take advantage of what ballisticians have shown is the more uniform and efficient burning of propellant powder when it is held in a short, fat stack by the cartridge case. In their ballistics tables, Winchester list a high muzzle velocity of 4,060 ft/s with a 55-grain projectile for this cartridge. Based on Hodgdon reloading data typical velocities should range from 4,000 ft/s with a 58-grain bullet to 3,000 ft/s with a 100-grain bullet; the percentage gain in performance over the older.243 Winchester is around 10% or less. This cartridge is used for small game such as varminting, used for animals as large as deer. Compared to other factory 6mm sporting cartridges the 243 WSSM is capable of functioning in the AR-15. Other factory produced 6mm cartridges like the 243 Win. and 6mm Rem. are both too long for the AR-15 and require the AR-10 platform. The 243 WSSM is 3/8 inch shorter than the 243 Win. giving the 243 WSSM the ability to fit in a super-short action rifle.
Thus 243 WSSM rifles can have stiffer actions and have faster actions to cycle. The 243 WSSM gives a 10% increase in velocity over the 243 Win. List of rifle cartridges Table of handgun and rifle cartridges Cartridge Dimensions at Steves Pages 243 WSSM – The Long-Awaited 6 mm "Answer"? By Bill Prudden The 243 WSSM by Chuck Hawks The Experts Agree The WSSMs are Winners! Browning The 243 WSSM at Guns & Ammo Hunting experiences with the 243 WSSM 243WSSM.com
The.308 Winchester is a rimless, bottlenecked rifle cartridge and is the commercial cartridge from which the 7.62×51mm NATO round was derived. The.308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62×51mm NATO T65. Winchester branded the cartridge and introduced it to the commercial hunting market as the.308 Winchester. Winchester's Model 70, model 100 and Model 88 rifles were subsequently chambered for the new cartridge. Since the.308 Winchester has become the most popular short-action, big-game hunting cartridge worldwide. It is commonly used for civilian hunting, target shooting, metallic silhouette, bench rest target shooting, metal matches, military sniping, police sharpshooting; the short case makes the.308 Winchester well-adapted for short-action rifles. When loaded with a bullet that expands, tumbles, or fragments in tissue, this cartridge is capable of high terminal performance. Although similar to the military 7.62×51mm NATO specifications, the.308 cartridge is not identical, there are special considerations that may apply when mixing these cartridges with 7.62×51mm NATO, and.308 Winchester chambered arms.
Their interchange is, considered safe by the Sporting Arms and Ammunition Manufacturers Institute. The.308 Winchester has 3.64 ml cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions..308 Winchester maximum C. I. P. Cartridge dimensions. All dimensions in millimeters and inches. Americans would define the shoulder angle at alpha/2 = 20 degrees; the common rifling twist rate for this cartridge is 305 mm, 4 grooves, Ø lands = 7.62 mm, Ø grooves = 7.82 mm, land width = 4.47 mm and the primer type is large rifle. According to the official C. I. P. Rulings the.308 Winchester can handle up to 415.00 MPa Pmax piezo pressure. In C. I. P. Regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C. I. P. pressure to certify for sale to consumers. This means that.308 Winchester chambered arms in C. I. P. Regulated countries are proof tested at 519.00 MPa PE piezo pressure.
North American SAAMI maximum pressure for the 308 Winchester is 430 MPa. The.308 Winchester is one of the most popular hunting cartridges in the United States, the world. It has gained popularity in many countries as an exceptional cartridge for game in the medium- to large-sized class. In North America it is used extensively on whitetail deer and the occasional caribou or black bear. Clay Harvey, an American gun writer, says it is usable on elk. Layne Simpson, an American who has hunted in Sweden, says he is surprised how many hunters there use the cartridge. Craig Boddington was told by a Norma Precision executive that the.308 Winchester is one of Norma's best-selling calibers. In Africa the.308 Winchester is one of the most popular calibers among Bushveld hunters and is used on anything from duiker right up to the massive eland. Proponents of the hydrostatic shock theory contend that the.308 Winchester has sufficient energy to impart hydrostatic shock to living targets when expanding bullets deliver a high rate of energy transfer.
While.308 Winchester has traditionally been the most popular cartridge in the past, the development of lighter recoil chamberings with sufficient downrange energy, like the 7mm-08 Remington.260 Remington, 6.5 Creedmoor, is becoming more common for metallic silhouette shooting. The PALMA shooting is a variant of full bore target shooting done with a bolt action rifle in 7.62mm NATO caliber and fire Match Grade 155 grain bullets using micrometer aperture sights at out to 1,000 yards. F-Class is a variant of Fullbore Target Rifle which permits optical telescopic sights and shooting rests at the front and rear, such as a bipod and/or bags. Competitions are fired at distances between 300 and 1200 meters, the targets are half the size of those used in traditional Palma shooting. Based on equipment, competitors can choose to compete in one of the two classes Open or Standard: F-TR: A restricted class permitting a scope, bipod/ backpack and rear bag, but the caliber has to be either.223 Remington or.308 Winchester.
In addition, the weight limit including optics is 8.25 kg. The.308 Winchester has more drop at long range than the.30-06 Springfield, owing to its lower muzzle velocity with most bullet weights. Cartridges with higher muzzle velocities, such as the.300 Winchester Magnum can have less drop at long range, but much higher recoil. Several more cartridges have been developed using the.308 Winchester as a parent case, some becoming popular for hunting in North America. These are the.243 Winchester, the.260 Remington, the 7 mm-08 Remington, the.338 Federal, the.358 Winchester. In 1980, two rimmed cartridges based on the.308 Winchester were introduced for use in the Winchester Model 94 XTR Angle Eject rifle: the.307 Winchester and the.356 Winchester. In 2014, the rimless 45 Raptor was introduced to provide a big bore cartridge for the AR-10 by combining the.308 Winchester with the.460 S&W Magnum..30 RAR Delta L problem Hydrostatic shock List of firearms List of rifle cartridges Table of handgun and rifle cartridges Sectional density Ultra-h
A rim is an external flange, machined, molded, stamped or pressed around the bottom of a firearms cartridge. Thus, rimmed cartridges are sometimes called "flanged" cartridges. All cartridges feature an extractor or headspacing rim, in spite of the fact that some cartridges are known as "rimless cartridges"; the rim may serve a number of purposes, including providing a lip for the extractor to engage, sometimes serving to headspace the cartridge. There are various types of firearms rims in use in modern ammunition; these types are rimmed, semi-rimmed, rebated rim, belted. These categories describe the size of the rim in relation to the base of the case; the rimmed cartridge, sometimes called flanged cartridge, is the oldest of the types and has a rim, larger in diameter than the base of the cartridge. Rimmed cartridges use the rim to hold the cartridge in the chamber of the firearm, with the rim serving to hold the cartridge at the proper depth in the chamber—this function is called "headspacing".
Because the rimmed cartridge headspaces on the rim, the case length is of less importance than with rimless cartridges. This allows some firearms chambered for similar rimmed cartridges to safely chamber and fire shorter cartridges, such as using.38 Special cartridges in a.357 Magnum revolver. Rimmed cartridges are well suited to certain types of actions, such as revolvers and break-action firearms, where the rim helps hold the cartridge in position. Rimmed cartridges do not work quite as well in firearms that feed from a box magazine, since the magazine must be loaded so that the rim from each successive case is loaded ahead of the round beneath it, so the round will not snag on the rim of the cartridge below it as the bolt strips it out of the magazine. However, box magazine firearms firing rimmed. Semi-automatic handguns have been chambered in rimmed cartridges as well, for example a LAR Grizzly or Desert Eagle in.357 or.44 Magnum. Some types of rimmed cartridges, such as rimfire cartridges use the rim to contain the priming compound used to ignite the cartridge instead of a centrally-mounted primer such as used in centerfire cartridges.
Under the metric cartridge designation system, a capitalized "R" added at the end of the designation denotes a rimmed cartridge. For example, "7.62 × 54mmR" is a rimmed cartridge. Under Imperial designations, there is no distinction between rimmed and unrimmed cartridges, unless one is referring to a rimmed version of a cartridge, rimless, such as the.45 Auto Rim, a special rimmed version of the.45 ACP, intended for use in M1917 service revolvers. Examples of rimmed handgun cartridges include.44 Magnum. Rimmed rifle cartridge examples include the.22 Hornet.303 British and 7.62×54mmR. On a "rimless" case, the rim has or the same diameter as the base of the case. Since there is no rim projecting past the edge of the case, the cartridge must headspace on the case mouth, for a straight walled case, or on the case's shoulder for a bottlenecked case; the lack of a projecting rim makes rimless cases feed smoothly from box magazines, they are used in firearms that feed from a box magazine, although they work well in belt and tube-fed weapons.
Rimless cases are not well suited to break-open and revolver actions, though they can be used with appropriate modifications, such as a spring-loaded extractor or, in a revolver, a moon clip. Since a straight-walled rimless cartridge is designed to headspace off of the case mouth, this prevents the ammunition loader or manufacturer from using a heavy crimp, a ring pinched or "crimped" into the cartridge case, designed to lock the bullet securely in place until fired. Crimping affects the overall length of the cartridge, thus cannot be used on cartridges which headspace on the case mouth; this can be a problem for magnum revolvers or rifles which hold more than one round of ammunition, as the recoil from the firing successive rounds can loosen the bullets in the remaining cartridges, cause their bullet seating depth to change, which can have a serious effect of accuracy. This is not an issue for break-action single shot firearms, for obvious reasons, although it could cause problems in double rifles or "drilling"-type big game rifles, provided they have more than one rifle barrel.
Examples of rimless handgun cartridges include the 9mm Parabellum.40 S&W, and.45 ACP. Rimless rifle examples include the.223 Remington.308 Winchester.30-06 Springfield and 7.92×57mm Mauser. On a semi-rimmed case the rim projects beyond the base of the case, though not as much as a rimmed cartridge; the tiny rim provides minimal interference feeding from a box magazine, while still providing enough surface to headspace on. Semi-rimmed cases are less common than the other types. The.38 Super, a higher pressure loading of the old.38 ACP case, is notorious for being less accurate than rimless cases, so most modern.38 Super handguns are chambered so that the cartridge headspac
The.257 Roberts known as.257 Bob is a medium-powered.25 caliber cartridge. It has been described as the best compromise between the low recoil and flat trajectory of smaller calibers such as the.22 and 6mm, the strong energy but not the strong recoil of larger popular hunting calibers, such as the 7mm family and the popular.30-06. Many cartridge designers in the 1920s were creating various.25 caliber cartridges. Because of its size, the 7×57mm Mauser case was a common choice, having near the ideal volume capacity for the "quarter-bore" using powders available at that time. Ned Roberts is credited with being the designer for this cartridge idea. In 1934 Remington Arms chose to introduce their own commercial version of such a cartridge, although it wasn't the exact dimensions of the wildcat made by Roberts, they called it the.257 Roberts. From its introduction until the appearance of more popular 6 mm cartridges such as.243 Winchester and 6mm Remington, it was a popular general purpose cartridge.
Today, although overshadowed by other cartridges, it lives on with bolt-action rifles being available from some major manufacturers. Japanese Type 38 Arisaka rifles brought to the United States as wartime souvenirs were sometimes converted by rechambering to utilize more available.257 Roberts cartridge cases because commercially produced 6.5×50mm Arisaka cartridges were scarce prior to distribution by Norma Projektilfabrik A/S. The neck of the Roberts case would be enlarged to accept handloaded 6.5 mm bullets. The modified Roberts cases are sometimes known as 6.5×.257 Roberts, although the case headstamp may still indicate.257 Roberts. Neither unmodified.257 Roberts ammunition nor the original 6.5×50mm Arisaka ammunition are suitable for firing in rechambered Arisaka rifles. With light bullets the.257 produces little recoil and has a flat trajectory suitable for varmint hunting. With heavier bullets it is capable of taking all but the largest North American game animals; the original factory load for this is similar to the.250-3000 Savage.
Remington introduced the commercial version of this popular wildcat as a low-pressure round. At the time there were many older actions available of questionable strength. With a modern action and handloading, this cartridge is capable of markedly improved performance. One of the common improvements is called the.257 Roberts which has a SAAMI maximum pressure limit of 58,000 PSI compared to the 54,000 PSI listed for the standard.257 Roberts. P. O. Ackley said that the.257 Roberts Ackley Improved was the most useful all-around cartridge. The Ackley Improved was a typical change of a steeper shoulder coupled with blown-out sides for more of a straight cartridge, providing greater powder capacity. Data for muzzle velocity and muzzle energy is for a 24" barrel, except.250-3000 Savage, for a 22" barrel and.257 Weatherby Magnum, for a 26" barrel. 6 mm caliber Delta L problem List of rifle cartridges Table of handgun and rifle cartridges.257 Roberts at Reloaders Nest.257 Roberts at The Reload Bench
.300 Winchester Short Magnum
.300 Winchester Short Magnum is a.30 caliber rebated rim bottlenecked centerfire short magnum cartridge, introduced in 2001 by Winchester. The cartridge overall length is 72.64 mm, cartridge case is 53.34 mm in length and the bullet diameter is.308 in, common to all U. S..30 caliber cartridges. The principle at work in the short magnum cartridge is the advantage of fitting larger volumes of powder in closer proximity to the primer's flash hole, resulting in more uniform, consistent ignition..300 WSM has 80 grains H2O case capacity. The 30-06 Springfield has 69 grains of H2O, 308 Winchester 56 grains of H2O, the 30-30 Winchester at 45 grains of H2O case capacity; the 300 Winchester Magnum has Case a H2O case capacity of 93.8 grains. With this aspect of near identical performance of the 300 Winchester Magnum, the.300 WSM does this with about 14 grains less of powder behind its bullet. This demonstrates a clear superior engineered design behind the.300 WSM. The.300 WSM head spaces off its case shoulder versus the older 300 Winchester Magnum's belted head space engineered design.
The advantage to this round is the ballistics are nearly identical to the.300 Winchester Magnum, but in a lighter rifle with a shorter action burning 8 - 10% less gun powder. A disadvantage of cartridge case designs with large case head diameters lies in high bolt thrust levels exerted on the locking mechanism of the employed firearm. In small ring actions the larger chamber diameter removes more steel from the barrel tenon making it weaker radially. The.300 WSM is adequate for hunting moose, black bear, brown bear, mule deer, white-tailed deer in forests and plains where long range, flat shots are necessary. The.300 WSM is used in benchrest shooting. The.300 WSM has a standard bullet diameter of.308 or 7.62mm and takes advantage of the numerous bullet options available in that caliber. The.300 WSM is a Delta L problem cartridge, meaning it can present unexpected chambering and/or feeding problems. The Delta L problem article explains this problem in more detail. The.300 Remington Short Action Ultra Magnum has similar cartridge dimensions but is not interchangeable.
10.69 g Full Metal Jacket: 982 m/s 11.66 g Full Metal Jacket: 943 m/s.300 Remington Short Action Ultra Magnum.300 Winchester Magnum.300 Ruger Compact Magnum Winchester Short Magnum List of firearms List of rifle cartridges Table of handgun and rifle cartridges List of individual weapons of the U. S. Armed Forces 7 mm caliber Delta L problem C. I. P. TDCC datasheet 300 Win. Short Mag
The 6mm BR is a centerfire cartridge created for benchrest shooting. The cartridge is known as the 6mm Bench Rest or 6 BR, has developed a following among varmint hunters because of its efficiency. There are two basic variants of similar dimensions, known as the 6mm BR Remington and the 6mm Norma BR. Soon after the introduction of the.308 Winchester-based wildcat.308×1.5" Barnes cartridge and experimenters began developing their own wildcats based on.308 Winchester. By 1963 there were several.24 caliber cartridges based on the Barnes' cartridge. The new cartridges’ accuracy and efficiency was noticed by the bench rest shooting community. The.24 caliber cartridge version became known as the 6mm Bench Rest or the 6mm BR due to its widespread use in the sport of bench rest shooting. Because the cartridge was a wildcat and was not standardized until several years several variations of the cartridge existed. Cases required fire forming in the chamber. Several 6mm BR variants exist apart from the Remington and Norma versions: the 6mm BRX, 6mm Dasher, 6 mm BRBS 6 mm UBL.
In 1978 Remington started manufacturing their Remington 40-X rifle in the 6mm BR and named their version of the cartridge the 6mm Bench Rest Remington. By 1988 Remington was manufacturing ammunition. Remington continues to offer the 6mm BR Remington in the 40-X series rifles; the Remington version of this cartridge is now considered to be obsolete. In 1996 Norma of Sweden introduced the 6mm Norma BR, dimensionally similar to the 6mm BR Remington; however the chamber of the Norma version provided a longer throat making allowances for the seating of low drag bullets. It was designed from the beginning to optimize accuracy, barrel life, case capacity in a 6 mm cartridge for 300–600 metres target shooting; as such it couples a sensible case volume to bore area ratio with ample space for loading long slender projectiles that can provide good aerodynamic efficiency and external ballistic performance for the projectile diameter. This is the most common variation of the cartridge used today; the 6mm Norma BR has become a popular chambering in match rifles used in 300 metres ISSF and CISM and other 300 metres rifle disciplines.
The 6mm BR Remington cartridge is a.308×1.5" Barnes cartridge necked down to accommodate.243 bullets. The.308×1.5" Barnes cartridge is based on the.308 Winchester case shortened to 1.5 inches. It is one of the earlier cartridges to follow the fat design concept. Short fat cartridges have characteristics that make them more accurate; the 6mm Norma BR cartridge was introduced by Norma in 1996. It is based on the 6mm BR Remington cartridge, although where Remington's cartridge was intended for bullets of about 70 grains, Norma standardized their set of chambering specifications for a low drag bullet of over 100 grains, thus realizing the long-range capabilities of the cartridge; this required a much longer throat in rifles chambered for the Norma cartridge. List of rifle cartridges 6 mm caliber 6mmBR.com - 6mm BR Rifle Shooting and Reloading Information 6mm BR Remington page at ChuckHawks.com