For many hunters like myself, rimfire ammunition is used nearly as often as centerfire ammunition. I do a great deal of hunting with my .22 long rifle, and rely on it for most small game. However, you really have to look at the design and operation of rimfire vs centerfire ammunition to determine which one is a better round. I will outline those differences between centerfire and rimfire, so you can choose the round that perfectly fits your needs.
For many people the first rifle they ever fire is a .22 long rifle. The .22 round was the first rimfire round ever created, and the design is basically the same as it was in 1845. The rimfire was the first self-contained cartridge ever manufactured and opened up a whole new world for gun owners.
For those that are not familiar, the rimfire works by inserting a bead of primer around the circumference of the rim at the base of the cartridge. When you fire a rimfire cartridge, the hammer strikes the rim of the casing which sends the bullet in motion. The very first rimfire rounds were created in France. They actually had no powder, so the primer bead itself was the driving force for the bullet. It was a very weak round intended for indoor shooting for fun.
In 1857, powder was added to the .22 rimfire round giving it much more power and versatility. A .22 revolver was created and many soldiers carried one in their pocket as a backup weapon in the field. Rimfire continued to dominate the market until around 1870. Then came the start of the rimfire vs centerfire argument.
The difference with centerfire ammunition is the use of a self-contained primer inserted in the rear of the round. The use of fulminated mercury based primers to ignite cartridges allowed for rounds to have significantly more power. Larger bullets could be used with more powder giving weapons much more functionality for hunting and defense.
When the self-contained primer was first invented it actually created a design problem for manufacturers. Suddenly they had the ability to stuff a great deal of fire power into a cartridge, but the metal of the cartridge was not strong enough to contain this power. It took some time for them to improve the metallurgy and optimize the potential of the centerfire round.
The centerfire round allowed for shotguns to be quickly reloaded for hunters. Soldiers now had rifles that could reach targets at greater distances, impact with greater power, and sight in with surgical accuracy. Gun manufacturers now how all kinds of new design opportunities that could be used with the centerfire ammunition.
Design Comparison Rimfire Vs Centerfire
When looking at the design and function of centerfire vs rimfire ammunition, it is hard to deny that centerfire has an edge. There is a reason why almost every modern round is made centerfire.
The first design improvement in the centerfire round is a more even burn to the powder. When you hit the primer bead on a rimfire round, powder on one side of the round may be burning a bit faster than on the other side. This uneven burn greatly reduces the amount of powder you can use in a round. The centerfire round is struck in the middle creating a completely even burn.
The next improvement is that centerfire rounds can be made with thicker cartridges. One of the design flaws of the rimfire is that you actually have to strike the edge of the cartridge for it to fire. This weakens the cartridge wall, and forces you to use thin enough material that the strike will ignite the primer bead. On a centerfire round the primer is removable and is the only piece to be struck. This means that you can make the cartridge walls as thick as you like allowing more powder and larger bullets.
The last design benefit of the centerfire round is the fact that the cartridge is left intact after being fired. Because the primer is self-contained and removable, the cartridge can be reused. If you have a press and the other tools needed to reload your rounds, you can save your cartridges and use them over and over.
Firearm Design and Function
When reviewing the debate for rimfire versus centerfire ammunition, you must consider more than just the design implications. You must also consider the relationship between the round, the gun, and the user. There are several ways that different ammunition types can enhance or limit the user’s experience.
The first difference to consider between these rounds is reliability. Because centerfire rounds have a separate self-contained primer designed for only one function, they are much more reliable. The fact that the primer bead is built into the casing on a rimfire round makes it more prone to manufacturing flaws. This could cause misfires in these rounds. That is why more people use rimfire rounds for hunting or practice, and more people use centerfire rounds for self-defense or military functions. When it absolutely must fire every time, people go with centerfire rounds.
The next is accuracy. On one hand you could consider the rimfire round to be more accurate because it creates less recoil. Recoil can cause accuracy issues for a few reasons. One is that anticipating recoil can cause people to flinch just as they are firing. Recoil also makes second or third shots less accurate as the force pulls your barrel off target and you have to line up your sights again. The lack of recoil in a rimfire virtually eliminates these issues.
On the other hand, the lack of power and light bullet weight can make long distance shots more difficult. A round with less powder will travel at a slower speed and therefore will drop more over long distances. In addition, lighter bullets can be greatly affected by a crosswind. If taking shots of 100 yards or more, you can easily see winds push a bullet six inches or more. Therefore, rimfire rounds are better for shorter distances. For longer distances, the centerfire round is a better option.
The last difference to consider is how the different rounds affect the design of the gun itself. On single shot guns there is no difference in reloading. However, there is a huge difference in semi-automatic weapons. Centerfire rifles use the force generated from escaping gasses to reload the round. Rimfire guns actually use the small amount of recoil created by the round to reload. This actually makes rimfire guns much less complex, and often simple is best.
The other change in firearm design is related to the shape of a rimfire cartridge. The rim itself creates some challenges with feeding the round from the magazine to the chamber. Gun manufacturers have been forced to be creative to solve these problems. This can be seen in the Ruger’s rotary magazine and the extreme curvature of the Ruger BX25 magazine.
Differences between Centerfire and Rimfire For Hunting
When considering rounds for hunting, there are several pros and cons for centerfire vs rimfire ammunition. For small game, rimfire is considered king. The inexpensive rounds and the lack of recoil make them ideal for rabbits and squirrels. If you are just looking to put meat on the table, you really cannot beat a rimfire .22 round.
The real argument comes into play when you consider larger game. Some people claim that they can hunt larger animals with rimfire ammunition. While it is true that a perfectly placed shot with a rimfire round can take down almost any animal, the odds of success are not great. I have debated this topic myself. If you want to be a responsible hunter, you really should save your rimfire rounds for small game.
The other variable you must consider is the quality of the bullet. Most rimfire bullets are made with softer metals designed to fracture and spread once impact is made. This works fine for smaller game, but it is not ideal for the thick hides of larger animals.
There are centerfire rounds that can be used for small game, but they tend to be much more expensive than rimfire rounds. However, when it comes to large game you cannot beat centerfire rounds. They give you the power, bullet speed, and accuracy you need to take down the largest animals. Also, when you are taking a shot at a large animal that you have been stalking for days the reliability of centerfire ammunition is comforting.
When looking at the comparison between rimfire vs centerfire ammunition, we feel that centerfire is a better round. While I use both types of ammunition on a regular basis, centerfire is obviously the superior design. It is reliable, accurate, powerful, and reloadable. It is good for self-defense, military applications, big game hunting, and small game hunting. While the rounds are a bit more expensive, the ability to reload the cartridges more than makes up for the cost difference. Both rounds definitely serve their purpose, but I do find centerfire rounds to be more versatile.