Bullet Size Guide and Instructions

Early appearance of bullets were round in shape balls filled with lead which were loaded down the muzzle of smooth-bore firearms which are then propelled by the ignition of a physically separate charge of black powder. Modern era bullets consist of a cartridge case with the bullet affixed at the front end, the percussion cap or primer at the base, and the propellant powder contained within the tube (skip straight to the bullet size charts).

A bullet is defined as an elongated metal projectile that is shot from a gun barrel. Its components include copper, steel, lead, primer, and rubber. Moreover, a bullet style differs depending on its intended task, bullet caliber is shown by the diameter and weight in both metric and imperial measurements for example; a 55 grain .223 caliber bullet is of the same weight and caliber as a 3.56 gram 5.56 mm caliber bullet.

Bullets tips come in various types and designs they are;open-tip bullets, full metal jackets, soft point bullets, ballistic tips, armor-piercing cartridges, hollow point bullets and many more.

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Bullet size and ammunition sizes
Bullet size and ammunition sizes

Summary of Bullet Size Guide

Bullet Size Chart: Components of a cartridge

A cartridge is a an ammunition packaging tool designed to fit into the gun barrel. Bullets are one of the components of the cartridge others include;

Casing– can either be made of copper, brass or steel and it houses all the other components.The original cartridge case was made up of paper but nowadays they are metallic.

Primer– when the firing pin receives impact it ignites the gun powder dividing it into two types the rimfire cartridge where the primer is located in the rim and the centerfire cartridge where the primer is located at the center.

Propellant– it holds the actual power to fuel any firearm. For it to perform accurately grain size and shape influences the burn rate.

Below is a bullet size table with a few examples of matching cartridges:

Cartridge nameBullet length in inches and millimetersCase length in inches and millimetersCartridge length in inches and millimeters
.41 Short Colt0.40 inches 10.2 millimeters0.65 inches 16.5 millimeters0.91 inches 23.1 millimeters
2.7 mm Kolibri (2mm Kolibri, 2.7*9mm)0.11 inches 2.7 millimeters0.37 inches 9.4 millimeters0.43 inches 10.9 millimeters
.22 Long Rifle (.22 LR 22 Stinger)0.22 inches 5.7 millimeters0.59 inches 15.1 millimeters0.97 inches 24.8 millimeters
.22 Remington Jet (22 Centerfire Magnum)0.22 inches 5.7 millimeters1.28 inches 32.5 millimeters1.58 inches 40.1 millimeters
.256 Winchester Magnum0.25 inches 6.5 millimeters1.3 inches 33.0 millimeters1.63 inches 38.9 millimeters
25 ACP (25 Auto Colt Pistol, 6.35 Browning)0.25 inches 6.4 millimeters0.62 inches 15.7 millimeters0.91 inches 23.1 millimeters
7.62mm Tokarev (7.62*25mm)0.31 inches 7.8 millimeters0.97 inches 24.6 millimeters1.35 inches 34.3 millimeters
.32 S&W0.31 inches 7.9 millimeters0.61 inches 15.5 millimeters0.92 inches 23.4 millimeters
.32 H&R Magnum0.31 inches 7.9 millimeters1.08 inches 27.4 millimeters1.35 inches 34.3 millimeters
9mm Japanese revolver (9*22mmR Type 26)0.35 inches 8.9 millimeters0.86 inches 21.8 millimeters1.21 inches 30.7 millimeters
9mm Parabellum(9*19mm Luger, 9mm NATO)0.35 inches 9.0 millimeters0.75 inches 19.2 millimeters1.17 inches 29.7 millimeters
.38 ACP(38 Auto, 9*23mmSR0.36 inches 9.1 millimeters0.9 inches 22.9 millimeters1.28 inches 32.5 millimeters

Common bullet caliber and types available

A gun caliber is the internal diameter of a barrel in addition with the diameter of the bullet. Its measurement consists of inches and millimeters.

Moreover, the most popular caliber is the 9-millimeter measurement which has the recoil at very low proximites and its usually preferred by many guns. Other variety of calibers are; .380 ACP, 40 S&W, .45 ACP and many others.

Other firearm calibers are the shotgun caliber and rifle caliber. In addition the shotgun caliber entails of three gauges. The 12-gauge shotgun is the most popular caliber round and has a larger barrel diameter than the 20-gauge shotgun. Equally important is the word gauge is termed as bore in the UK therefore we can say “12 bore shotgun’.

Rifles are housed in a variety of calibers with the lowest measurement being 4.4 mm and the highest is 20 mm which entails the anti-tank rifle. With the development of series of rifles other calibers emerged and the most popular being the .22 long rifle which is beginner friendly and can be used by used due to its low recoil, others stated are .30-30 Winchester – which is a golden age centerfire smokeless cartridge introduced in the year 1895 and its associated with lever-action rifles, .30-06 springfield- it has an accurate kill shot living no animal alive due to its power range and popular bolt action hunting round and many more.

Below is a table illustrating the common calibers in inch and their metric equivalents:

Caliber Metric caliber in (millimeters and inches)Typical bullet diameter in inches and millimeters
1724 millimeters 0.157 inches0.172 inches 4.37 millimeters
20, 2045 millimeters 0.1969 inches0.204 inches 5.18 millimeters
2215.45 millimeters 0.2146 inches0.221 inches 5.61 millimeters
225.6 millimeters 0.2205 inches0.223 inches 5.66 millimeters
2245.7 millimeters 0.2244 inches0.224 inches 5.69 millimeters
2436 millimeters 0.2362 inches0.243 inches 6.17 millimeters
256.35 millimeters 0.25 inches0.257 inches 6.35 millimeters
266.5 millimeters 0.2559 inches0.264 inches 6.7 millimeters
276.8 millimeters 0.2677 inches0.277 inches 7.035 millimeters
2847 millimeters 0.2756 inches0.284 inches 7.213 millimeters
3087.62 millimeters 0.3 inches0.308 inches 7.82 millimeters
3117.9 millimeters 0.3110 inches0.311 inches 7.92 millimeters
3127.94 millimeters 0.3126 inches0.312 inches 7.94 millimeters
3238 millimeters 0.3149 inches0.323 inches 8.20 millimeters
3388.6 millimeters 0.3385 inches0.338 inches 8.58 millimeters
3559 millimeters 0.3543 inches0.355 inches 9.01 millimeters
3569 millimeters 0.3543 inches0.356 inches 9.04 millimeters
3579 millimeters 0.3543 inches0.357 inches 9.07 millimeters
3639 millimeters 0.3543 inches0363 inches 9.22 millimeters
3659.3 millimeters 0.3661 inches0.365 inches 9.27 millimeters
3759.5 millimeters 0.374 inches0.375 inches 9.53 millimeters
4010 millimeters 0.393 inches0.400 inches 10.16 millimeters
4410.9 millimeters 0.429 inches0.429 inches 10.89 millimeters
4511.43 millimeters 0.45 inches0.451-0.454 inches 11.46-11.53 millimeters
5012.7 millimeters 0.5 inches0.510 inches 12.95 millimeters

How to Choose the Right Bullet Size

Related: Gun Sizes

Bullet sizes are determined by measuring the diameter of the bore from one part to the opposite and its measurement is expressed in millimeters, hundredths of an inch, and thousandths of an inch, for example, a 223 caliber rifle has a smaller bore diameter compared to a 270 caliber rifle bore. Specific cartridges are manufactured to match every handgun or rifle.

The barrel stamp indicated on the firearm must always match the ammunition. Similar bore size measurement does not indicate interchangeability between different cartridges. It’s important to visit a qualified gunsmith if you are unable to locate the caliber stamp written on the firearm. The weight of a bullet becomes crucial when it impacts factors such as recoil, ballistics, and accuracy.

To know the right bullet weight for you first, you need to know what unit of measurement is used and it’s called a grain (1 pound is equal to 7000 grains). Once you can identify the weight of the bullet, then with any given load you can know if it falls on the lighter end of the heavier end of the spectrum. Therefore one can choose their favorite bullet size/caliber with the availability of bullet weight.

The best bullet size for you

Getting to match the right bullet with the gun of your choice has not been an easy task for the past years due to the increase in bullet sizes and cartridge dimensions.

Nonetheless, nowadays a lot of people use their firearms for the same reasons like sporting events, hunting purposes, or self-defense therefore one can get what fits their needs from the caliber list items.

More about Bullet Size explained (video)

Bullet Comparison | Calibers and Bullet Measurements Explained by aroseland1


Law enforcement agencies should be vigilant and educate the masses on gun maintenance and gun safety to prevent fatal injuries caused by bullets. The cranial gunshot wound is one of the deadliest firearm injuries since it is on the head therefore chances of survival are minimal.

Findings show that shootings from larger caliber firearms are considered more hazardous than smaller caliber firearms due to the wound size it leaves. Fortunately, with modern advancements, the bullet indent marker was created so that law enforcers can trace the bullet or cartridge from the weapon it was fired from.

In summary, it is important to practice gun safety wherever to protect yourself and those around you.

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Picture in this post by Velizar Ivanov on Unsplash

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