Skip to main content

Calibers of the Semiautomatic Handgun, The .45 Caliber

Eric J. Perry is a former firearms instructor for various police departments. He is an Army veteran.

About 45 ACP

This is the second installment of the 5-part series, Calibers of the Semiautomatic Handgun. This part will highlight the famous .45 caliber. The first part covered the .40 caliber. For the record, I am not endorsing the purchase of any brand, make, style, of firearm, ammunition, or accessories, nor am I endorsing purchasing any firearm, ammunition, or accessories from any vendor. I do not have any sponsors. I am writing this as general information for someone that may be interested in purchasing a firearm and does not know where to begin. I use my personal and practical experience, and in doing so I only speak about the equipment either I have used, officers I have trained used, or colleagues have used and we shared experiences. I want you to understand where I am coming from, and that I know the process of having so many options to choose from can be overwhelming. I was there. I had to purchase my duty firearm when I entered law enforcement because the department was too small to provide one for me. I had heard all the chatter about various manufacturers, calibers, ammo, and everything else. I couldn’t take their word for it. I had to find out for myself because my life would literally depend on it.

My approach is intended for the first-time buyer that is looking for the right pistol that is a perfect fit for him or her, but I believe that this can be useful information for anyone. In this series, we will discuss ballistics, costs, availability, history, and my personal experience with the various calibers. My desire is that after reading this series is that you--the potential buyer identifies the best caliber for what you need. This is about you. You will be investing a nice amount of money into a pistol and the ammo, so make sure it’s what you like and need and not what a magazine tells you to like. Ultimately, you will need to find out for yourself. Do your own research, shoot several kinds, and consider that your life may depend on it. That should help you make a good decision, but I pray, in the name of Jesus, that none of you will be in that situation. Enjoy the read and thank you.


The .45 Caliber

Every caliber has its purpose and its fan base. Just like cars, trucks, and sports teams there are people out there that love one and hate the other, or think one is terrible and the other is great. This is the reason there are so many options to choose from. I don’t know anyone that does not like the .45 caliber. I don’t prefer it, and rarely recommend it, but I don’t dislike it. I prefer the .40 caliber. I know people that hate the .40 and wouldn’t carry anything other than a .45. That’s the great thing about choice. Just remember when it comes to all the varieties of rounds out there, no one is wrong and no one is right. Everyone must choose what is best for themselves.

The intent of this 5-part series is to assist you on your journey in determining which round suits you best. In the first 4 parts of the series, I will provide a breakdown of the most common cartridges in use today, and the last part will be to discuss some of the lesser common cartridges in circulation. This is not an all-inclusive discussion of each round, but rather an overview. If you feel you need more specifics before deciding, then I highly recommend further research. You will be more accurate, more willing to practice, and buy more ammunition when you find the pistol that you really love. My desire is to get you heading down that right path.

In this part, we will discuss the history, ballistics, cost and availability, and my personal experience and considerations in choosing the .45 caliber cartridge. I will discuss the various makers of semiautomatic firearms in another article. This article is specifically intended to discuss calibers. In my opinion, ammunition is more important than a firearm. Most malfunctions with a semiautomatic pistol are due to the ammunition. There are dozens of high-quality firearm manufacturers out there, but you only need to buy the pistol once. The ammunition must be continually replaced during use, and the caliber you choose will determine the price, availability, comfort, and control of the firearm you chose.

Glock 21SF .45 ACP

Glock 21SF .45 ACP

Experience and Considerations

This is not the handgun for the small of hands. I truly do not have any intentions in offending you, but if you have small hands you may want to consider a different caliber or explore custom grips or single stacked handguns. A single stacked magazine like in the 1911 model pistols allow for a narrower grip at the cost of smaller magazine capacity. I am not trying to scare you away from the .45 caliber. I want to make sure nothing is left unsaid. This is a large investment and I want you to make the most informed decision you can.

The investigators at my department, and the Sheriff’s office carried subcompact Glock .45s. They were issued these by the department with the intent of concealment, and maximum firepower. They achieved that goal, but they didn’t consider the difficulty of qualifying with a subcompact 45. Whatever firearm a police officer carries, he must be able to qualify with it. That’s logical. The qualification course for the investigators and their subcompact pistol was the same as for the patrol officers with full-sized pistols. Every person I trained that had a subcompact had difficulties or failed to hit the target at 25 yards. The .45 has a lot of kick to it, and a subcompact is very small and doesn’t allow you to obtain a solid grip, especially compared to a full-framed version. Very few people will need to take a shot from 25 yards with a subcompact, but if you do you better have trained extensively with that pistol before you squeeze the trigger. Bottom-line, you will have to practice more if you choose this large caliber with a small-framed pistol, but it can be done.

The .45 has kick to it. Just like the .40 caliber, you will have to spend time practicing. I recommend that with any firearm, anyway. I wouldn’t let this be my teenage daughter’s starter gun. Settle down, of course I know she could handle it, but there is an intimidation factor with this caliber. So, check your pride, and get what will be the most effective in whoever’s hands you put it in. Pride won’t matter much if your one opportunity misses, and you aren’t around to see your family cry for you. Hard truths. The .45 is a solid, dependable, time-tested firearm, but it is not for everyone. My brother’s hand won’t support the full-framed good enough so he got rid of his. I prefer a .40 caliber because I can shoot it better. Everyone is different. Find what fits.


The .45 caliber can claim the spot as one of the oldest semiautomatic calibers in circulation. The .45 caliber has been a household name for over a century. It has over 80 years of military service and is one of the most popular calibers among law enforcement in the U.S. The U.S. Cavalry was searching for a new caliber pistol that had stopping power the military needed. They tasked Colt with this mission. Colt was already working on a .41 caliber cartridge for the Cavalry so they expanded it to .45. After a few years of trial and error, John Browning developed the round for Colt. The pistol became known as the Colt Model 1911, named for the year the military adopted it. The Colt 1911 remained in military service until its replacement in 1985 by the 9mm. Although the .45 is no longer used in the military, except with some special operations units; it is one of the more common choices among law enforcement.


Ballistics of a .45 Caliber

In this section, we will talk about ballistics of the .45 caliber cartridge. My intent is to simplify this so that every reader can understand the basics of how ballistics work and vary among various calibers. There are numerous variations of the round such as hollow point and full metal jacket (FMJ) with even more manufacturers. The grain of the cartridge also plays a factor in ballistics. For example, a hollow point would have less penetration than an FMJ but would have more force at the point of impact (the knock-down power we've always heard about). Also, the grain of powder in the cartridge would affect penetration by having a higher velocity (speed) of the round.

The .45 caliber has unparalleled stopping power. The recoil (kickback felt in the hand from firing) is powerful, but the impact (the force hitting the target) is even more impressive. No one on this planet wants to be on the receiving end of a .45 caliber. As you can see in the chart above, the round makes a large opening. This produces force of impact and can cause the target to be knocked back or down. The speed of the round and the size are primarily the factors in this “knockdown power” as most everyone has heard before, but may not know what it means. In comparison, the smaller 9mm round moves at such a speed (velocity) that it can move through a target without checking up and exit before the round fully expands. That is why you hear stories of people being shot with a 9mm and still standing. It doesn’t happen often, and the injury will soon take effect, but that happens even less with a .45 caliber round. The offset to that is that at further distances such as 25 meters and beyond the round will drop from the aim point. Most people don’t have to worry about shooting that distance though.

One of the major factors regarding velocity is how much the round will slow down at a greater distance from the barrel and the effect of gravity on the round. The greater the distance the round travels it slows down and begins a downward slope. This means at longer ranges the round will hit lower on the target than where you aimed. The .45 caliber’s average velocity of 700-1150fps (feet per second) compared to the average velocity of a .40 caliber round is 900-1450fps. A benefit of the slower round is the consideration of what is behind the target. For example, a .40 caliber or 9mm round can go through a body and keep going on the other side if it does not hit bone, and very few people in that kind of situation are aware of what is behind the target. The same can be said for a target miss in a house and the round impacts an inside wall which usually does not have insulation. The .40 caliber or 9mm will most likely go into the next room unless it hits a stud. There are countless bad scenarios when considering that. The .45 is a lesser liability with these considerations, because of the speed of the round. It makes a nasty impact and then stops. The penetration of the .40 caliber round ranges from 9.8”-27” compared to a .45 caliber round that has a penetration of 11.3”-27”. The depth of penetration varies so greatly based on the type of round and the grain of the cartridge, but as you can see, in general, the .45 does have deeper penetration.

Good round to keep in your pistol for carry.

Good round to keep in your pistol for carry.

Good round to use for practice. About half the price as the Hornady.

Good round to use for practice. About half the price as the Hornady.

Cost and Availability

The .45 caliber handgun and ammunition generally cost more than that of a .40 caliber or 9mm. I posted pictures of 2 brands that can be found at Wal-Mart or any guns and ammo store or online. They are very common and I have personally fired both brands. There are numerous manufacturers of .45 ammo, so finding it should not be a problem. Price does vary, depending on the quality. For example, the hollow-point Hornady cost about $1 per round. The CCI Blazer FMJ (Full Metal Jacket) cost around 50 cents per round. I would practice with the FMJ and carry the hollow-points. make sure you do fire the hollow-points you carry so you can practice with what you carry. They do and will fire and impact differently. The grain of powder and weight of the bullet affects velocity and point of impact. In general, the cost and availability of this round is very good. This, most likely, will not be an issue or major consideration in deciding on this caliber.

Closing Thoughts

The .45 caliber is a very impressive round with a long rich history. This caliber is not fading away anytime soon so availability should not be much of an issue. I would call this caliber and this firearm, "Old Faithful". I prefer the .40 caliber, but I give the .45 high marks. The biggest concern I see with this caliber is whether the pistol you purchase will fit in your hand properly. Buying a pistol is a big purchase and a great responsibility. Do yourself a favor and hold out for the right one. You will feel more comfortable, practice more, and shoot better if you do. Whatever you choose, I pray you never have to use it, and I pray that if you do you learned how. God bless you and all of your family. Thank you for reading.

What is Your Favorite Caliber?

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2017 ericjperry


ericjperry (author) from Cullman, AL on June 09, 2017:

Got it. Thank you.

Jack Burton from The Midwest on June 09, 2017:

minor typo right under "ballistics" heading