How To Read Colt Serial Numbers

Serial numbers on Colts can provide owners and buyers with prospective information regarding the date of manufacture and barrel length, caliber, and material used for the finish.

Colt uses a series of numbers and letters in the serial numbers, each denoting a different aspect of the firearm, but knowing what each prefix, numeral, and suffix means can be confusing for first-time serial number readers and even experienced Colt owners alike.

Aside from figuring it out yourself, Colt provides both an online channel and a more reliable method to determine the genesis of Colt firearms with great certainty, so let’s look at the ways to read Colt Serial numbers.

How To Read Colt Serial Numbers

Colt Serial Numbers: Prefixes, Numerals, And Suffixes

While this may sound like a spell out of Harry Potter, Colt has long used this system for classifying their guns, so let’s look at each element and gain a better understanding of each and what they mean.

How To Read Colt Serial Numbers: The Prefixes & Suffixes

More often than not, the prefix & suffix codes are simply abbreviations of the model name of the firearm, so where you see the prefix or suffix ‘SA,’ for example, this denotes Single Action. The ‘NF’ code denotes New Frontier, ‘SP’ is the prefix or suffix for ‘Sporter,’ and ‘MT’ is the ‘Match Target’ prefix or suffix code.

 The prefix ‘C’ stands for Commercial, and here is where the Colt serial number sequencing can get confusing as sometimes the letters can be used to denote the year of manufacture of the weapon.

A sure way to read your Colt’s serial number is to get the firearm reference table, and you can then match your serial number accordingly.

The Colt Firearm Model Codes

Colt uses a series of numbers that denote more details about the gun in question like the type of frame, caliber, barrel length, and finish used on that specific gun. For example, we’ll look at the gun that won the West – the Colt Single Action Army.

The first number represents the model’s frame type. If the number is a ‘1’, this would indicate the standard frame for that model, while a ‘2’, ‘3’ or ‘4’ denote later variants of the gun.

In this case, the number ‘3’ indicates a non-standard frame, while the number ‘2’ would indicate that the frame came from the Colt Custom Shop. Now that you know the frame type, we can move on to the second number, which would indicate the caliber of the firearm.

Colt Serial Numbers – What The Caliber Numbers Mean

The second number in the sequence is the code for the caliber of the gun, and these run from the number ‘4’ to the number ‘9’. The number ‘4’ indicates a caliber between .20 and .32.

The number ‘6’ would denote a caliber of .357; there is no number ‘5’ in this caliber identification sequence.

If the number is a ‘7’, this will denote a caliber of .44, the number ‘8’ would represent a .45 caliber, and the number ‘9’ would denote a caliber of .40 to .44.

So, if your SAA has a serial number starting with SA17, this would tell you that your gun is Single Action with a standard frame and in .44 caliber.

Colt Serial Numbers – What The Barrel Length Numbers Mean

The third number in the four-digit sequence refers to the gun’s barrel length, and here, things can get a little confusing. You would think that the number ‘1’ would represent the shortest barrel, but no, it’s the longest at 12″.

In this numerical description, there is no number’ 6,’ so the barrel lengths start with the number ‘3’, which is 3 -4 inches.

The number ‘4’ is for a barrel length of 4.75″ or 5″.

The number ‘5’ for lengths of 5.5″ and then number ‘7’ shows a length of 7.5,” and the number ‘1’ is for a barrel length of 12″.

So, coming back to our imaginary serial number, the SA177 would indicate the SAA has a 7.5″ barrel length.

Colt Serial Numbers: What The Material Finish Numbers Mean

The fourth number in the sequence indicates the type of material used for the finish, and these numbers run from 1 to 6, but with no number 5 in the reference. Nickel finishes are commonplace with Colts, so almost every number in this position indicates nickel except the number ‘6’.

The number ‘1’ indicates a nickel or pure blue finish.

The number ‘2’ would denote a nickel or blue case-hardened finish

The number ‘3’ shows that the finish was a plain nickel.

The Number ‘4’ denotes a Royal Blue case-hardened finish, and the number ‘6’ is a nickel finish. This fourth number is often used to differentiate between older and newer models.

Completing our imaginary serial number SA 1774 would show a 7.5″ Single Action in .44 caliber with a Royal Blue case-hardened finish.

As you can see, using and interpreting the serial number on your Colt could lead to some uncertainty. Still, fortunately, Colt provides less frustrating and more manageable ways to find out more about your gun.

The Serial Number Lookup

How To Read Colt Serial Numbers – The Serial Number Lookup

In this digital world, Colt has made it easy for you to source information about your Colt firearm simply by going to their website here and entering your serial number in the search box.

If you don’t have the inclination to do the manual research yourself, head to the Colt website and punch in the serial number, wait a few seconds, and you will get direct feedback from Colt.

It should be noted that the information you would receive here would be approximate only, and Colt state that on the page; so if you are looking to assess the potential value of your Colt, then you should take the next step by requesting a Letter Of Authenticity from Colt.

Reading Colt Serial Numbers – The Letter Of Authenticity

This route will cost you anywhere from $100 or more, but you are guaranteed to have far greater peace of mind regarding your gun using this method.

Using the page here, you can request an LOA for your firearm, and if you have found one in a yard sale or bought it at auction, the LOA is an excellent addition for your firearm to establish its value and origins without any fear of contradiction.

Prices for the LOA will depend on the guns themselves, and here is a list of prices for the LOA based on the gun in question.

Gun Model TypePrice ($)
Percussion Models$200 – $300
Revolvers$75 -$100
Pistols$75 -$100
Rifles$75 -$100

This process will take about 90 days to complete, and you would need to pay for it upfront. The good news here is that if you have multiple firearms to verify, you will get discounts of up to 20% for 20 inquiries or more.


For Colt lovers, knowing as much about your beloved gun as you can add to the joy of owning them, and it’s a story to tell around the campfire with your hunting buddies.

Whether you elect to do the research work yourself or use the more straightforward options like the online search or go for the LOA, you will come out with newfound insight and appreciation for what is undoubtedly some of the world’s greatest guns.