What is “Mil-Spec”?

Milspec is one of those words that gets thrown around a lot in the gun community. When you are researching AR15 parts or reading up on them, you will see milspec pop up again and again.

But what exactly does it mean?

Not a lot of people seem to know and if they do, they have a skewed idea of what being milspec actually is. It’s time to shed a bit of clarification on the topic and probably step on some die-hard toes. Sorry.

What is “Mil-Spec”?
Photo by Moto “Club4AG” Miwa

What is Milspec?

Well, it is exactly what it sounds like. Military specification. This is the set standard for military issued weapons and gear.

However, we will be focusing on the small section regarding rifles, mainly the M4, M16, AR15, or whatever you want to refer to them as. The U.S. government and military require that all issued weapons meet a minimum standard.

The guidelines consist of fire rate, materials used, dimensions of parts, weight, finishes, etc. Simple enough and it makes sense. They protect the American freedom!

However, milspec really doesn’t do more than ensure that guns function, last, and that parts are compatible.

What’s the Problem?

There isn’t necessarily a problem, more so, a misunderstanding. The military obviously needs weapons that meet their requirements, so they can do their job.

The problem is that the idea of milspec leaks into American gun owners. Again, it’s not a problem, but people seem to misunderstand what exactly milspec is.

milspec problem
Photo by Moto “Club4AG” Miwa

Everyone has their own idea of the word and what it means. There are lots of fanboys and people who write off and criticize anything that isn’t milspec for their AR15. The irony of their closed-mindedness is that the AR15 is not and never will be 100% milspec

The AR15 is the civilian version of the military’s M4/M16. Those two rifles meet required standards and have a select fire. Select fire gives you the option for burst or fully automatic.

Not something that normal people have access to. If don’t have the select fire capability, your rifle is not milspec. If you do, I hope you have the extensive training and certification to make it legal.Nonetheless, it is completely possible to get the same quality parts from milspec manufacturers.

For example, most civilian AR15 barrels  are made by FN, who supplies a huge portion of the military with their rifle barrels.

However, they will not have been approved or tested by the government, which technically makes them non-milspec. Despite them being non-milspec, they are still just as good as a military issued barrel, but without the milspec tag.

Narrowing it down.

My main point is for people to stop focusing on the idea of milspec. You can’t have it and you’re missing out on a lot of great options by chasing it.

Sure, you can buy worse than milspec and feel like you got burned, but you can also buy better than milspec and win!

The reality is that milspec is another minimum standard that is mandated by the government. Typically, these are given to the lowest bidder and they aren’t shooting for competition level guns. They just need to know that they will work.

Why would you limit yourself to the same minimum requirements when you can have better parts?

I’m not bashing the military or their gear. They do what they do better than anyone else in the world and they need to have a balance of standards and cost. However, we civilians don’t have to live by these standards and can deviate from them.


milspec deviate

Yes, deviate from the standard. What a crazy idea!

Now I wouldn’t recommend getting parts that are below milspec because they will most likely break, but look at your options.

For example, there is a relatively new phenomenon with bolt carrier groups (BCG’s) being made out of nickel boron or chrome. They are incredibly easy to clean and don’t need to be lubricated because the nickel is self-lubricating.

They are nowhere near being milspec, but guess what? They are just as durable as any milspec BCG and work fantastically. They even add a little bling to your gun, if you’re into that sort of thing.

They got it right!

Now, hold off on chucking your guns in the river for one more minute. There are plenty of milspec things that every rifle should have.

M4 feed ramps? Not at all required, but they do make your life at the range jam-free!  No you don’t need a select-fire lower receiver or BCG made of carpenter 158 steel because there are other options.

But you should at least make sure your gun is staked, mainly the gas key. This is an important part to making sure your AR15 doesn’t become a single shot rifle when the key comes loose.

Another milspec standard that you should follow is making sure your BCG is HPT/MPI tested. This ensures that there aren’t invisible cracks and that it can withstand the pressure of being fired.

These are just personal suggestions and you should figure out what you want for your rifle.

Reeling it in.

milspec feel it
Photo by Erich Iveans

Everyone has their own opinion when it comes milspec and everyone else’s is wrong. That is just the way it is and that’s fine.

But my advice is that you should not limit yourself by focusing so much on milspec. Instead, do your own research on both the products and companies selling them.

You will find there are “milspec” parts that are garbage and you will find non-milspec parts that are amazing. It all depends on the company and the amount of effort that they put into their products, so do yourself a favor and remember this advice, while you research what you want.

Leave a Comment