Picatinny rail – Covers, risers & how to install attachments

Feb 19, 2023

A brief but interesting history of the Picatinny rail

A Picatinny rail is an attachment-friendly rail typically found around the barrel of a rifle. The Picatinny rail dates back to 1980. It was initially designed for mounting scopes atop the gun. But the military soon realized how versatile it was. Not much later, the M16A2 and the M4 were rolled out, featuring a Picatinny rail.

Despite the M-LOK being released much later in 2014 by Magpul, the Picatinny rail is still a fan-favorite. Learn more about the differences between Picatinny and M-LOK.

M16A4 with quad Picatinny rails

M16A4 with quad Picatinny rails adopted in 1997

So why did the Picatinny rail become the standard over a weaver or M-Lok rail? Simplicity. All required to attach most scopes, flashlights, lasers, and other accessories, is an Allen key. Newer attachments even feature a quick connect system that doesn’t even require tools at all.

Picatinny rails have evolved beyond AR-15 type firearms. You can find them on rifles, shotguns, handguns, and yes, even revolvers.

The use of Picatinny rails on AR-15’s

Many AR-15s feature a Picatinny rail on the top, or both sides and the top of the rifle. Some more expensive rifles feature a quad Picatinny rail for ultimate attachment real estate.

A typical setup would be a co-witness red dot sight, along with front and back iron sights. This allows you to use your red dot sight with additional accuracy. And if the red dot fails, you can still rely on your iron sights.

The sides allow you to add extra accessories, like a laser or flashlight.

How to attach a Picatinny attachment

It’s pretty straightforward. A Picatinny rail consists of slots. Depending on the attachment, it could take one or multiple slots to attach.

One side of the Picatinny attachment will consist of a claw-type piece. The other side is similar but with a hex screw attached.

Clip-on the attachment onto the Picatinny slot where you want it. Then tighten the hex screw with an Allen key. That’s it!

Picatinny Quick-release

Picatinny quick-release adapter

There are Picatinny attachments with a quick release. Or you could buy a quick-release adapter too. These come in low profile or raised. You would attach the quick-release adapter to your Picatinny attachment, and you got a quick-release attachment!

Either way, quick-release Picatinny attachments/adapters are designed to make life easier. Imagine you’re going to the range, and you have two red dot sights you want to try and a magnified scope. It could take roughly 10 minutes in total to find the Allen key, attach it, and then untighten it, remove it, and repeat.

With a quick release, those 10 minutes would become 10 seconds.

If you only have one or two sights but multiple rifles, again, the quick-release makes sense. It will allow you to interchange attachments in a breeze.

How to mount a rifle scope on a Picatinny rail

Riflescopes attach to a Picatinny rail a bit differently than the typical red dot sight. They usually consist of two o-rings that clamp around the scope. These scope rings are traditionally screwed into the rifle’s barrel.

Does that mean you can’t use rifle scopes on AR-15 Picatinny rails? Of course not! Enter the Picatinny scope rings:

These scope rings easily attach where you want them to on your Picatinny rail. Use some precaution, though. Picatinny slots are where they are. If you tighten the o-rings around the sight first and then tighten the Picatinny adapters onto the rail, you could damage the sight.

A better approach is to attach the o-rings to the scope loosely. This will allow you to get a general idea of what Picatinny slots will be used.

Now tighten the Picatinny adapters a bit onto the rail. Now make sure your scope is positioned well. It should be as close as horizontal as you can get it. Now take turns tightening the o-rings and the Picatinny adapters. Make sure you’re not forcing something in place. Everything should fit snugly.

Take a look through the scope. Does it not feel horizontal? Loosen the o-rings a bit and adjust.

If you find that your cheek weld is not comfortable, you may want scope rings with a built-in riser. This typically lifts the scope about an inch up above the barrel.

What is the use of a Picatinny cover?

I wasn’t sure what to expect when I first heard of a Picatinny cover. Only to find out it’s as simple as it sounds. It covers a section of a Picatinny rail.

So why would you possibly want one of these, you may wonder?

Well, Picatinny rails are usually made from steel or aluminum. The edges can be pretty sharp and uncomfortable to the touch. By covering a section that you don’t use, you eliminate any possibility of injury or discomfort.

Another popular reason people use Picatinny covers is for a more comfortable grip. A horizontal hand stop allows you to cuff the front of the rifle. This approach is somewhat rare, but some individuals swear by it.

The bottom of the rail would feature a small horizontal or angled hand stop. You would hold this hand stop in the palm of your hand. The thumb and remaining fingers would then grip around the barrel of the rifle. You could, of course, go foregrip-less and cuff the barrel as is.

If you want to take this approach, you’ll enjoy it much more with rail covers.

The use of Picatinny rails and slots on handguns

Picatinny slots have become more popular over recent years on handguns. While most handguns offer a 1 or 2 Picatinny slot, that’s still enough to attach an array of laser attachments.

While handgun-friendly lasers have been around for years, traditionally, they were costly as they were built to be gun-specific.

More advanced handguns can offer a Picatinny top rail that allows you to attach various scopes quickly. That includes custom iron sights, red dot sight, or even a magnified scope.

Can you install a Picatinny rail if your firearm doesn’t have one?

The short answer, yes, you can! How easy, though, depends on your rifle.

Existing M-Lok rail

If your AR-15 or other firearm offers an M-Lok rail, and you want the benefits Picatinny offers, there’s a simple solution.

M-Lok Picatinny rail sections. These sections are available in a wide array of slots, typically ranging from 3 to 13 slots.

The (small) con of this approach is that the Picatinny rail section sits on top of the M-Lok rail. This is more of a “not so pretty” con than anything else.

No existing rail

Some rifles offer pre-tapped drill holes that you can install a Picatinny rail on, like the Savage Axis/Edge rifles.

Installing a Picatinny rail this way is pretty straightforward. But there’s a crucial part most people overlook: don’t rely on just screws. Use an adhesive like Loctite.

You have to remember that every gun undergoes an incredible amount of shock and vibration when firing rounds.

Those tiny screws will eventually loosen over time, even more so if you go out and shoot hundreds of rounds at a time.

An adhesive like Loctite will help to keep everything tight. A more permanent adhesive is Flexbar Rocksett.

A bit more about Rocksett adhesive

This engineering adhesive sets in 15 minutes, as long as you can heat the parts to 175 Fahrenheit.

This is pretty easy to achieve by using a heat-gun. If you don’t have a heat gun, you could try holding it in front of a portable heater, like infra-red. Steel stores heat very well, and 175 degrees isn’t that much.

If you don’t want to or can’t heat the barrel, you can let it air-dry, although that could take hours, and it may never bond as well.

Once set, Flexbar Rocksett glue can withstand temperatures from minus 350 degrees to 2,015 degrees Fahrenheit. Keep in mind that Rocksett is typically used for permanent bonds. So think twice before applying.