AR10 vs AR15 Parts Compatibility

Calling all AR fans — if you’re a builder like us, you’re probably constantly thinking about the next rifle setup you’ve got in your mind, a clone, or when you’ll finally be able to finish that SR-25 inspired build. If this sounds relatable at all you’ll be happy to learn about all the AR15 and AR10 parts that are compatible with each other. But of course, some parts’ compatibility do not cross over between the two platforms. So today we’re getting down to the nitty gritty of AR-15 vs AR-10 parts compatibility.

AR-10 vs AR-15

For key differences between these two types of rifles check out our previous blog on that — AR-10 vs AR15: What’s the difference? Even though these all fall under the category of “intermediate cartridges,” the main differences between these two types of rifles involve which specific calibers they can support. Caliber compatibility is not interchangeable across the AR10 and AR15.

AR 10 Calibers

These are some of the most widely used calibers with the AR 10 platform:

• .243 Win
• .308 Win
• 7.62 x 51 NATO
• 6.5 Creedmoor
• .338 Federal
• 7mm-08 Remington
• .358 Win
• .500 Auto Max

AR 15 Calibers

These are some of the most widely used calibers with the AR 15 platform:

• .22 LR
• .223 Remington
• 5.56 NATO
• 6.8 SPC
• 300 Whisper
• 300 Blackout
• 6.5 Grendel
• .450 Bushmaster
• .458 Socom
• .50 Beowulf

Specifications

Specifications are important because at a glance it can be easy to mistake an AR-10 for an AR-15 due to the wide array of parts that they can share. If you can appreciate details and it helps you remember, these are these things to look out for to help you differentiate AR10s from AR15s:

Size & Weight

One might expect the AR10 to always be larger and heavier than an AR15 but that may not always be true. While the lower receiver is certainly larger, longer and heavier due to its need to receive a larger magazine with larger caliber bullets, that's not necessarily something you can discern even a short distance away. In most cases, you’d have to be looking at the rifle up close or physically holding it yourself to really be able to tell.

Barrel Length

Barrel length greatly contributes to the perceived image of a rifle’s “size” because most AR15s are sold with barrels at a default length of 16”. Anything shorter than that would be AR pistol or SBR territory which for some can be a legal concern. With the AR10s, the length is going to depend on which caliber you are using. For example, .308 WIN is often used and chambered in 18” barrels because that’s how long the caliber needs as a runway to most effectively burn up all the powder in the barrel and stabilize the projectile before it exits.

Thing is, .308 AR 10s can be had in 16” length barrels as well. So barrel length is not a good visual determiner for whether or not a rifle is an AR 10 or AR15. They’re also not always chambered in only 308 WIN. However, the most common lengths for AR 10 barrels tend to be either 18” or 20” in length. To be sure you can look for the caliber marking which is almost always etched somewhere into the barrel.

Ballistics

The AR15 has a wide variety of ammunition types that shooters can take advantage of. From varmint rounds to intermediate rifle cartridges, even big bore rounds for hunting large game. If built out well with quality parts, the AR 15 really can do it all. However, the clear limitation in even the best AR 15 calibers would be long distance and precision shooting when engaging targets at 500 yards or further.

Personally, I struggle already at the 300 - 350 mark. That’s really where the AR 10 comes in. With AR 10 calibers, you get higher bullet velocity which translates to higher energy delivered on impact and that also means a more stabilized bullet for a flatter flight path. To paint a clear picture, the 6.5 Creedmoor is now most commonly used as the go-to caliber for 1000 yard matches. If it helps, see Hornady’s Ballistics Data Tables for all the ammunition they manufacture to see how a wide variety of calibers perform up to 500 yards.

Upper Receiver Compatibility

Some AR-15 upper receiver parts are compatible with the AR-10, but most are not compatible. See the ar-15 vs ar-10 parts compatibility table below for upper receivers:

Lower Receiver Compatibility

Most parts inside the AR-15 lower receiver are compatible with the AR-10, but there are a few that won’t fit in an AR-10 lower receiver. Please note that all the 80% AR10 lower receivers we sell are technically DPMS style Gen 1. See the ar 15 vs ar 10 parts compatibility table below for lower receivers:

Start Your AR-10 or AR-15 Build with 80% Arms Today!

Now that you’re an expert in AR 10 parts compatibility with AR 15 rifles, browse our AR-10 80% lower receivers and AR-15 80% lower receivers to get started on your next build today! We have all the parts & accessories you need to be able to complete your build from muzzle to butt stock and if you have any questions - just let our legendary customer service team know, and they’ll be happy to assist you along your building process. Live free, friends.