Looking at the prospect of building another AR for your collection, and not sure if you want to go with an assembled upper or build completely piecemeal? If you still have questions (or are completely new to this) you’re in the right place.
1. What is an assembled upper?
An assembled upper is an upper that comes “put together.” It should come with the upper itself, a barrel already installed, and a handguard, along with a gas system. If the barrel is threaded (which is almost always the case) it should come with either a flash hider or thread protector installed. Other parts a complete upper often comes with include a BCG, forward assist, charging handle, and ejection port cover, but make sure you read the listing before you buy because they don’t always come with these.
2. Do complete uppers come assembled?
Complete uppers come assembled; this is just another term for “assembled upper.”
3. What is a stripped upper?
A stripped upper is the upper receiver itself. This is an aluminum component that receives (hence the name) all of the other upper components, including but not limited to the barrel, handguard, gas system, charging handle, and bolt carrier group.
4. Is it better to build with an assembled or stripped upper?
There is no right way or wrong way to build an AR; it all depends on what you are looking to get out of the project.
If you want to save time and just “plug and play” parts, then an assembled upper is probably the better option.
If you want to take control over customizations and make piecemeal adjustments as you build, then going with a stripped upper is likely the best option, since nothing will be templated.
5. What is a lower?
An AR’s lower is the other receiver that is necessary to complete the build. This is the part that is actually serialized and regulated by the ATF as the “firearm” itself. As a result, an FFL transfer is required to purchase or take possession of a completed lower. With a complete AR-15 lower parts kit, the lower can be assembled and mated to a complete upper to produce a functioning rifle.
6. What is an 80% lower?
An 80% lower, also known as an 80 lower or a “ghost gun” is a lower that has not been completed yet. The channels for certain pins, the fire control group and the trigger assembly have not been milled out of the aluminum stock. For the purpose of completing an 80% lower, a jig and drill, drill press or router are necessary.
Also, there are several jurisdictions in which the purchase or possession of an 80% lower is illegal. Check with a firearms lawyer in your area before undertaking a project that involves one.
7. Do I need an FFL for an assembled upper?
Since the upper is not regulated by the ATF as a firearm, you do not need an FFL transfer to take possession of either a stripped or assembled upper.
8. If I have an upper and lower, what else do I need?
The upper and lower themselves are just the receivers that accept all of the other parts that produce a functioning rifle.
You will need all of the other upper components (that would come with a complete upper) as well as an AR-15 lower parts kit that will come with lower parts needed (like a grip and trigger assembly) as well as the pins and hardware needed to join the two.
9. Can you build an AR with an assembled upper?
You can build an AR with an assembled upper, but you will need a lower and a lower parts kit, if you don’t already have a complete AR-15 parts kit or AR-15 build kit.
10. Is there a reason to build with a short upper?
There are plenty of reasons to build with a short upper that will produce either an SBR or an ARP, or AR pistol.
Many builders choose AR15 pistol uppers because the shorter, lighter platforms are easier to conceal, lighter to carry, perform better in tight spaces, and still offer rifle firepower in a much more compact package.
Explore our collection of AR pistol uppers (and pistol braces) to learn more.
11. What’s the difference between an SBR and ARP?
Not all short uppers are intended to build an AR pistol. Some are intended to produce an SBR, or a short-barreled rifle. A short-barreled rifle is a rifle with a barrel of less than 16”, which is intended to be fired from the shoulder.
An AR pistol is an AR platform with a short barrel (usually less than 10”) but the main difference is that they are not designed to be shoulder mounted, though they can be fired with a pistol brace for extra stability.
One is considered a rifle (SBR) and the other a handgun (ARP) so different regulations apply. Get in touch with a firearms lawyer if you have any additional questions.
Here for an Assembled Upper or Want to Learn More?
Explore our collection of assembled uppers, including short uppers and AR pistol uppers, along with AR15 lower parts kits and build kits, and if you have any questions remaining before you undertake the project, get in touch with us at Sales@MCSGearup.com.