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Montana 80 Percent Lower Laws

80 Percent Arms   |   Jan 11th 2022

Disclaimer: To get started, we want to share a small disclaimer. We are dedicated and proud supporters of everything 2nd amendment, but we are not lawyers. So, before you take what you read here and run with it, you will want to double-check all of your local or state gun laws. Make sure you are up to date on any special regulations that may apply to you and your situation. Gun laws are always changing and always do your part to stay up to date with the newest and current laws.

This information is provided as a service to the public. It is NOT intended to be taken as legal advice and should never be considered as such. Make sure to do your own research as you and you alone are responsible for your own actions.

This is a developing list of information we intend to update regularly to stay accurate and current. If you see a discrepancy or a mistake with your home state’s laws that we’ve covered, feel free to let us know so we can correct it. Thank you and stay safe!

What is an 80% Lower?

An 80% lower receiver is an unfinished and unserialized blank which requires some machining work from the end user to turn it into a 100% lower receiver, otherwise, what is legally considered as a firearm. 80 lowers are missing the trigger pocket and three holes that need to be milled and drilled out to be completed. Unless states have passed their own laws barring the possession or sales of 80% products; pending the ATF's updated decision from the most recent proposed rule 2021R-05 80% lowers are completely legal, not considered firearms and thus can be shipped straight to your front door. No FFL required. To explore the 80% lower receiver products we have to offer, check out our multiple collections.

Are 80 Lowers Legal In Montana?

As of this guide’s initial publish date, 80% lower receivers and frames are not considered as firearms by the ATF and are legal to ship directly to buyers residing in the state of Montana.

Do I Need to Serialize My 80 Lower in Montana?

If you build out your own firearms starting with 80 lowers in Montana you do not need to serialize the lower receiver or frame as there are currently no laws requiring citizens to do so. Should you wish to serialize your lower receiver you certainly can if necessary through our 80 lower engraving services.

Key Gun Laws in Montana

Other than laws regarding 80 lowers, these are the key gun laws you should be aware of if you reside or are traveling through Montana.

Firearm Possession and Purchase Requirements

Montana is one of a few states that doesn’t impose any specific age restrictions on the purchase or possession of firearms due to a strong gun culture so most federal laws will kick in to determine certain policies. No extra permits or licenses are necessary to purchase long guns or handguns in Montana. However, due to Montana’s child access prevention law, minors under the age of 14 aren’t allowed to carry or use firearms in public. Since the regular federal age restrictions apply it means that legal buyers must be 18 years of age to buy a long gun and handgun buyers must be at least 21 years old. The normal exceptions for minors in possession of firearms apply as well which include when attending a hunter’s or firearms safety course, using the gun for target practice or recreational shooting at an established range, involved in an organized competition, hunting or trapping with a valid license, traveling to and from these events, or at their own residence with permission and supervision of a parents or a legal guardian.

Firearm purchases generally require a background check but private party transfers do not (Dealer Record of Sale also known as 4473 form or “DROS”). While federal law requires federal firearm license holders (“FFL’s”:) to initiate background checks on buyers prior to the sale of a firearm, federal law also allows states to serve as their own “point of contact” and conduct their own background checks via state, federal records or databases, as well as the option to use the FBI’s National Instant Criminal Background Check System (“NICS”) database. Montana is not a point of contact for the NICS and as a result, dealers must conduct their background checks by going to the FBI’s NICS directly. If a purchaser presents a state CCW permit, it exempts them from a background check when purchasing a gun from an FFL store.

Open and Concealed Carrying

Montana is a “shall-issue” state for CCW’s which are simply called Montana Concealed Weapons Permit holders. However, constitutional carry was recently signed into law by Montana’s governor and should begin to be in effect starting June 1st, 2021. Before constitutional carry.

Before constitutional carry went into effect via H.B.102, the preexisting policies are the following: open carry is legal in Montana without a permit for anyone above 18 years old. If any minors 14 years and up want to open carry they can only do so with the direct supervision of a parent or legal guardian.

Though not specifically stated in H.B.102, it can be reasonably assumed that Montana’s constitutional carry is similar to that of other states where permitless open and concealed carriers of firearms must be of legal age to do so just as the state’s policies mandated previously. For more details please see Montana’s reciprocity map here.

NFA Restrictions

Montana has moved to nullify federal laws it deems as unconstitutional when it comes to gun control regulations. Therefore, there are no “assault weapon” bans or magazine capacity restrictions to be concerned of. NFA items are legal in Montana which includes SBR’s, suppressors, and full auto or burst fire guns.

Magazine Capacity Restrictions

There are no magazine capacity restrictions in Montana. Enjoy those drums and belt-fed box magazines! We carry plenty of standard capacity magazines like the 30-round Advanced Warfighter L5 mag. Our favorite color is the translucent smoke one.

Mandatory Storage Requirements

There are no mandatory storage requirements for firearms in Montana, however, you should still exercise caution and can be tried for negligently leaving your guns accessible to children. If you need some good ideas or best practices for storing your guns and gear here are 5 firearm storage options.


Montana is a castle doctrine state and also has a stand your ground law in place which means you do not have the legal responsibility to retreat in the face of a threat or danger to yourself or others both in and out of the home place.

Ammunition Purchase

Other than armor piercing rounds that are federally categorized as “unreasonably dangerous ammunition” Montana residents can buy virtually any type of ammo. Federal rules apply so long gun ammo buyers must be at least 18 years old and handgun ammo buyers must be at least 21 years old. All online bulk ammo buyers must be at least 21 years old. The state of Montana does not require a license for the sale, purchase, possession or a record of transactions for ammunition.

Start Your Next 80 Lower Build with 80% Arms!

Montana residents are completely free to build their own firearms from 80 lowers and frames without any required serialization or FFL transactions. It's the perfect state to take advantage of your constitutional Second Amendment right and freedom to keep and bear arms. That includes 80% Arms! Grab a  jig and some buddies to enjoy that freedom together and let us know if you need any advice with your build at any point in the process. Friends, live free.