Elevator Lift

Printing a firearm, in most states, is the same as manufacturing the same firearm or firearm part by any other means. (Machining, casting, magical conjuring, etc.)

However, some states in the post Defense Distributed mass media hysteria, passed laws that made it illegal to manufacture firearms or firearm parts through 3d printing. These laws were limited to only the most awful states that are prone to following any form of anti-gun legislation, no matter how esoteric, so if you live elsewhere you should be fine. There is no federal legislation that specifically concerns 3d printing a firearm or firearm part (except for the requirement for a firearm receiver to contain a certain quantity of metal, but that is rarely enforced.)

I'm assuming California is one of those awful states..., yes?

None of the parts mentioned should be 3D printed. The exceptions of course are for FFF (form, fit, function) models.

Unless the "gun" is a movie prop, there is no reason (outside of FFF) to have 3D printed parts on it.

I am making the assumption that by "3D printer" you mean a "plastic" based machine. If you are using DMLS, then great... But there is no need for that expense when producing parts which can be machined faster/better.

Every state has it's own laws. Don't rely on GrabCAD, or a quick Internet search to give definitive answers which will keep you out of fines and/or prison.

Depending on where you live, there is nothing wrong with fabricating a receiver for yourself.

You dont think 3d printed parts would hold up to actual use?

Placing "weak links" on a firearm which introduce a chance of failure due to poor tolerances, or poor material properties creates a hazard for the owner and anyone nearby.

Consider Joe Average. He installs his newly printed parts on his rifle. "This looks awesome, and I saved a bunch by not getting those Yankee Hill machined parts." he thinks.

Joe fires away at his designated targets, until "something goes wrong".

Did the grip fail?

Did the foregrip snap?

Did his $600 Aimpoint fall on the ground when the Picatinny rail loosened?

Did the gun fall to the ground when the strap mount on a floating rail failed?

Did Joe average panic as the piece(s) failed? Does he have one or several unintentional discharges as the weapon falls to the ground? Did anyone get injured? Any property damage?

I fully support printing and testing firearm parts for the purpose of testing, but to sell them is too risky. The average person does not know the difference between a machined part, an injection molded part, and a 3D printed part.

Yes.

I don't know if I could pick between California, or Illinois if I had to decide which was worse.

For a multi-way tie for 2nd you'd have Massachusetts, Delaware, Connecticut, and Maryland... Almost forgot Washington DC, they'd be in the running for worst, but they are not a state.

Gun laws vary dramatically from state to state.

What is considered the "worst" by some, may be the "best" for others.

Printing accessories is not a problem as long as the accessory is legal in your state. Printing an upper receiver for an AR is also not a problem. Printing a lower receiver isn't a problem as long as you register it with ATF (The lower is what ATF considers to be the firearm.). Floating rails are absolutely NOT a problem. The serial #'d part is actually what is considered the firearm. Printing sights, floating rails, grips, etc., are definitely not a problem in most places.

That is what I was thinking... and I really do think if you used the stronger material... I believe it is called PETG (which my new machine can print), that something like a grip, foregrip, or rail would function properly.

Now, I wouldnt rely on a lower, upper, or barrel for actual use, but most of those parts already come in plastic and polymer.....

Polymer parts like those from Magpul and other manufacturers should not be considered the same as parts from a 3D printer. Even if the material used is the same, the printing process creates an inferior part when compared to an injection molded part.

I don't have a doubt that a printed, plastic part can function on a firearm. I doubt that anyone selling such a printed part is going to invest the time and money into the design, and manufacturing process to guarantee the part will function as expected without failure.

Without adequate testing every sale is a potential liability.

Let's assume you make $10 on every item sold. You'll only need 500,000 sales to cover a five million dollar lawsuit when someone claims they shot themselves in the foot because the 3d printed grip you sold them failed after being stored in a hot car trunk, or was dropped on the pavement a few times.

Well, the Op's question was about legality. It is his or her responsibility to determine their own skill level, engineering prowess, exposure to liability, etc. Not mine. He didn't ask whether I thought he should or should not. I have no idea what his financial situation is or what he might invest in manufacturing.

One dropping a rifle on the ground a few times should probably not have a rifle to begin with. I have no idea what Magpul's testing re dropping a gripped rifle on the ground is.

I hand built all three of the AR-15 rifles I own. All the furniture was manufactured my Magpul. That in mind, if the grip falls apart and that causes me to drop the rifle then I wasn't holding it in a safe manner to begin with. No matter how carefully and safely designed a product is, stupidity can always find a way to win. ;) That's what liability insurance can help to protect against. Any of you selling ANYTHING ought to be insured against liability and have a corp to protect your personal assets. "It could never happen to me."

Okay so let's assume that I wanted only to print parts for my personal friends and family as gifts for christmas, birthdays, etc....

Meaning lets remove the question of selling for a profit.... Has anyone on here built any parts for their firearms (and I do not mean integral parts such as the receiver, barrel, etc....) I completely and entirely am limiting the scope of such question to grips, rails, foregrips....

Can anyone comment on whether they have printed and used an accessory for their firearm and if it failed or has continued to function?

Yes. 3D printed parts can work.

The main problem is people design their 3D printed parts just like the injection molded parts they see.

3D printed, plastic parts are not a replacement for injection molded parts in terms of mechanical properties, quality or surface finish.

If 3D printed parts are going to be made and used (especially by people who may not know the difference between a quality part and a deathtrap), the part has to be designed with 3D printing limitations in mind.

I printed an AR15 lower receiver via stereolithography. It was OK for 30 shots, but it finally broke where the stock threads in. Thickening and strengthening that area would fix that issue, but then it would break where the hammer strikes it. Once that area is fixed, maybe the magazine well breaks next... It is a long chain of design, and testing to make a product work when dealing with any material, let alone an inferior one.

I've also designed and printed a few dozen custom sights for pistols. Initial ones were stereolithography plastic/resin. Later ones were were made of stainless steel via laser sintering. Those sights work fine because they are made of metal, and not subjected to many forces (apart from pressing them in, and recoil).

Grips, rails and foregrips are all subject to operator forces and need to be ROBUST.

Think of grips, and foregrips like the steering wheel in a car. You could make a really cool 3D printed steering wheel. But what happens when that steering wheel breaks? It isn't going to matter that it was too hot, or too cold, or turned too hard. The product failed because of the design and/or lack of testing. Anyone involved in the accident is going to be happy to blame whoever designed, sold, or gave them the steering wheel as a gift.