Ive searched on google and come up with many different conclusions regarding legality and the proper process. I have multiple shipped lowers that I want to sell and ship to individuals to be received at an FFL and follow the law. I live in a northeastern firearm-unfriendly state and want to avoid any and all possible chit chat with anti-gunners who may or may not be working the counter at the shipping station. Should I go USPS, FedEx, or UPS, and can someone tell me exactly how to go about this?

In my experience the counter people at all three will ask you if there is any hazardous content to the package you're shipping.
If the package content doesn't fall within one of their haz mat categories and you're not asking for insurance on the package, they generally couldn't care less what you're sending.

Well they always ask me specifically what is in the package. For example, I ordered a rail/handguard from Daniel Defense and called up to get an RMA to return it. At UPS they asked me what was in the package and I told them "machine parts," which wasnt an outright lie, but it wasnt entirely truthful either... and in this case a handguard isnt the same as a stripped lower.

Tell them "stripped lower".  They'll have no idea what you're talking about.

1) Make sure the FFL receiving is OK with you sending the items directly to them. Some, perhaps even many, won't receive from a non-FFL, and would demand you engage the services of an FFL in your own state. It's not a legal requirement, but it's courteous to check, first, and see what information they receiving FFL wants sent with the lowers.

2) The easiest way to avoid counter people once you know direct shipping is OK, would be to use an online shipper account to print out the shipping label, package it up and drop it at the local office or a drop box if it'll fit.

Noted and thank you for point 1.

Regarding point 2, this is kosher as far as the legality of things?

I just went through this and found given the hassle to cost ratio the best for the money is just have your local shop do it for you.

There is no law requiring you to present firearms shipments to common carriers in person. There are, for UPS for instance, shipper rules. UPS if I recall correctly requires you to present firearms shipments only at a UPS customer counter (not a UPS Store or other shipping franchise), or to ship with regular pickups from your business premises using your UPS business shipping account.

If you don't do so, UPS may return your package or deny your insurance claim if the item goes missing, but you've broken no laws.

this

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No, you aren't a licensed dealer and doing so is a felony.



Either one, just compare rates and know how far you'll travel to drop off at a UPS service center or FedEx Office location.




Read each carriers tariff:
UPS   Shipping firearms

FedEx Express & Ground


1. Tell buyers its their responsibility to find a receiving dealer who accepts shipments from nonlicensees.
2. Most FFL's will ask for a drivers license copy so they can comply with ATF recordkeeping requirements.
3. You don't need a copy of the receiving dealers FFL, but do need the first three and last five digits of his FFL#.
4. Go to ATF FFLezCheck and verify the validity of that dealer.
5. After you've read their rules and chosen the carrier, print and pay for your shipping label online. I recommend Adult Signature and insurance.
6. Drop off at the location as required by the carrier.

The only question that will be asked if you pre-print your label, is whether you want a receipt.

It is risky to ship high value items through USPS.  People do it, many get lucky.  The ones that still do it probably still think ebay and paypal are great ideas for gun things.