After reading the sticky regarding this (all 29 pages), I called the dealer to ensure they were pre ban.
There's only two ways to tell if a Glock mag is post-ban; if it has the "Law Enforcement/Government" restrictions stamped on the body of the magazine that were stamped on mags made during the 1994 AWB, or if it has the ambidextrous magazine release. There is no other way for anyone to prove that it's post-ban, because that is the stance of Glock's legal department.
Does any responsibility lie with the dealer/distributor or is it all on me?
Both of you are on the hook for this.
Massachusetts General Laws Chapter 140 Section 131M says:
Chapter 140: Section 131M. Assault weapon or large capacity feeding device not lawfully possessed on September 13, 1994; sale, transfer or possession; punishment
Section 131M. No person shall sell, offer for sale, transfer or possess an assault weapon or a large capacity feeding device that was not otherwise lawfully possessed on September 13, 1994. Whoever not being licensed under the provisions of section 122 violates the provisions of this section shall be punished, for a first offense, by a fine of not less than $1,000 nor more than $10,000 or by imprisonment for not less than one year nor more than ten years, or by both such fine and imprisonment, and for a second offense, by a fine of not less than $5,000 nor more than $15,000 or by imprisonment for not less than five years nor more than 15 years, or by both such fine and imprisonment.
The provisions of this section shall not apply to: (i) the possession by a law enforcement officer for purposes of law enforcement; or (ii) the possession by an individual who is retired from service with a law enforcement agency and is not otherwise prohibited from receiving such a weapon or feeding device from such agency upon retirement.
It's the exact same penalty to sell it or possess it; it's a 15 year felony.
High cap magazines require an LTC-A and must be preban to possess in MA (unless there are LE/military exceptions). In the case of magazines the law is about possession. The dealer may or may not be on the hook for selling post ban high cap mags, but you are on the hook for the possession of these.
See the info that I posted above, both are on the hook. Also, the LE exemption to the Mass. AWB is only for work guns (typically restricted to duty pistols/rifles/shotguns and approved off duty guns) and work guns that an officer retires with. LE can't just go around buying up post ban mags for all of their personal guns.
Also, there is no exemption under this MA law for military use, at all, not even when on duty. So if you know a soldier who has some post ban mags in their possession that were issued to them for use on duty, they're on the hook.
1) Glock says they don't know which magazines are pre-ban and which are post-ban. So Glock won't make a statement that will help you.
Not quite true, see the top of my post, and KMaurer's post.
Comparing the mags to the pictures, they aren't marked LE only, but they seem like they may look closer to the right side of the picture of than to the left.
If they aren't marked and don't have the ambi mag notch, they're pre-ban.
On the phone, the dealer didn't sound like he was willing to swap my 15's for 10 rd's so I am thinking I will dump these, eat the cost of some 10's, find a new dealer, and chalk it up as a lesson learned.
The dealer would have to be crazy to do this. Pre-ban mags sell for a lot more money in MA than 10 round mags.
If you have someone in a free state that could hold the mags for you, see if they will find someone wants to swap their old mags for your newer ones.
This is also a good idea. Mass. residents can own post ban mags or post-ban configured assault weapons as long as they're stored outside of Mass. (but interestingly, they can't buy post-ban configured assault weapons as a Mass. resident, even from an FFL in a free state, but if they owned them before they moved, then they can still store them out of state).
The answer is to do as much research as possible on how to identify a pre vs. post ban magazine for the gun you're interested in.
Yup. You need to learn all of the MA & federal laws regarding purchase, transport, possession, configuration, carry, hunting, etc. with any gun before you buy it. The penalties are severe, and ignorance is not a defense to violating these laws.
They didn't just give bad legal advice, they sold him illegal (Ok, possibly illegal) post ban mags and then refused to work with him after the sale. I'd avoid them for the crappy customer service alone.
I agree with you that the FFL made a dangerous mistake, and if I were in the OP's shoes I'd definitely go back and get the issue straightened out with the FFL. However, the gun laws in MA are so complex that some dealers are probably accidentally breaking some of them. But the number of gun stores in MA is steadily shrinking, so stirring up trouble will only hurt every other gun owner in the state.