If there is grit, or a burr that is interfering with the firing pin, that can cause the issue. Whether it's a burr, or some other outside contaminant is largely irrelevant though. Either way, let Mossberg handle the repair.
Please do the following to protect yourself and others from physical harm and legal liability.
1. Take the magazine out of the firearm and ensure there is no ammunition in the chamber.
2. Remove the firearm intact to an area where there is NO ammunition.
3. Use a KEYED [not combination] safety cable that goes thru the barrel and magazine well.
4. Throw away the key. I mean literally get rid of it. Send the key to a dumpster or sewer where NOBODY can ever find it.
5. Note the date and time you did this so you have a record of having NO access to a dangerous device.
6. Call Mossberg
7. Tell Mossberg of your experience.
[I would like to talk the legal department. Unintended discharges are the worst nightmare for arms mfgrs.]
If you do get hold of a legal rep that poo-poos this remind him of:
a: Remington 700 September 2018
b: Sig Sauer P320
c: Rossi Revolvers
If you still get no response ask the idiot for somebody higher up. You are trying to save them from big problems.
Your main goal is to get them to address the situation and tell you how to transfer that firearm safely to them for inspection and evaluation.
Arrange for reimbursement, but assure them SAFETY is your main concern.,
Your main goal is to keep yourself, your family, other innocents from handling your dangerous 715.
If this were just a maintenance and repair problem I would suggest contacting Mossberg's Joe Zakher at: firstname.lastname@example.org [ @old mossy - Is that still a good address?]
This advice may come across as scolding or preachy, but believe me when I say that the presence of this gun is a danger until it gets into the right hands. I'll be nice in my next post.
Also, Pete. Drop me a private message [called Conversation on this forum] and I'll discuss some other legal aspects that you should be aware of and how to find out how to dodge trouble.
-- I am not a lawyer. Following my advice without consulting an expert qualified and trained in the field may result in expensive fines or uncomfortable incarceration
The last time I was thinking of mailing a long gun in-state, the lady at the counter in the USPS said that was not allowed. I had heard and read otherwise and showed her a copy of the "official rules" stating it was OK non-FFL to non-FFL. Even to out-of-state should be doable as long as it is going to an FFL. Some people just want to say "NO" to you...
I agree that it sounds like the firing pin is not retracting back in all the way and/or broken. There is enough sticking out that it ignites the primer of the next chambered round regardless of if a finger is on the trigger. I'm glad no one was hurt because an unexpected event like that can take one by surprise!
Got my pistol back it looks like they replaced the 'bolt assembly'
I haven't got to fire it yet, because of fire danger no target shooting until September first
So I have to go to a local firing range
I have a new gun to test also that I assembled
I want to say
Thanks too ya'al on mossbergowners for the help
Went to Caswells n tested the gun
One misfire (soft strike) out of about eighty runs
It is the first time I have got to fire it without surprises.....
It was a lot more FUN
There is a big difference how hard the firing pin hit my snap caps
I was more interested in testing my AR I assembled,some minor problems
Some soft strikes about every tenth round
Gunsmith at work said bring it to him he will check head space, etc
Life is good