I have been thinking about building a mortar for a little while now. With 41P going through I was thinking about efiling a form 1 so that I have approval out of the way.

I have a few questions since this is my first non-SBR/Suppressor NFA item:
-A mortar is considered a "DD" correct?
-Is there any reason I can't e-file a form 1 DD?
-Is the process of filling out the form 1 for a DD that you intend to make the same as doing a SBR? I ask this because I seem to recall people building suppressors thinking they can't make a suppressor longer than they listed on their form. Is there any restrictions like this for building a mortar?
-If I get approval, but don't build the mortar for ~1 year is there anything wrong with that?
-Anything else I should be aware of before going down this path?

Its a lot harder to find DD NFA information than common things like SBRs and suppressors so I just want to make sure I do this right since I might only get once chance before 41P kicks in.

Yes if using fixed ammo.
No
No
Don't know.
Make sure you also follow state and local laws.

You should probably join Grog's forum.

What is the difference between the SBR form and the Mortar F1? Also, what is the relevant information I need to provide. Caliber 60mm/1m length? Would it be better to be bigger on these measurements or exact?

Joined...It looks like they are mostly a grenade launcher group, but I will check them out when my account is approved. Thanks!

Ben,

I have two buddies that are both here and on Grog's who have built multiple mortars on Form 1s, including an M224. Interestingly enough, all three of us (you making number 4) are named Ben.  I  did my last two DDs on eForm1, one of which was a mortar. I'd be happy to help you out however I can.  I'm about to board an aircraft and will be out of pocket for a few days shooting things and playing warfighter.  Send me a PM if you want so I remember to hit you up when I am back.

Cheers,

Ben

Thanks Ben! IM sent.

That whole length issue is a myth.  Just list the length you plan to make it.  If it ends up longer or shorter, you can notify the ATF.

The Silencer length thing concerns repairs, not building.

I'm one of the other Bens.  I'm the one with the M2 mortar and frag grenade.  Can't help you with the M224, but can help with an M2 build.  Or a frag build.

Thanks for the replies.

I'm not set on the 224 if the M2 would be easier to find information on I may go that route.

Wingnut, Do you know of any place to buy training rounds? That is my biggest concern at the moment.

Working on that issue myself.  The M2 is infinitely easier to build and maintain.

There is a source for training rounds, although they aren't full range, and while reusable, they are expensive if you lose them.  I've been working several sources for new, cheaper training projectiles. Try CDVS for training rounds. You can reload them with a 28ga blank.

M2 mortars are most definitely cheaper (by thousands of dollars), simpler, and easier to find accessories and parts for.  I am also working on updating the M2 mortar design to an M2A1 design- which will be cheaper, lighter, and have better range.