Legality of creating a push-pin semi HK receiver?

Am fairly interested in the POF series of HK styled pistols, modeled after the MP5 and MP5K. They come from the factory with a legal push-pin lower with the semi-auto shelf installed to prevent the installation of a F/A pack.

My question is, would it be legal for me to do the same thing to HK styled weapons I currently own? If I was to drill the hole in the receiver for a push-pin lower while still retaining the semi-auto shelf in place, basically the same setup as the POF weapons, would I be legal, or do I require a clearance letter from the ATF allowing me to do so without making a $10,000 hole/trip to jail in my receiver?

And the same question applies to creating a new MP5/K gun from a receiver flat, if I am creating the weapon from scratch, would it be legal to create it with the hole and self in it?

I think that was the MKE guns, not the POF.

Not having seen the design you plan, I am not sure if it is legal or not. But I would say if a F/A lower attaches and it works without mods, it is illegal.

Its POF, imported from Pakistan

POF-5-034-400x266.jpg

The new Zenith MKE guns are the same way. That said, they also have a carrier block in the rear of the receiver which prevents one from installing a f/a carrier. I doubt what you propose would be legal w/o this block, otherwise the POFs and MKEs wouldn’t have it either. BTY, I’m NOT an attorney.

Im so confused. Wouldnt you just be making a hole to connect the upper to the lower and not naking anything automatic or anything? I guess i dont see the issue if that is the case but i an fairly uneducated in this topic

HK weapons use a lower trigger pack, the F/A pack uses a push pin in the front to allow it to swing down… Semi trigger packs do not utilize the hole, they use a shelf welded in place on the mag well that the pack slides onto and it protrudes into the housing blocking the use use of a trigger pack with a F/A secondary sear… so the law states that if your weapon has the hole drilled, it is considered a machine gun… however some companies today can get around that by using the semi shelf that prevents the use of a F/A pack, while still having the push-pin hole to allow the lower to swing down…

So i would like to have a push-button lower, but still be legal having only semi-auto, so I would use the shelf and the hole… but I assume I’ll have to confer with the ATF…

That said, they also have a carrier block in the rear of the receiver which prevents one from installing a f/a carrier.

This is incorrect, as the POF guns come with a F/A carrier already installed, for those with registered sear packs wishing to go the NFA route with them…

No, you’re incorrect. Mine did not come with a full auto carrier and did come with a carrier block.

You are indeed correct, I mixed up reviews I had seen on Atlantic Firearms between the POF-5 and the AA-89.

The POF and recent zenith import MKE roller lock guns have a block welded into the right rear of the lower that prevent installation of a fullauto bolt carrier. They also have a tab welded at the rear of the pushpin support area that prevents installation of lower that has an unmodified fullauto trigger frame installed. I think you would have to send a sample to ATF tech branch for them to rule on the legality of these modifications on a roller lock gun in the standard HK semiauto format with a shelf instead of a pushpin. The big question is whether the juice is worth the squeeze.

Roger that, good write up. I appreciate everyones input.