[Derekfiveo]

For educational purposes.

Reading confusing things on Full Auto capable USC conversions. Hkparts sells 3 stage trigger lowers and other burst lowers. I do know that if you were to go full auto you have to cut a notch in the USC reciever. But do the hk parts lowers then make it a full auto? Or do you have to buy the FBI lower and swap parts. All pending a 9mm conversion as the bolt is full auto.


Minus all legal issues such as 922r and ATF forms.

Breakdown

9mm conversion plus all other ump parts with hkparts lowers or is it required to get FBI lower for full auto after modification of the reciever

 

[Lohe]

If you cut the notch in the upper YOU HAVE MANUFACTURED A FA FIREARM and if you are caught you will go to jail for 20 years.

There is NO legal way to convert a USC to FA.
Can you come up with some BS reason to do it if you are a manufacturer?
Sure.. but it probably won't hold up in court.

If you are doing a conversion (to a UMP look-alike NOT function-alike)
you really need to swap the SA parts out of the USC lower and put
them into the UMP lower.

If your bolt is either a factory UMP 9mm FA bolt or one of MM's FA bolts you're going to have to
modify it to fit the USC receiver. If it is one of SEF's bolts it will fit the USC receiver without
modification but I don't think they are tungsten filled (the SEF bolts). In SA you really don't
need the extra weight from the tungsten as it's just going to provide more mass to wack
into the front and back of the receiver (wack being the scientifically correct term .

 

[SEAINC]

I believe I read some where that AviatorDave can machine some parts in the UMP FA lower and made them SA only. Of cause, when Tom did my conversion he swap the USC lower internal into FBI lower and he also fill some epoxy to block a pocket in the lower to block FA parts from being install. I believe US made 9mm USC bolt from Adam is FA bolt and he also has US made 9mm UMP bolt but can't fit into USC receiver.

 

[AGENT_95]

I hate to change the topic, but what king of epoxy was used to fill in the empty pocket in the lower receiver? will that ever be removable (for a later sale) or eat away at the plastic?

 

[USMC-F4]

I hate to change the topic, but what king of epoxy was used to fill in the empty pocket in the lower receiver? will that ever be removable (for a later sale) or eat away at the plastic?

Either use a Delrin plastic block milled to fit the opening and blind pin the block in. Or you can use Devcon steel filled epoxy (2 part mix, my favorite) or any other 2 part epoxy to pour into the lower receiver area.
For the price of lowers I would not worry about reconstituting the lower to its original state. Epoxy will not eat the polymer lower.
My 0.02...

 

[straightgrain]

@derek,
Just to be very clear... There is NO method or process or conversion available by which the USC can be converted to a civilian legal full auto weapon. An 07/SOT manufacturer could do it legally and create a full auto weapon that would be classified as a "post sample" only available for LE/Mil and bona fide demo to same by FFL/SOT's, but that would be silly. The real thing already exists for them in the form of a UMP. And for less work and expense than conversion!

 

[DarkPhoenix]

I hate to change the topic, but what king of epoxy was used to fill in the empty pocket in the lower receiver? will that ever be removable (for a later sale) or eat away at the plastic?

I guess I went a little ******* and used JB Weld in mine. It is nice and smooth and is holding up nicely