Sure, you have a couple Hi Point carbines lying around. You got as nice new TS model, an old Planet of the Apes model, and even an old beater that has seen better days. Well, why not make that beater into a SBR?
Basically, you turn this,
According to the BATFE, a SBR is a "shoulder-fired, rifle bore" firearm with a barrel of 16 inches or shorter or a firearm that overall length is less than 26 inches. This means that any Hi Point rifle, if it is chopped shorter than 26-inches overall, and/or has a barrel of less than 16-inches, is regulated as a SBR by the Feds. Sure you can pull this off with a hacksaw at home in about five minutes, but it would be as illegal as making counterfeit $100 bills on your laser printer. To do it proper, you have to apply to build one.
To do this, download and fill out an ATF Form 1 (pdf). Before sending it in (with a $200 check or money order) you have to attach a passport photo, a set of fingerprints, and have your local law enforcement chief sign off on it saying they are cool with you.
Then you wait.
Typically, this takes 6-8 months with some horror stories of 10-12 months not being uncommon. While you are waiting for it to come back, you can figure out your build and even stock materials for it, but you can't make any changes to the gun that would violate that SBR rule until you get that approval letter and tax stamp back (yes, it's an actual stamp). Until then, enjoy your carbine and take it to the range often.
Once you have your stamp, go ahead with your build. Since the Hi-Point series of carbines are all blowback action with heavy bolts that retard the recoil to cycle the weapon, as long as you don't dink with the receiver and bolt of the gun, you should be good to go with chopping the barrel as short as you want. Then you can replace the stock with whatever works for you.
This HI Point SBR has a folding Vz.58 style stock; the front sights are remounted on the abbreviated barrel, which is threaded to accommodate a suppressor. As long as you are competent in your home workshop skills and have a lathe or barrel threading kit, this is a DIY project. These kits include a threading die, and a special bore guide to make sure your threads are strait. If not, you may want to contact your local gun shop about NFA work.
Overall, this build (minus the suppressor) can be had for under a $1000 including the tax stamp and carbine itself. The prospect of suppressing a Hi-Point SBR, especially in subsonic .45ACP for those Model 4595 guns, can be very appealing as the number and availability of 9mm, .40 and .45ACP suppressors grow with each passing day.
This Hi-Point SBR has an ATI Beretta-style stock that has been modified as well as another Vz58 folding stock.
Again, another Vz.58 Style folding sock, but with a picatinny rail across the top, extended aftermarket magazine, detachable broomstick foregrip and threaded for a suppressor
One thing to keep in mind though, once you make a SBR you have to keep up with the regulations regarding them as they change from place to place. In addition, you cannot just loan it out to a friend in another state, as the ATF looks dimly on that. Finally, you may have special problems sending back an SBR to Mom to fix, as unless they are a Class III dealer, they may not be able to have it on site.
But in the end, you can wind up with a Hi Point Carbine that could fit into a backpack or large glove compartment, and then turn heads every time you are at the range.
So there you have it. Happy modding, and if you make one, be sure to post it to the forum so we can all take a look at it!