For safety and to prevent damage to the piece I also would fit a stationary half-sleeve in the magazine opening immediately below the bolt (this would be a curved piece of spring steel or some such that would simulate the closed-bolt condition and thereby obstruct the feed path). In the unlikely event someone (a child, space alien, mother-in-law) were to insert a loaded magazine, the uppermost cartridge would be inaccessible to the bolt and thus prevented from feeding (this obstruction would be removable and only used with the dummy short barrel).
Assembled with the non-barrel and safety sleeve it would be impossible to feed, chamber or fire a round - in essence, a "non-gun". Meanwhile, no permanent modifications would have been made to prevent returning the piece to it's original long-barrel configuration.
The mechanical end of it is fairly simple, but would there be legal difficulties to making this kind of modification? Logic would say not, but laws and how they're interpreted are sometimes far from logical. I guess the key question is would the BATF interpret mounting a short solid or blocked barrel on an otherwise-functioning firearm "manufacturing" a "Short Barrel Rifle"? If there are any red flags, I'll call the BATF (I probably will anyway), but thought I'd get some opinions first.
Assuming this would CLEARLY not be a problem, would anyone have a shot-out, bulged, or otherwise unserviceable finned barrel available? This could be any length, long or short, since work will have to be done on it anyway to "dewat" it and fit it with a compensator.
Edited by Bob B, 13 August 2004 - 03:25 PM.