Hi all, I'm sorry if this is the wrong place for this, it didn't fit into handguns or rifles (for obvious reasons). I picked up a GSG-5 with the 3 weaver rail tac grip at the gunshow today (the rifle version with the fake can), and have been doing some research. In my research, I have found many people who are in potential huge legal trouble based on some of the customizations I've seen. There are issues with both the rifle, and the 'pistol' versions that I'll post below. Rifle version:-- DO Not install the 'non' stock version of the stock, it puts it below the 26" minimum length for a rifle. Also, you may wish to keep an eye out if you have a collapsible or folding stock. The measurement is done according to ATF with the stock extended fully, however this is not 'law', it is the ATF's idea of the law. Long story short: Just do not install the rear-end of the GSG-5 PK, otherwise you don't get the overall length correctly. Pistol Version: There are a ton more issues with the pistol version that will get you in trouble real quick. 1- DO NOT install a Vertical Fore-grip. By installing one of these, you make the pistol a 'rifle', which because of the short barrel, makes it an AOW and requires a $200 tax stamp. 2- The same applies with installing a stock to the PK. If you install a stock, it is considered a rifle, and thus, an SBR. 3- If you EVER install either of these items, your GSG is no longer a pistol. ATF has a 'once a rifle, always a rifle' policy, thus if you install either of these, you are basically screwed legally. Best bet is to remove them, get rid of them (to avoid constructive possession) and pretend you never owned them Interesting point to this: because it has a stock, I think the GSG-5 A (PK barrel with a stock) is not legal according to the NFA as far as I can tell. In my research, I think I am correct on all these points, but they are definitely up for discussion. I really don't want to see anyone here get in trouble because of foolish NFA stuff.