You can only cut off about 5" of the barrel w/o cuttting into the forearm.  How much of the forearm can be cut off along w/ the barrel?  What is the shortest possible barrel length?  I woulnd' thave any poblem cutting off the front sigts and shortening the forear a bit.    I would really like a 7-9" barrel for use w/ a 3 lug mount suppressor.    

I see sierra pappa has an ar stock converion so it coudl be turned into a folder.  There are not action parts in the buttsock are there?

Thx

http://www.thefirearmblog.com/blog/2011/03/08/new-beretta-mx4-storm-submachine-gun/

If you want to leave enough barrel beyond the hand guard for threading 12" is the shortest you can go. I'd seriously recommend against cutting into the hand guard, it's unlikely there's any good way to do it without it looking like a total bubba'ed disaster.

ive seen some that have their handguard chopped about. flush with the front of the top rail.  AR folding sights were installed.  The back wings were removed too.  Pics on the internet, ill look for them.  

I know the gun has a rather long telescopic bolt so obviously the myssle would have to be ahead of that.  Also, there has to be an attachment point ahead of the front of the bolt where the barrel attaches to the handguard part of the receiver, at least i do not see how that could not be so.  Therefore, the muzzle could be no shorter than that point.

the barrel has two swells in it, onne in the front at the end of the handguard and another a little farther back.  Obviously the bar%el could not t possibly be shorter than the rear swell but maybe the front swell is required too to hold it all together...

By the time you did all of this work, you could probably have an MP5K clone that was reliable and SBRd

Hell just get a CZ scorpion with a 'brace' and you don't have to screw with the stamp.

The CX4 is neat and functional in stock form, and nicer still with the barrel chopped, but by the time you get into receiver/rail modifications etc, you might as well pick a different base gun