I just bought one with a fixed stock. Could I legally put a collapsable stock on it?
Just curious and a little confused since these guns aren't affected by the AWB.

dont see why not,,,

The HK91 collapsable stock makes an already hard-kicking rifle feel like it kicks even harder.  They're kind of pricey, too.  Very cool looking, though.

Alot of people say its unpleasant to shoot but IMHO I think its very mild.  The curved buttplate is what takes getting used to....it feels like it wants to slide off of your shoulder.  This has never happened to me yet so it must just be a mental thing.  Getting a good spot weld on the stock isn't too difficult either.  I guess its personal preference.

I just added a HK collapsable stock last month and didn't notice any difference in the recoil, but would agree that it is a little different in getting used to the feel on the shoulder. I just sits a little different with the pad it has mounted to it. I would watch some of the auction sites for a bargain though (mine was $160 delivered on gunbroker.com), as they can cost a bit. I have not compared to see if there is any difference in the HK collapsable or the one offered by pof-usa.com ($175), but enjoy mine a lot. Not to mention it adds a "evil part" and a nice look.

In my opinion I think the best stock for the HK 91 is the Ace Folding "Galil" style tube stock.   It is much more comfortable to shoot just  like the original fixed stock and folds very compact to either side.  All you need is to switch out the buffer and back plate on your original fixed stock and it will match your finish.  Email me and I can send you pics of mine.  

[email protected]    remove the no spam.

Second the ACE stocks.  You can also put their boom-tube model on there for a really cool look, and it does a good job of handling recoil if you put the recoil pad on it.  

www.pof-usa.com/hk91pl.htm   and FAC