Some of you guys have made mentions that the feel of the PTR-91 U.S. made buttstocks are kinda chincy or cheap because they are hollow.  I remember someone suggesting, on a Russian shotgun forum, that they used expanding insulation to fill the hollow buttstocks on those guns.  When I got my PTR, it had something rattling in the buttstock, so I just removed the buffer and a very small piece of plastic casting fell out, it was a small piece of plastic that snapped off when they snapped the buttcap on, no big deal.  I just noticed that it was hollow and thought of the use of the expanding insulation that the guys on the Saiga forum were using.  Just be careful not to over-fill and it'd probably work best to squirt a little in there, wait a while then check it as this stuff has a tendency to expand for quite a while!  Anyone have any idea if this is worthwhile?  Just kinda wondering, I guess it's really no big deal, I really LOVE my PTR anyway.  Thought I'd throw this out for discussion.  Couldn't be much more satisfied with it anyway.  ARKAR

The original German buttstocks are hollow as well, so being hollow doesn't necessarily make them feel cheap.

I'd skip the foam.  Access to the inside of the stock is required to remove the buffer.

Just replace it with a real HK stock and be done with it.  Then you can also install things like a HK21 rubber buttpad.

Watch your US parts count, if that sort of thing worries you.

Surplus German G-3 stock set are dirt cheap.

I'm aware that the original HK stocks are hollow, I have an HK93.  The HK stocks do have the holes and the inserts for the stock pins and that seems to make them feel a little more "solid".  I just thought I'd mention this mod for folks that might want to, as you noted, keep track of their parts count.  

I have a surplus G3 stock that isn't hollow, it has the buffer tube hole.  About an inch past the push pin hole it is solid all the way to where it  attaches to the recoil assembly.  Can anyone explain that?

Dont fill it with foam, IMO, that would be ridiculus

Quoted: Dont fill it with foam, IMO, that would be ridiculus

To be honest, I was planning on changing mine out with an original HK stock, already have a source for it, I just need to order it.  I really prefer the look of the HK with the holes for the pins, not really that big of a deal, it just looks more natural on one of these rifles.  

Quoted: Quoted: Dont fill it with foam, IMO, that would be ridiculus To be honest, I was planning on changing mine out with an original HK stock, already have a source for it, I just need to order it.  I really prefer the look of the HK with the holes for the pins, not really that big of a deal, it just looks more natural on one of these rifles.

I think RobertRTG has stocks, his stuff is much better than advertised

I just ordered a black german stock set through cole dist. and couldn't be happier.  For $40 I got a brand new g3 stock/buffer assy. slim handguard, new pistol grip and new sling.  The stock was a brand new 1st gen. (w/ 3 holes) and is really nice.

umm if we replace the stock with a German one, is it 922 compliant?  i forgot what parts are US...I know that the handguard is US (as well as some internals)....anyone have a list on hand?