I have a yugo sks that I removed the bayonet lug. I was reading over on surplus rifle.com forums that this might make the gun illegal. I have never heard of this and was interested  to know if this was a rumor. Looking back I wish I had never done such a thing now that I like collecting c@R guns, but you live and learn.
Thanks Charles

Altering a C&R can cause it to be no longer considered a C&R. By removing the bayo, you may have removed it from the list. Therefor you would have to put in the neccessary number of 922r parts and probably get rid of the grenade launcher.

I think the Tapco site has some info on this.

When I bought my C&R from a dealer, it had the Bayonet removed, although provided.  It seemed to be a requirement.  Lugs are still present.  I would be interested to see why removing the lugs at this point in history would make any difference, other than whether it must be sold through a standard FFL in interstate commerce.  I don't see how it would matter in a face to face deal, or for mere possession.  

As long as mods are not irreversible.taking parts off  is OK. Put on a pistol gripped stock is not.  Look at how they modify grenade launchers for CA sales......Changing out the mag for a duckbill is a no-no without 922 parts. If you sell it as a C&R it must be back in it original style. Some states require removal of the bayonet, this is just fine by the ATF. Remember, certain state laws superceed the fed law.