I have sat back for the last two years while people make worthless posts. When someone asks a question, answer it if you have specific knowledge of the topic. In your case, I take it you have no hands-on experience with the original gun in question? Your first post indicates that you have HEARD that the gun may have problems. For the love of God, people need to STFU unless they plan on answering the question posed by the OP. Myself, slad3d, bomber439, ATF-Hatman, Disco_Dante, and tte404 have actual experience with the gun being asked about, therefore, we gave our thoughts which are actually relevant. You HEARD from someone that there might be problems.
Try this - I heard you are a transvestite performing in a gay Las Vegas stage show at the Flamingo. I have no actual knowledge of this, but I heard it from someone. Does that make it relevant if someone were to ask "Does anyboday know Strelok?" No, this 2nd hand information has absolutely no relevance to the original question posed.
I apologize for the rant, but I am tired of having to read through garbage to see what real answers are being given. The OP probably has easy access to the Swiss Arms 552 and that is why they are asking about it. As a community we need to do a better job of leaving out the BS and giving straightforward answers so people can make informed decisions.