All,
I hate leaving a thread unfinished. It leaves future researchers up-in-the-air on the questions being posed. Although a considerable pain, I have finally received a response from Sig Sauer that mostly answers my questions. And those answers are not what I had hoped for. Here are my questions and the responses from Sig.
Email: Me to Sig on 6/18/20-
1) Does Sig make a replacement gas piston assembly for the Sig MCX Rattler in 5.56? My gas piston assembly is totally different design than those replacement assemblies on your website?
2) I wish to replace the OEM flash hider. I do NOT want to use a suppressor. Just a different flash hider. The OEM flash hider appears to be pinned.
< Is the OEM flash hider pinned and also welded or braised onto the Rattler 5.56 barrel?
< Is the barrel threaded? If so, what thread & direction?
< If the barrel is not threaded, what is the barrel exterior diameter under the OEM flash hider?
3) It seems that from looking at the assembly, the gas system does not function from a hole in the lands & grooved portion of the barrel. Rather functions from a smaller diameter space located between the barrel crown and innermost portion of the flash hider? So, would removing the OEM flash hider and installing a different flash hider affect the gas operation?
4) I do not want to screw up the firearm & will not change the flash hider if there would be issues. I wish to know what those issues would be before I decide a course of action?
Response Email: Sig to Me on 6/24/20-
1) We have not built a (gas) kit for these yet, and we only have parts for warranty. Nothing for retail sale yet. You have a limited production item. Marketing is working on getting these out, but is delayed due to the virus.
2) It is pinned and welded. Yes, a standard ½ X 28 thread.
3) Most likely but not in a dramatic way.
4) We do not recommend removal of the flash hider currently installed by the factory. It’s a $600 mistake (Cost of a new 5.56 barrel system) to correct if things go wrong.
So, not all answers I liked, but better than no answers at all. During phone calls to Sig before the email response, they did say that the 5.56 Rattler is NOT designed for use with a suppressor. I am sure that is why the pinned & welded barrel.
My reasoning for these questions in the first place is because as anyone who has shot a Rattler knows, that barrel is very — very short! I had hoped that by replacing the OEM flash suppressor/hider with something like a Noveske KX5 to lessen both concussion & the chances of blowing your fingers off!
Having said all that, now that I have shot it some & placed a Magpul M-Lok Hand Stop Kit on the bottom rail, I feel more confident that I will retain all my fingers.
I may yet have the OEM flash hider removed and try a replacement. Would be gambling. Especially with the funky gas port setup……….
I have attached a drawing of how to me, the muzzle end of the 5.56 Rattler barrel appears to be designed. Drawing is not to scale. Just provided to give an understanding how the muzzle end of the Rattler system works. Strangest thing I have ever seen.......
Well, for some reason I cannot get the system to see my linked image. So here is the URL:
http://brucevarner.com/Drawing1.jpg
Thanks!