Post by mlin Here is my pending project to put "Classic Army RIS kit" on the MGC M4A1. I am using some photos to identify issues with the project.
1. Classic Army RIS - this is designed for airsoft M4A1. But I was told that is a 100% reproduced knight's type RIS. Ordered through an eBay seller in Hong Kong for about US$100 delivered. Quality is excellent (but not for real gun use). It's only 1/3 of cost of the real RIS. If any of you try to get a real knight's RIS, I urge you to rethink about that once you read my Classic Army RIS Story below.

2. Lower handguard/RIS rail - fits like glove to MGC M4A1. No modification needed, just clip on.


3. Upper RIS rail - here is the hard part.
A clamping mechanism that fits over the MGC gas tube is too tight. A little bit of filing or remove it completely will solve the problem. It's interesting that the front clamping mechanism is made of plastic, so sliding it through gas tube is not a problem, just press it harder. But the rear clamping is made of metal and I can not press it through the gas tube completely.

Another issue with Upper RIS rail is that I cannot clip it on like the lower rail. As you can see in the photo below, the back end of the upper rail stuck against the delta ring. Not by much, probably 1-2mm off. At first, I was wondering what's going on. It's the same dimension (length) as lower rail. Then I took a deep look, I think the problem is because of the height of the upper rail (2x taller than lower rail) and inserting angle make it impossible to clip it on right away. I am thinking about 2 possible solutions - filing/cut the rear corner of the upper rail (which will not affect the outer appearance after installation). Or detach the barrel assembly first to by-pass the trouble of delta ring and re-attach the barrel once the upper RIS rail is in place.

4. Here comes the question for any of you that had experience of detaching MGC M-16/M4 barrel. I tried to do so with the Hex keys supplied in the MGC package. None of them fit the size of the roll pin/fastener in the middle of the barrel. WHAT SHOULD I DO?
