M4 S-System and Receiver on CA M15a4

[Spudbum]

I have a CA M15a4 Rifle (the one with the long hand guard) and I have bought a D-boys M4 S-system Ris with upper receiver.

If I take the upper receiver off my CA and try to fit the d boys, the front pin doesn't line up and I cant slide it back.

Anyone have any suggestions.

If pictures would help let me know :D

Cheers

[dope_on_a_rope]

Re: M4 S-System and Receiver on CA M15a4

I'm not really surprised by this, the 2 are basically incompatible. I'm guessing the RIS system wont come off this Dboys receiver either?

[Spudbum]

Re: M4 S-System and Receiver on CA M15a4

Its sliding back and forth, and something is stoping it so I assume it does

[dope_on_a_rope]

Re: M4 S-System and Receiver on CA M15a4

Ahh, I see what you mean. It may well just be a case of compare the 2 receivers, and make them look the same by filing bits off the Dboys. Area's to look at include the hop unit, charging handle, the tang above the charging handle and the width of the front pin hole.

[Spudbum]

Re: M4 S-System and Receiver on CA M15a4

I have tried to fit it at the mo without the barrell and hop up. Its mearly a coupe of a mm, so yeah could be a case of filing something off.

Whats makes it worse is that because its metal, you cant see through it to see what its catching on :/