Hello

I got a used KJW M4A1 with a sawed off front sight. So, I bought a third party made M4 front sight and its too loose when I put it on the barrel. My approach right now is to use electrical tape to thinken the part of the barrel where the front sight fits.

Anyone got any better ideas on making it fit?

there should be a set screw under the sling mount tighten it down and it should solve your problems, if not, bulk up the barrel like your doing, or buy a different brand of front sight and hope it fits.

The front sight I got has screws around the ring where the sling loops. It uses phillips machine screws which I tightened as much as I could. I tighten the screws to the point they stop turning and the metal head started to file.

If you remove the hand guards you should see a round "ring" that is attached to your front sight. There should a be a screw there. Thats the screw that Durak is talking about.

I see it now. I didnt notice that when taking off the old sawed off front sight.

Changing the front sight caused much bigger problems...While hammering in the pins for the front sight. The impact of hammering in the pins caused the lower receiver to break off. The break is between the buffer tube and where the upper receiver houses the bolt. Fortunately, the damage was localized to only the lower receiver.

Next project is installing a new lower receiver.