What tool do I need to buy to press thte rivet into place, the rivet to the sling under the front sight?
Good results come from using a ball bearing to spread the rivet.
I saw on here a while back that someone had a tool that he bought from a aircraft company to use on the rivet and it didn’t cost that much.
I’ve had good luck with either a large centr punch or a 16d nail with the end radiused on a benc grinder.
I had to do a little modification, but it works better than any other method I have used in the past…
R.Randel, tell me where did you find this tool?
That’s a trade secret. 
Very cool.
I have one Colt upper that had a roll pin installed in place of the rivet.
I have had good results using a 1/8" then 1/4" centering punch followed by a 3/8" drift to finish it off, while supporting the other side with a 1/2 drift. After a couple of hundred yours will look like a factory job.
I know this thread is old, but R. RANDALL, with your modifications, can you install if the sight post is already installed in the barrel?
This tool works well
Yes.
That’s WHY I did the modifications.
Ok thanks, just thought I’d ask since the one image showed one not installed on the barrel. Thanks.
randall’s tool looks like a modified ball joint tool - should work great
Here’s the tool: $38 plus shipping. Spruce is a great outfit.
https://www.aircraftspruce.com/catalog/topages/RapcoBrake.php
The rivet punch works very well. $10.
Where did you source that?
I’ve taken a bunch of those off over the years. Never put one on though!