I heat the end of the trigger red hot with propane torch then hammer it out, so it tapers down thinner.
elongate the piece somewhat so you have some matrl to work with. The forging/hammering out thinner will elongate it anyway.
File the forged out piece to a width you want for the finished trigger or neary so. At least trim it up to get rid of the raggety and uneven edges from the hammering process.
Clean up the front and back face of the tapered piece.
Now take the tip of the forged out piece and clamp it to a piece of round steel stock. The piece should be as small in dia as you want the curl in the end of your trigger to be.
Clamp the end to the piece of steel stock so it is at an angle to the steel stock. I use a small vise grip to clamp it together. Makes it easy to hold onto for the next step as well.
The trigger is clamped at an angle to the steel stock as you are going to wrap it around that piece of round stock in candy cane fashion.
You can go around more than one complete wrap and that will give you more than enough of a circle+ in the end of the trigger tip that you need for the curl.
To make the wrap around easy,,again heat the trigger section that you hammered out back to red heat with the propane. Then holding the vise grip with the trigger clamped to the steel rod in one hand,,take a suitible pliers and pull the trigger around the rod with your other hand.
It will spiril around that small dia rod very easily when red hot and form a twist curl the size of the rod.
Unclamp it from the rod and let it cool.
Clip the excess from the clamped end off and trim it carefully into what will become the end and inside of the curl of the trigger.
Now you have to push the twist/loop configuration back into line with the trigger itself.
Back to the propane and red heat once again. It's thin and heats up quick. Then simply push the curl back into place and straight with the trigger proper.
You can also do any small adj to the shape of the curl you want to like pulling the tip in closer to the inside or sweeping the start of the arc back a bit for looks.
Let it cool again.
Dump it in some very dilute muriadic acid soln to remove heat scale and you are done.
Takes longer to type than do.