CarverGLX
Several years ago I faced this same dilemma which you are facing. I was using hard lead weights (recycled tire weights) I drilled the hole slightly larger than the round balls and beat them on an anvil with a hammer to flatten and tighten them up.It worked but was not symmetrical and was very ugly.
I posted basically the same question as yourself and got a response from one of the Hardbait Guru’s. I have searched the forums and tried to find this post so that I can give credit where credit is due. Unfortunately I was unable to find it. So thanks to the unknown Guru you get it from me in my own words.
This guru told me that I needed a tool , He had a name for it which I can’t remember but from his description of what it did I was able to make one. I used a small piece of aluminum sheet 3/8in thick and a 1/2in steel bolt. Using a drill bit, I made a concave dimple in the aluminum sheet then made another matching concave dimple in the threaded end of the bolt. I put the lead ball weight in the dimpled aluminum sheet then center the lip over the lead ball (that is the hard part, getting it centered half way on the lead ball) and the dimpled end of the bolt on top of the lead ball then proceeded to tap the head of the bolt with a hammer. Just a few light taps and the leadwill tighten in the hole, a few more and it will start to spread over the edge of the hole. It will not fall out.
You can file the domed top and bottom of the lead ball with a file and it looks pretty neat and professional.
Had not thought about Ben's use of soft solder. Also his advice about keeping your drilled hole about 3/16in. away from edge of bill is Spot-On.
Between work and grandchildren , I don’t have much time for tinkering with lures but I am still lurking in the shadows and keeping up with TU. I have learned much here through the unselfish generosity of the Guru’s of TU and when it is my turn, I try to give back when I can. I owe this board a lot.
Again, thanks to all who have helped me learn .
I hope this was not too confusing and helps you with your endeavor.
John