Maybe to clarify the pinning a bit this picture would help.
When installing a new tip on a new ramrod I measure the depth of the hole in the tip and then subtract maybe 1/16 of an inch or a little less from that value.
Then I make a mark on my new ramrod at that dimension from the end.
Using a very sharp knife placed on the mark I then roll the ramrod so the knife cuts a little grooveall around the rod.
I repeat this rolling with a knife until it has cut about 1/32 of an inch into the wood.
Then taking the knife I cut from the short end of the rod at an angle to intersect the previous cut.
After I've got these angular cuts down to the depth of the circular cut I use a smooth toothed flat file to file the remaining wood down to match the hole in the tip.
While your doing this, try the tip several times.
A point will be reached where you can "screw" the tip onto the wood. By removing the tip you can see the polished areas that need a little more filing.
When the tip will fit all of the way to the shoulder you made with the knife apply some 2 part Epoxy to the outside of the rod end and to the hole in the new tip and slide it up so it is tight with the shoulder of wood.
Use a 1/16 diameter drill to drill the hole thru the metal tip and the wood.
When this hole is done, use your pocket knife tip stuck into the hole and rotate it several times.
This will form a little countersink.
Repeat this on the other sides hole.
Find a piece of brass, copper or steel wire that is 1/16 of an inch in diameter and press it thru the hole.
Cut the ends of the wire off so they are just a little "proud" of the outside of the metal end.
Then use a hammer to gently pound the protruding ends down into the countersink you made with your knife.
Now, use your fine toothed file to file the remaining part of the wire that is still sticking up so it's flush with the outside of the metal tip.
Stain the wood if you want it darker and apply a few coats of linseed oil, tung oil or even varnish to finish it off.