Justin,
Drilling the tang bolt and trigger plate without a press set up or jig can be real real tricky. It's much trickier than the other holes since you have to go through metal on both sides at an angle and metal is unforgiving plus the target is small.
If you do not have a drill press or jig, the following is a good option for you...
Do not use a through tang bolt! Use a large wood-screw (buttplate screw) for the tang and suitable sized woodscrews for the trigger plate. Many Southern guns did not use a through tang bolt.
I do have a center-to-center drill guide (or also called "the spike" in The Gunsmith of Grenville County):
http://www.redaviscompany.com/0883.htmlI think the line is worrying you just because of the angle you're viewing it at in that picture.
Also, I was able to clean up the countersink from my original attempt (no welder needed... yet
)
Looks pretty centered to me.
When I just lay the tang bolt in there, it looks good but when I put the tang bolt through when the barrel is in the stock, I can tell the countersink hole isn't quite perfect. When I drilled the countersink the first time, I didn't quite have the angle right. But it's just a tiny imperfection and I'm not too worried about it since I think the barrel browning will hide it anyway.
Here it is just laying in the tang outside of the barrel (looks perfect to me):
Then when I lay it in the stock, you can see just a whisker of the countersink sticking out. Maybe when I tap the trigger plate, it will draw that bolt head in a bit.
Worst case scenario, I can clean up the countersink a bit and if that fails, I'll get it welded and re-drill it. I want to wait until I tap the trigger plate but I want to pin the barrel first before I start working too much on the bottom side of the stock (i.e. trigger plate). To drill the tang bolt hole I just relied on the pre-inlet done by Chambers. That may come back to bite me but some of my instructions seem to conflict with what you should do first...