countersinking tang bolt head into tang

I'm doing my first-ever build. Half the time I'm making newbie mistakes, the other half I catch myself before I do something stupid. So far - knock on curly maple - I haven't done anything that would cause me to have to scrap the stock.

I have a question on the tang bolt. With much trepidation, I successfully drilled the hole through the tang and trigger plate (that center-to-center drilling jig in a drill press actually works!) and threaded the trigger plate.

I countersinked the tang some, but not enough. My question is how do you guys get the screw head to be flush all the way around the tang? I aligned the tang bolt hole such that it wouldn't go through the trigger guard at an angle, and I was successful at achieving that. However, that leaves me not exactly tangent with the arc of the tang. The photo below may make more sense:

The bolt should be squared to the arc of the tang. It only requires a little of an angle when it enters the trigger plate. From the photo, it looks like you could re-drill it, then plug the hole in the plate, if necessary.

Bolt hole should be drilled square with the wrist and tang.Doesn't matter if its straight through the trigger plate.

You have to re-drill the hole using the same tang hole at a sharper angle to the trigger plate. In other words square the screw head on the tang bolt with the tang. You are going to end up with 2 holes in the trigger plate or have the existing hole welded close, file and start over, or get a new trigger plate. No biggy just part of the learning curve.

It would seem that in order to redrill the trigger plate hole it could end up needing to go through the plate at an inopportune angle. IOW, the trigger plate only has so much area on it that can accept the tang bolt and if none of that area will "straighten" the traverse of the bolt, then the tang bolt hole in the tang and wrist will have to be re-drilled.

I'm no expert. Just looking at the geometry of the whole thing. Correct me if I'm wrong cause I'm all student and no teacher when it comes to building the longrifle.

Correct me if I'm wrong but looking at the angle of the screw head relative to the wrist the hole was drilled to intersect the trigger plate behind the trigger.
If this is true, there should be no problem in drilling it so the screw is perpendicular to the tang in its present location. In other words, the hole thru the tang should work.

By making the screw perpendicular to the tang it will want to hit the trigger plate in front of the triggers which is fine.
Even if it wants to break thru the trigger plate under the trigger guard that isn't a major concern because after the countersink is made in the tang to get the screw head flush with the top of the tang, when the screw is installed you will see exactly how much of its length needs to be cut off to prevent it from actually projecting from the bottom of the trigger plate. It should be flush to just slightly below the bottom of the trigger plate once it is shortened.

As for the existing hole in the trigger plate, don't weld it shut. Just install a short piece of threaded stock like the end of the tang screw that you cut off. If you use Loc-Tite to install it and file if flush with the underside surface of the trigger plate no one will ever notice it.

It doesn't look like you have it countersunk very far as of yet. It also doesn't look like you are off that much to me. It might not be as obvious once you get it countersunk further. You could deepen the countersink in the tang and then reshape the head of the tang bolt so that it looks like it is square to the tang. That might be worth a try before you try to drill a new hole. Tang bolts are a lot less expensive than a new trigger plate or a new tang.

He could never countersink it to look or work right as is. It must be re-drilled. After a time the wood is going to compress, then the bolt will have to be tightened, then it will look like manure.

To add to what everyone else has said plug the existing hole in the wrist so the drill doesn't wander when drilling your new hole. This is not a major catastrophe just adds a little more time to the project and I'll bet you never do it again. As an aside I like to drill my initial hole with the tap drill but yours is already screw size so that is out.

runnball said:

"...plug the existing hole in the wrist so the drill doesn't wander when drilling your new hole..."

Click to expand...

Agree...I've used a snug fitting hardwood dowel epoxied in as a repair when installing wrist strengthening hardware on some rifles which involved replacing the front tang wood screw with a 1/4" bolt that went through a new style trigger plate and threaded into the trigger guard.
I had messed up the trigger guard trying to D&T it for the bolt.

But since I'd already drilled out the front wood screw hole for the larger 1/4" bolt, to restore the rifle to its working condition, I used an oak dowel in 1/4" hole from top to bottom, so the original tang wood screw could be used again.

The Tang Bolt as stated by everyone here should be re-drilled or at least on the next gun, enter the tang squarley. This can be done by looking at it very carefully and discriminately. You can use a center combination square. They are used for finding the centers on round stock. It's a sliding right angle with the blade permenately set at 45 degrees, but the edge of the blade is set to pass through the inside corner of the square. Place it on the sloping wrist so the blade hangs down like the drill bit would. Mark it on the side of the stock, flip the square around, if the edge of the blade that was the center was towards the muzzle , flip the square around so its reversed and points to the butt. Mark that. The marks should be very close, get the average. That's the angle you want to drill through the wrist. Now when I first started building guns I use to use a Flat head/ oval head tang screw, but when I filed the head flush it left a razor sharp edge. Now I counterbore my Tang Bolts. You can buy counterbore bits in either 82 Degrees or flat /flush bottom. The 82 degree bits are more forgiving. Or you can just use a 5/16" or about drill bit, and make your screw fit the counter bore. The screw should have a shoulder. The counterbore only goes in the tang alittle bit, maybe 1/16". Be careful, DON"T OVER DRILL THE DEPTH. Drill the tang hole with the tap drill first, then through the triggerplate, then a body drill before using the counterbore drill. I'm not a machinist, they could describe this better than me. ...Geo.

I have had a tang bolt issue the same as you have shown. I counter sunk the tang more deeply, deepened the screw slot, and filed the tang bolt even with the top of the tang. The result looks good, but I am unable to post any pictures.

I use a screw that is threaded into the hole and cut it approx .020"-.030" proud. I then peen it over on both sides to lock it in place The upset metal fills in all of the thread voids and then when filled down, one can not see where the threaded hole was.

I'll second what FrankPa said. I've done the same thing a couple time and you'd never know. :wink:

i made the same mistake on my first build, but the angle wasn't as off, so i got away with countersinking the hole and reshaping the bolt very slightly. regretably, i think i dodged a bullet where you can't and it looks as though the hole will need to be refilled and redrilled.

don't feel bad: this will not look as obvious as you fear, and in the end it will work better.

good luck with your project. now, next time (and, yes, there will be a next time...)

I think anyone that has built a few rifles has run across this issue. You did early so you will get past it this rifle.

I would weld up both the tang & the triggerplate with a wire welder (do not quench them) and then redrill them both. Use a pilot hole angled correctly on Both holes. If the triggerplate hole is going to be a fairly sharp angle, you may need to counterbore the inside of the plate a tad so the drill doesn't walk on ya.
Tap them thru the stock with Everything in place.

:thumbsup:

Here's a couple more photos. The tang bolt exits in front of the trigger. The way this trigger plate is made (Chambers fowler), the area for the tang bolt is very thick, but not very large in diameter. Can I really drill through there at an angle? Doesn't seem like it would work out.

I see you have a chambers kit. I guess you see your problem is the tang was drilled in the wrong spot . You could order a new breech plug. But you'll have to fit the plug to the barrel, which now with the dovetail(s)in, is a pain to do. I've filled the hole in the tang, but it's tricky because the stuff wants to come out as you do it, plus it gets slightly hardened when welding. You could use a oversize screw. Tap the existing hole slightly countersink the hole, and solder with that Tix solder & flux from Track of the Wolf. It has a real low melt temp, but is really strong. Low heat is important, because you don't want to burn the flux. If you do it won't stick.After you tap the hole, tin the countersink part of screw,
when the solder melts, screw the screw in tight. make sure the bottom of the screw slot will be ABOVE the surface of the barrel. Then after it cools, file it flush with the surrounding metal, re-drill your hole where you want it. The soldered screw should not turn out on you and should stay put when doing this, just don't overheat it, it has a melting point of just under 300 deg. ...Geo.

If you are planning on browning the barrel, soldering a screw in there will stand out like a sore thumb. (IMHO)

I vote for welding it up with a wire welder. (NOT a stick welder) File it flush, anneal it & redrill the holes. I have done several tangs & once browned you couldn't tell it was ever misdrilled.

And Yes, the triggerplate is thick enough for the screw to be at a slight angle. (IMHO)

Here's a couple more photos. The tang bolt exits in front of the trigger. The way this trigger plate is made (Chambers fowler), the area for the tang bolt is very thick, but not very large in diameter.

Click to expand...

Your pictures explain what you did and what you were thinking. All very logical till you saw the angle of the bolt head in the tang.

You do need to relocate the bolt hole in the tang. The limited space on the trigger plate demand it.

If your like me, you don't have welders etc. that you could use to plug the hole in the tang. You could put a matchin wood screw into the existing tang bolt hole so that it lines up. Might look a bit funny though . You could also replace the breech plug and tang if you think you can readily match it to your tang inlet. I think you will need to plug the hole in the wrist as explained above before you redrill the tang bolt hole.