Any ideas for a locating jig for lock bolts?

[PKLeRay]

Hey fellas. I am wondering if anyone has come up with a jig that shows where your bolt holes will be on the side plate side, after locating where they HAVE  to be on the lock plate. Any ideas?

[gunmaker]

I use a drill press, with a tap size bit & drill thru the lock and wood that way (after pilot holes made in plate)---making sure all is square....Tom

[smylee grouch]

You might want to start by making sure the lock is inleted in the right place to start with so forward hole will pass between barrel and ramrod. Then do as Tom said or get one of the jigs that some of the members of this forum sell.

[Tom Currie]

Once you drill your holes from the lock side through to the sideplate side, rememeber to tap the lockplate by running the tap through the holes. Otherwise all bets are off on alignment.

[Long Ears]

There are a couple of memebers here that sell such a device. Dave Rase was selling them also. Do a search for drilling Jig. Bob

[flehto]

W/ the lock in place, the lock bolt holes  which have been drilled w/ the tap drill, are spotted and then the lock is removed. A body sized drill is then use to drill the through holes. The lock is then clamped in the inlet and the tap is inserted into the holes from the sideplate side and the lockplate is tapped. The stock has  been clamped square in a vise while drilling.

A piece of 1/8" thick brass is clamped on the sideplate side and the body drills which have a center punch ground on the shank end are used to center punch the brass piece. From the 2 prick punches, the sideplate is designed and made and then inletted.

Seeing this procedure is just a matter of transferring holes, there's no reason to know where the holes will be...anyways for me.....Fred

[PKLeRay]

I'm building a boucanier fusil for someone and the sideplate is large, which will fill up the majority of the side panel. The boltholes are predrilled in the plate. I was hoping someone had a jig etc that allow me to see where the holes would be on each side so I can align it properly. I have an idea of one but haven't nade it.

[Mark Elliott]

You don't need a jig if you make your own side plate and have a half way decent feel for straight and level.   If you don't,  then drilling the lock nail holes will be the least of your problems. 

Once the bolster is in,  I drill the rear lock nail hole to use it to remove the lock during the inletting.  I drill my pilot holes (tap drill size) from inside the lock mortice to make sure they are where I want them on the lock plate.   You need to make sure the front lock nail (if you make it by forging,  a lock bolt is made exactly like a nail)  will clear the ramrod.   This means you need to know where the top of you ramrod hole falls inside the lock mortice.   The front lock nail needs to be above this.  If the lock nail will fall too close to the edge of the lock plate,  You can file away some of the lock nail after it is fitted.

To drill the hole,  I camp the stock vertically in the bench vise with the lock mortice facing me.   You should have already located and center punched where you want the lock nails to exit the lock mortice.   Then it is just a matter to dill the holes with whatever bit you prefer (twist, brad point, small auger (for brace), or gimlet).    I believe it is best to do this with a hand drill, brace or gimlet.  Assuming the stock is perfectly verical,  you want to drill level and perpendicular to the line of the bore.    You shouldn't have shaped your lock panels yet, so it doesn't matter if you are a little off.   If you are building a kit and must use a pre-made side plate,  drill a little better than half way through from one side and then from the other side meeting in the middle.    All you need is a square to locate the exit holes.

Once the holes are through, turn the hole thing around and clamp the lock in the mortice.   Now take that tap drill bit and mark the hole location in the lock plate.   Drill the tap drill holes in the lock plate on the drill press.   

Before you put the lock back in the mortice for tapping,  drill out the lock nail holes with a clear drill.   Put the lock in the mortice and tap the hols through the lock nail holes through the stock.  Now, you can screw the side plate to the side of the stock using the rear lock nail leaving the side plate to spin around.  When I cut and file my side plates,  I leave the front end a little long and wide.    I orient the plate the way I like, hopefully it looks like the front of the side plate sufficiently overlaps the hole you already drilled.   If, not,  well this is where the art comes in.   As we were always told in art school, art is all about problem solving.   So, get busy being an artist.     

Assuming it looks like you have enough metal at the front of your side plate to do what you want,  clamp the side plate in place and remove the lock.   Now, use a clear drill and drill through the front lock nail hole from the lock side marking the inside of the side plate.   Just as with the lock plate,  remove the side plate and drill the front lock nail hole on the drill press using a clear drill.  This gives you a final opportunity to make sure that hole is where your want it in the side plate BEFORE you drill that hole.

Now,  I usually start out with drawings of all my mounts,  so I usually finish all but the front 1/3 of the sideplate.   If your want to leave yourself the most room for error,  just a pick a huge ass piece of scrap metal from which to make your sideplate and only drill the hole for the rear lock nail.   Then, you just drill the front nail hole and cutout the side plate around the two holes. 

At this point, you should have a partially inlet lock with drilled and tapped lock nail holes AND a sideplate blank with two holes for the lock nails.   Just finish the sideplate and screw it to the stock and scribe to inlet it. 

Easy peassy, and NO special tools or jigs.  It took more time to write this than it takes to actually do what I described.   

[Bill-52]

PKL,

I use a drill press for the lock bolts in order to pinpoint exactly where they are located on the lock, stock and the side plate. After establishing where the side plate is to be located, I'll use an awl to dimple where the bolts are to be located on both the lock plate and side plate (or side panel wood if the side plate holes are already there).  When drilling, I'll place the dimple on one side on a threaded rod with a coned point, secured in the drill press plate and aligned with the drill bit.  Each hole is drilled partially through before drilling from the other side.

I use adjustable outriggers on the butt and forearm to stabilize the rifle.  I know exactly where the hole will be when the rifle is positioned such that the coned rod is in the exit point and the drill bit is aligned with the entry point.

I can't claim this as my idea -  I read about it somewhere (Shumway's, Alexander's or Dixon's book?).

Bill

[RAT]

After you thin the side plate side of the lock panel to it's proper width parrallel to the barrel... Mark where you want your holes to be on the inside of the lock mortice. Place the stock on the drill press table with the side plate side sitting flush on the table. Drill your holes through the lock mortice using your tap drill. Now, remove from the drill press, clamp your lock plate in the mortice, and drill through the side plate side, through the stock, and through your lock plate. The holes will act as a drill jig. Remove the lock plate, enlarge the holes in the stock with your clearance drill, clamp the lock plate back into place and run your tap from the side place side through the lock plate. Everything should be aligned and the bottom of the heads of your lock bolts should sit flush with the side plate side. Make your side plate out of sheet and the holes in the stock will determine where the holes in the side plate will be. Shape the side plate as you want around where the lock bolt heads end up.

[RAT]

Duhhh... Sorry I missed the part where you are trying to use an existing side plate.

Dixie Gun Works makes a jig. It's similar to the one described in the book Recreating the American Longrifle. I used it once on something (I think for barrel pins) and my holes still came out wrong. I can't remember if it was wide enough for the lock area.

David Rase also makes one. He's a member of the forum so you can look up his email by searching the member list.

[D. Taylor Sapergia]

Perhaps you are wondering if the already existing holes in the side plate can be aligned with where they need to go in the lock plate?  to check that, simply strip the lock, and lay the side plate over the inside of the lock plate.  then you will see if you can position the holes:  rear one in the rearmost part of the plate's bolster, and the forward one in the centre of the forward part of the plate.  Even having done that, you still need to know if that forward screw is going to pass perfectly through the web of wood between the barrel and the rod hole.  So check that too.
One thing that 'offends' me in an otherwise lovely build, is the forward lock nail exiting close to the top horizontal edge of the plate, when it is best in the middle of that part of the plate.

[Dr. Tim-Boone]

Remember no one can see both side panels at the same time. You can position the lock as it needs to be and then you can angle the bolts  "a little bit" to have them come out where you want them if the side plate is already drilled...  "a little bit"... but sometimes that is all you need

[Mark Elliott]

Perhaps you are wondering if the already existing holes in the side plate can be aligned with where they need to go in the lock plate?  to check that, simply strip the lock, and lay the side plate over the inside of the lock plate.  then you will see if you can position the holes:  rear one in the rearmost part of the plate's bolster, and the forward one in the centre of the forward part of the plate.  Even having done that, you still need to know if that forward screw is going to pass perfectly through the web of wood between the barrel and the rod hole.  So check that too.
One thing that 'offends' me in an otherwise lovely build, is the forward lock nail exiting close to the top horizontal edge of the plate, when it is best in the middle of that part of the plate.

Taylor,  

I agree that a front lock nail at the edge of the lock plate is much less than desirable.   However,  with the late southern rifles I build (small barrels (Rice Southern Classic ) and large lock plates  (Chambers Late Ketland), if I do a good job of drilling the ramrod hole nice and close to the barrel channel in order to have a nice thin little gun,  then I end up with the front lock nail in that ugly upper position.    It is a matter of which would you prefer,  a real tall, bulky looking stock and a lock nail in the middle of the lock plate, or a slim, graceful stock with the lock nail in an ugly position.   Usually, I am going to shoot for a compromise, but the front lock nail is almost invariably going to be above the center line if I get the stock looking like I prefer.  

Of course,   this is only an issue with a very specific type of rifle.   For most guns, you shouldn't have this problem.  Now,  if my clients would pay me to build a really nice late English lock with a small plate (like on an L&R Durrs Egg or Manton),  we could avoid that problem.  I would be THRILLED to do that, but it will add several hundred dollars to the build assuming I take an L&R lock and make new internals.  

Best,

Mark

[flehto]

On the Bucks County LRs that I build, the lock is inletted higher {the top of the pan is higher than the bore centerline} so that the front lock bolt is more tewards the center of the lock nose and  misses the RR hole.  W/ a 3/32 or slightly thinner web  at the breech, just how centered the front lock bolt hole  is w/ the lock nose, is secondary to the above requirements.  Using a #6-32 front lock bolt helps some in that the groove in the bbl isn't as deep. As was said....a thin web is necessary for a slim LR and sometimes to achieve this, other than ideal situations have to be tolerated.....Fred 

[D. Taylor Sapergia]

I understand how this phenomenon occurs, and have been forced to do the same.  On another occasion, when it was apparent that the forward lock nail would be offencibly high on the lock plate, I added a disc bolster to the inside of the plate, and made a blind hole.  And in truth, the frizzen spring does a good job of disguising that 'too high' screw.  I agree that the architecture of the stock through the lock vertically is way more important.

[satwel]

Here is the method I used last week on the Chambers English fowler that I am building. Because of the circular recesses in the sideplate, the lockbolt holes can only go in one place. I carefully marked the centers of the holes on the sideplate and drilled each one with a 1/16" bit. Then I took a scrap piece of sheet copper a little bigger than the sideplate, and using the sideplate holes as a guide, I transfered the location of the holes to the piece of copper sheet and drilled those with a 1/16" bit. That gave me a template for the exact location of the sideplate holes in relation to each other. I laid the copper template on the outside of the lockplate and carefully positioned it so the rear lock bolt hole would properly fit the bolster and the front lock bolt hole would just clear the underside of the barrel. I marked the centers on the lockplate using the holes in the template, installed the lockplate in the stock, clamped the stock in my drill press and drilled through the lockplate and through the stock using the tapping size drill bit. Took out the lockplate and drilled again with the pass through sized bit. Put the lockplate back in the stock, put the tap in the drill chuck and turned the chuck by hand to start the threads. Took the lockplate out of the stock and finished tapping each hole, reassembled everything, installed the lockbolts and found they were perfectly aligned with the holes in both the lockplate and the sideplate. No binding at all or wiggling them to get the bolts started in the lockplate. The front lockbolt just misses the underside of the barrel, yet doesn't interfere with the ramrod.