Side plate and lock bolt question.

[Rolf]

I've made the side plate for the practice pistol I'm working on out of 0.08" brass sheet stock. How do you "inlet" the heads of the lock bolts into the side plate?
It looks a bit to klunky with the boltheads resting on the surface of the plate.
I had planed to use a drill bit, but the point seems way too taperd for the job.


Best regards

Rolfkt

[David Veith]

 I would use a end mill. That and maybe take a little bit off the bolt heads so that they arn't as tall.
David Veith

[Bob F]

I used a counter sink to slightly inlet the screw heads into the sideplate.

[Dave B]

Rolfkt,
I ground the tip off one of my bits to make a flat face then ground a slight angle to each trailing edge making it into and end mill of sorts. After starting the hole with a regular bit just so there is a section of vertical wall in the hole to keep the flat bit from chattering off center I use the drill press to slowly take out the bevel left by the first bit. You could also use a piloted ream to do the same thing once you have your bolt hole drilled.

[G-Man]

The screw heads can make a big difference in the appearance of the sideplate area. 

If it were me, instead of countersinking the plate I would chuck those lock bolts in a drill and spin them against the edge of a file clamped in a vise to to reduce the diameter just a bit and show just a little more of the sideplate rimming them- then refile the taper the heads to the edge - the heads look a bit large as they are

On square shouldered screws somtimes used on Tennessee rifles, you often see that they would bevel the edge to reduce the thick look to the bolts.

Guy

[davec2]

I use a counterbore.  They are made in various sizes and I have a few for the common size lock and tang bolts.  They do a great job.  I have several with removable pilots and I make brass pilots to accommodate differing bolt shank sizes.  Clik on

http://www.mcmaster.com/#spot-facers/=3m4fhl

At the top of this page, click on counterbores and then scroll down to the middle of the page (there are four pages of info on counter sinks and counterbores.

[J. Talbert]

Dave,

It's been a  long time since I've looked, but are there any ready-made counter bores that you are aware of, which would cut a 3/8" head for a No. 8 screw shank.

Some time back when I last searched, I was unable to find such a critter.

Thanks,
Jeff

[John Archer]

I picked up a set of 'Pilot Point Tip' bits made by DeWalt. Can't remember how much they cost but they were fairly inexpensive.

John.

[davec2]

Jeff,

If you go to the McMaster link in my last post and look at the top of the page, you will see a line "counterbores".  There are two pages listed after counterbores.  Click on page 2434 and then scroll down to "Changeable pilot counterbores".  You can get a counterbore that will cut a 3/8 inch diameter and a pilot that will be a fairly close fit for a #8 Screw.  I use this type of counterbore and make my own pilots whatever size I need them.

[J. Talbert]

Thank you Dave!

Jeff

[J. Talbert]

Rolfkt,

Unlike Guy, I like the look of the bolt heads completely covering the plate as yours do.  I think it's a matter of preference, and also what you may be trying to copy.  In the absence of the appropriate counterbore, doming the head of the bolt right to the edge may help the appearance.

But I have a curiosity question for you.  The rear lock bolt appears to me to be rather high, and most curiously, it appears to be centered directly at the point where the breech  meets the stock.  Is this actually what I'm seeing?  If so, that would seem to put it a rather awkward location.

Jeff

[Dphariss]

Reshape the screw heads so they are thinner at the edge and it will look much better.

Dan

[Rolf]

Jeff,
  I'm using a GM 15/16" pistol barrel , a L&R Bailes pistol lock and a 5/16 white lightning touch hole liner. After I started fitting the parts together, I found that the Bailes lock is a little small for this barrel size and liner. The breech plug is 5/8" long. I've placed the lock, so that the touch hole liner barely clears the breech plug and the touchhole is in the middle of the barrel flat.




If I move the lock further back, the touch hole will hit the breech plug. If I move the lock down, the top of the pan will be too far below the touch hole. Ideally, I should of had a 13/16"barrel with a 4/8" breech plug. I was tempted to try and shorten the breech of the barrel, but I didn't dare for saftey reasons.


Best regards
Rolfkt

[Rolf]

Thank you all for your tips. I'll file down the bolt heads. I can borrow a 8mm (0.315") counterbore. Would that be suitable?

Best regards

Rolfkt

[J. Talbert]

Rolfkt,

I think your 5/8" breech plug is the key piece of the equation, but it looks like you've dealt with as needed.  The height of the rear lock bolt may just be the angle of the picture.  The hole in the lock bolster is certainly where it ought to be.

Jeff

[Acer Saccharum]

I like the counter bore because a little depth hides the edge of the screwhead, leaving just the dome above the plate. The other thing the counterbore will do, especially one with a long pilot, is it makes the seat for the screw square with the hole. Then the screw sits firmly, and does not tend to tip the plate in its inlet.

[Kentucky Jeff]

Acer,
   You sure like scratchin' nudy girls and goat boys on your gun parts...  I'm starting to worry about you!

[Acer Saccharum]

Sorry, I shoulda taped them over before posting the picture. 

back to the counterbore: If you have to angle a screw through the stock to avoid the rr channel, the counterbore will give the screwhead a good seat in the sideplate.

Tom

[keweenaw]

Rolfkt,

Don't worry too much about whether the touch hole liner hits the breechplug.  I was recently looking at some original Wilson barrels, ca. 1771.  The breech plugs on those are only about 3/8" long and the touch holes are almost on the face.  If you allow for a liner and are starting with a 1/2" long plug, you can't get the look of the original pistol.  Unless you really want a liner why don't you have me make you a touchhole counterbore?  It would allow you to get the touch hole closer to the breech plug. 

Tom

[Rolf]

Tom, thanks for your offer, but I've already drilled the holes in the lockbolsters and breechplugs, so I'll use the liners on these pistols.

Best regards

Rolfkt

[T*O*F]

If you have to angle a screw through the stock to avoid the rr channel, the counterbore will give the screwhead a good seat in the sideplate

Tom,
This is what causes most of those sideplate problems you mentioned before.  If the screw head is not 90 degrees to the plate, counterbore or not, one side of the screw head will hit the plate before the rest.  Tightening it further will concentrate all the torque of the head in one point, which will cause the plate to bow in that area.  When it bows, the plate will pop out of the mortise.

[Birddog6]

You can also cut those lil counterbores with a dremel & a small straight carbide cutting too too, if you are very careful. I have done several of them & also cut inlets in triggerplates to let the triggerguards come down further. Tedious but works . I use a dremel with a 3' flexible shaft so I just have the tool holder in my hand, rather than the dremel motor.