Cutting slots in barrel keys

[lanedh]

Over the years I've lost more than my legal limit of barrel keys when in the field, so decided to make all barrel keys 'captive' with a finishing nail into the barrel channel. I've had the worst luck trying to drill a straight line of holes through the key, then finish up with a too-small file to break thru and end up with a slot. The drill bit usually grabs the web of the adjacent hole and snaps off, or the bit wanders off-line and you get a wobble. Then after drilling through you have to somehow break through the remaining stock to result in clean parallel sides, and using a swiss needle file is torture.

Recently a coworker suggested using a Dremel abrasive cutoff wheel to grind the channel out. I did two Lyman GPR keys yesterday in the space of half an hour, and they turned out well. The resulting channel is a little wider than I'd like and the wheel diameter is too large to use on short keys such as for pistols and small barrel rifles, but for the GPR and that size it works great. You can find Dremel cut-off wheels in packages of five at hobby shops, Home Cheapo, and on-line hobby supply sites. Note that Dremel also offers a composite cut-off wheel (looks like laminate or fiberglass laminated with resin, it's black in color); it's a littel bit thicker so the results will be a wider slot. The wheel I used looks like some kind of vitreous material, chocolate brown color.

I first punched a straight line of dimples on the key stock as a guide. Then I held the key in a pair of narrow-nosed ViseGrips and applied the wheel to the work. My Dremel is an old one, one speed, turns up 18,000 rpm, so just a light pressure does the trick””let the wheel do the work. When the wheel is about to break through the key, flip the key over and grind away what's left from the opposite side.

NB: PLEASE WEAR EYE PROTECTION; THE CUTTING DISK COULD FRACTURE AND THROW PIECES IN ALL DIRECTIONS.

The grinding wheel does very smooth work and leaves very little clean up. Try it, you'll like it!

Good luck.

Bluejacket

 

[Vaino]

I drill a series of slightly undersized holes and then use a jewelers saw to remove the webs. A thin needle file enlarges the slot and a radiused needle file does the ends. Seeing there's no real accuracy involved asre the slots, the only criterion is that they look somewhat "neat" and the drill remnants are filed flush......Fred

 

[grey8833]

Bluejacket:
The keys I started with had slots, but they were way too short to clear the barrel staples. Simply scribed a line on the keys centerline, got out the flat needle file - had a "dead" side and a "live" side, clamped the key up on the big bench vise, put the file through the existing slot, pointed the live side down, put the handle on the file to save my hand and started filing. Be careful, it goes a lot quicker than you think. Maybe 15 minutes to finish the key up. Flat file kinda self guides, but the center scribe line helps. Both came out really nice.

Mike

 

[lanedh]

That's the sensible approach if a slot already exists, and I've done that before. My problem with the Lyman GPR keys is that they are made of pretty thick solid stock, so I was very happy that the Dremel grinding disk did the trick.

BJ