• It's time to cast your vote in the August 2025 Turning Challenge. (click here for details)
  • Congratulations to Ted Pelfrey for "Cherry Burl" being selected as Turning of the Week for September 1, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Gun Drill Source?

Tom Albrecht

Tom Albrecht

Joined
Feb 8, 2014
Messages
1,236
Likes
684
Location
Evanston, IL USA
The tool freak in me wants a gun drill now that I have seen Trent Bosch use one. Bosch and his daughter Kailee, did demos all day yesterday at the Robust factory in Wisconsin. Bosch only mentioned Ebay as a source, but there must be other sources.
Any ideas?
 
EBAy is the only source I found but them I didn't look real hard. What did Trent do with it. I was using them to drill through a goblet stem. Broke the first one. They are apparently very brittle.
 
john lucas said:
EBAy is the only source I found but them I didn't look real hard. What did Trent do with it. I was using them to drill through a goblet stem. Broke the first one. They are apparently very brittle.
Click to expand...

Bosch uses a gun drill to bore a 3/8" d straight hole to finished depth in his hollow forms, by hand.
He made up the holder with the air valve.
Bosch gun drill - 1.jpg
 
You can find some excellent ones on eBay in the $20 to $30 range the last time that I looked which has been a while. Buying a new one would be considerably more expensive.

John if you broke a drill you may have been running the lathe way too fast or not running compressed air through the drill or using too much force. Also back the drill out frequently because the chips can clog up the hole.

The first time that I used a gun drill was about a dozen years ago when I took a two-day class from Trent Bosch on creating his vessels of illusion hollowforms.
 
Clifton C said:
And here is my impromptu adapter...
Next one will be longer...
Click to expand...

Thanks Clifton.
Bill Boehme said:
You can find some excellent ones on eBay in the $20 to $30 range the last time that I looked which has been a while. Buying a new one would be considerably more expensive.

John if you broke a drill you may have been running the lathe way too fast or not running compressed air through the drill or using too much force. Also back the drill out frequently because the chips can clog up the hole.

The first time that I used a gun drill was about a dozen years ago when I took a two-day class from Trent Bosch on creating his vessels of illusion hollowforms.
Click to expand...

Thanks Bill, but like you said, it "has been awhile" since Ebay had drills in that price range of a decent size.
 
I saw a Trent demo and thought I needed a gun drill. A search on ebay found a USA made quality drill around 3/8” that had been resharpened with the wax still on the tip. I gave $20 or so delivered. Next step was to make a handle out of some scrap delrin plastic. It worked perfect.

So...I can drill almost as fast with a 1/2” spindle gouge and I don't have to hook it up to a air chuck. I never use the gun drill....but I might some day so its not for sale.
 
I have never use a gun drill, nor do I know what the benefit of using one is. Remember I'm isolated in the middle of Pacific here, like that tv show Lost... I know thats how gun barrels are made, so I'm guessing you could drill to depth very easily with one... Maybe somebody can point out to a video or a little explanation might shed some light on it. Thank you, Aloha
 
Not being a production bowl turner I just use my bowl gouge or detail gouge to drill out the center. On occasion I have used a 1" twist drill that I bought but I use it in the tailstock.
 
The gun drill has an airway to the tip. When connected to a compressed air it blows the chips out as it drills.
This allows drilling a hole as deep as the bit’s length in one continuous push. No need to pull the bit back to clear the shavings.
It also is pretty good at drilling a straight hole in endgrain.

If you use air tools a lot it is a quick way to drill holes for HFs
If you have to turn on the compressor and bring a hose to the lathe it is a slow way to drill holes.
 
hockenbery said:
The gun drill has an airway to the tip. When connected to a compressed air it blows the chips out as it drills.
This allows drilling a hole as deep as the bit’s length in one continuous push. No need to pull the bit back to clear the shavings.
It also is pretty good at drilling a straight hole in endgrain.

If you use air tools a lot it is a quick way to drill holes for HFs
If you have to turn on the compressor and bring a hose to the lathe it is a slow way to drill holes.
Click to expand...


And, the air, or "coolant", is the way these drills must be used, if not, as I was told by a manufacturer, the carbide tip will likely break off.

And, I did find a "manufacturer refurbished" drill for $35 with free shipping on Ebay. That's a lot less than the $90 from the manufacturer or MSC.
 
Tom Albrecht said:
And, the air, or "coolant", is the way these drills must be used, if not, as I was told by a manufacturer, the carbide tip will likely break off.
Click to expand...
I've had just the opposite result. Air or coolant will prevent breakage? I've used the same one with no air or coolant for about 10 years, with no breakage. Of course anyone could break it with abuse, but I don't leave it buried in the wood until it gets hot enough to discolor. I peck drill with it and keep the waste cleared off. Air does not clear out wet wood end grain curls. They stick in the flute after just reaching a little depth. Of course just my experience, evidently Trent has better luck.
 
Last edited:
Richard Coers said:
False. Air or coolant will prevent breakage? I've used the same one with no air or coolant for about 10 years, with no breakage. Of course anyone could break it with abuse, but I don't leave it buried in the wood until it gets hot enough to discolor. I peck drill with it and keep the waste cleared off. Air does not clear out wet wood end grain curls. They stick in the flute after just reaching a little depth. Of course just my experience, evidently Trent has better luck.
Click to expand...

When used as intended for drilling deep, straight, and precision diameter holes a coolant fluid is necessary. Not using coolant when drilling deep holes in metal will ensure breakage (which isn't quite the same thing as saying using a coolant will prevent breakage). The fluid serves two purposes, it maintains a constant temperature at the cutting tip so that the diameter remains constant and it flushes the swarf out of the hole so that the drill won't jam and break. Start and stop drilling won't work for precision diameter deep holes. Woodturners, on the other hand, don't need precise diameter holes nor perfectly straight holes so using air to help clear out the chips and quickly drill the hole are the only advantages. Otherwise, a spindle gouge or twist drill will work just about as well.
 
Richard Coers said:
I've had just the opposite result. Air or coolant will prevent breakage? I've used the same one with no air or coolant for about 10 years, with no breakage. Of course anyone could break it with abuse, but I don't leave it buried in the wood until it gets hot enough to discolor. I peck drill with it and keep the waste cleared off. Air does not clear out wet wood end grain curls. They stick in the flute after just reaching a little depth. Of course just my experience, evidently Trent has better luck.
Click to expand...


Like I said, that was a quote from the manufacturer--- maybe you should show them how to do it.
 
Tom Albrecht said:
The tool freak in me wants a gun drill now that I have seen Trent Bosch use one. Bosch and his daughter Kailee, did demos all day yesterday at the Robust factory in Wisconsin. Bosch only mentioned Ebay as a source, but there must be other sources.
Any ideas?
Click to expand...

Some gun drills are single flute and some are two. All the ones I've seen are straight fluted because the coolant carries the chips out and because of that there's no need to continually relieve the cut to clear chips and re-lube the drill.

Sterling makes gun drills. There are a lot of makers. For the life of me I don't see the advantage in woodworking. Unless it's for very deep holes. In that case, the relieved body of the gun drill might offer less heat build up from friction.
It'd make for a lot of airborn dust if one uses compressed air.

I just push the whole tail stock in and out. It's a habit I picked up as a machinist drilling deep holes in Molds. Peck a bit, Pull the tailstock out, lube the drill, clear the chips, then slide the tailstock back in and peck some more.
However when drilling wood it is really fast because the clips clear themselves when I pull the tailstock out and I don't lube with wood. I suppose I could use wax but never found it necessary.
 
Right, Sterling does make gun drills, and they make the best drills for wood drilling and guys who absolutely have to get a straight hole. If you were a woodwind instrument maker I think you'd then see the advantages that you haven't been able to see yet.
 
Tom, This was my quick and dirty, for proof of concept... It worked, If I were to make it again I would make it a bit longer, somewhere between 6 or 8 inches.
This one is 2 3/8th by 3 3/4's because it's the piece of wood (maple) I had at the time.
As I remember...
Turn between centers, tenon each end.
Grab tenon, drill to fit end of gun drill.
Reverse, drill and tap for air fitting (1/4 NPT)
Soak threads and end grain w/ thin CA, retap
Mark, drill and install threaded inserts.
Teflon tape, ball valve and air fitting.
20210125_211451.jpeg 20210125_211512.jpeg 20210125_211555.jpeg 20210125_211957.jpeg

Needed some light scraping to fit drill, Threaded inserts had to be filed/sanded flush. Thought of putting a gasket in the bottom but don't feel it's needed, a bit of air leaks by, but not enough to worry about.
Hope this gives you some ideas.
cc

Edit... my NPT was off, thanks Al, for the catch...
 
Last edited:
I know this is an old thread. But I have a question in regards to making my own. I plan on buying one of the gun drills off of eBay I suggested above.

Trent Bosch has a YouTube video describing the use of his gun drill. Near the end he says the video he talks about the gun drills being developed for drilling metal. But then he says that the carbide tip is sharpened for the ones he sells to drill wood.

For those of you who have bought the gun drills on eBay and made your own handles, do you find any issues with drilling wood since it doesn’t have his special angle? Or do you re-grind the carbide tip to a different angle?
 
To each their own, but I can’t figure out why anyone would spend money on a gun drill. I get the point about not having to clear shavings, but that only takes a few seconds. What am I missing that warrants spending $245 for one of Trent’s gun drill sets?
 
DSC00849.JPG
The 3 sizes 3/4", 1/2", and 3/8" with the built in threaded mount were purchased at Boeing surplus when I attended the symposium at Tacoma. The 7/16" 2 flute I won the bid for 4 in an online auction, then had to make an adaptor to use it with my handle.
The handle was made from a piece of 7/8th" hex bar stock bored out for compressed air and threaded on both ends for the drill bits and the airgun. If interested in a 7/16th" gun drill PM me, I have 2 extras
 
Jaramiah Severns said:
What am I missing that warrants spending $245 for one of Trent’s gun drill sets?
Click to expand...

Good question.

You can buy a bunch of parabolic drill bits for $245. Those are usually rated to do a depth 8 times bit diameter in metal before pecking (1/2" bit, 4" deep).

But what makes them preferable IMO is the ability to use in a tailstock drill chuck without an adapter or needing air. They can also be used in your drill press.
 
Jaramiah Severns said:
To each their own, but I can’t figure out why anyone would spend money on a gun drill. I get the point about not having to clear shavings, but that only takes a few seconds. What am I missing that warrants spending $245 for one of Trent’s gun drill sets?
Click to expand...
Jaramiah, I am not spending the $200 plus that Trent wants for his tool. I can get a gun drill of ebay for less than $20 with shipping. I can make a handle out of wood and air fittings that I already have so no extra cost there.

Yes shavings are easy to clean out by backing the drill in and out. numerous times. But I have used a friend's Bosch gun drill and it's even faster and easier. So that's why II want to make one of my own for cheap.
 
You must log in or register to reply here.
Back
Top