Drilling for ram rods

[xx54]

I plan to use a 48" rod and attach the end mill to it in a piece of angle as Craig said. This is how I have did all my ramrod drills in the past. The fact that carbide is apt to break was my concern about what length to purchase as the one that is attached to my post is 7" long, I believe it has  4" of flute on it for pulling out chips and could possibly shorten up the shank a little bit. Also, some of these end mills are not center cutting end mills. This one is and my cousin has experimented with some of these and he also has experimented with deep hole drills such as a gun drill.

[Not English]

XX, I'd go for it and see what happens. Let us know, it's an interesting idea. You should be able to feel  when the flutes are starting to load up. It's not necessary to use drill rod for extending the bit. In a past life I used to weld up 1/2" cobalt drills on to the ends of 6' X 1/2" steel rod to make drill bits for 12' diameter heat exchanger wheels. We rarely had drill bits snap off inspite of drilling through a combination 10ga galv. steel, corrugated aluminum, and 1/2" wall steel pipe.

[James Wilson Everett]

Guys,

A great help in locating the end of the ramrod hole is to keep the deep drill bit at the bottom of the hole, then use a house magnetic stud finder to find the exact location of the end of the drill bit at the breech end.  Really simple.

Jim

[Not English]

One last bit to add on my part. It is relatively simple to remove a  broken bit from a ramrod hole. There's several methods to locate the broken piece. I've never located a bit with a stud finder as Jim suggests, but it is a really dandy idea. One of the advantages of drilling the ramrod hole after the barrel is inlet is that it's pretty simple to remove the broken bit through the bottom of the barrel channel. Any holes and repairs will not be seen.

[Jim Kibler]

I wouldn't use an endmill.  The start of the hole is very critical and an endmill will tend to walk around since it has no point.   I would suggest a single flute gundrill geometry or a straight flute (two flute) drill.  Here are examples from McMaster  https://www.mcmaster.com/level-switches/material~carbide/drill-bits-for-hardened-steel/  These, of course, would need to be attached to another rod.

Other set-ups may work, but in my expereince are probably not as good. 

Jim

[jerrywh]

If I were to make a suggestion it would sound just like Jim Kibler's  Clear chips very often and keep it lubed with soap.

[Dphariss]

I stopped using ANY sort of twist drill for ANY deep hole in wood decades ago.
They simply don't run straight in wood or metal in a hole that is very deep.
Same as gun drills for a gun drill but gun drills have a bit brazed to the end of a tube with a full length V groove pressed in to match the groove in the bit. The bit has a hole and the tube supplies pressurized cutting oil to the working end. These were made from hardware store grade rod and will do several stocks before needing to be sharpened. Casehardening keeps they sharp even longer. Once started straight the never vary and can be aimed to give more mainspring clearance at the lock mortise when using small barrels. They don't break off either.
Link  is  to a die drill at MSC that could be welded to a shaft. Though I would drill the shaft then turn the shank of the bit to fit then put flux and brass in the hole before sliding them together. Then heat with the bit end down the promote bonding. Industry uses this design for things besides gun drills when runout is not an option.
https://www.mscdirect.com/product/details/71258248

[Dphariss]

These got misplaced when I moves and got a little rusty.
Dan

[flehto]

Attaching the drill to a length of same size round stock is important to eliminate "run out". I start w/ a length of drill rod, face one end, center drill using the lathe's  tailstock , then use a drill that's 1/64" undersize  and finish w/ a reamer.

An inch or so of the  drill shank is  turned  down in a lathe  and is a light press fit w/ the hole in the drill rod.  Both the outer edge of the drill rod and the shoulder of the drill have a 1/32" chamfer which accepts the high temp silver solder which holds the 2 together. The excess silver solder is filed flush and polished. Have checked the "runout" of these finished  RR drills and it was w/in a .001.

After building one LR and using a RR drill as described above w/ a flat bottom "point", the drilled hole came out exactly as planned. Some weeks later I visited Fred Miller and looked at his RR drills and they all had flat bottom "points"...same as mine. Fred had drilled 1000s of RR holes w/ these drills.

As was mentioned, some 4 fluted end mills have a center relief which doesn't cut, have limited chip room  and seeing the end mill's shank is hard, an inch or so has to be ground down accurately to fit into the hole in the drill rod. A butt attachment of the drill or endmill to the drill  rod  w/ weld or high temp silver requires a perfect alignment  which can be difficult to achieve. I've never used an endmill and prefer juts a twist drill w/ a flat bottom "point" which has plenty of room for chips. Never used a "store bought" RR drill, but if I had , the runout would have been checked.

My flat bottom drills  don't have a "point" and  have always started correctly as evidenced  by the final location of the RR holes. There are many different types of  RR drills and some  do the job and some  others don't.....Fred

[old dog]

As I prepare for my first build from a blank I have been reading everything I can find on "drilling the RR" hole.  I have not seen any reference to Track's rr hole bits.I have to assume they are not of adequate quality.  It appears there is a need for a sharp good quality bit.  It appears that most builders creat their own or have someone make one for them.  Many of us do not have the ability or equipment to create our own tools.Is there no one out there who makes a good quality drill bit for this purpose?
Old Dog

[xx54]

After some consideration and reading everything about ramrod drills, I think I will go with DPHARISS. His idea of using a die drill sounds like a good idea. My cousin who is a machinist has been experimenting with this. He thinks that is the way to go also. I too have a machinist background and I have a lathe to machine the ends for brazing and I will probably order one of these from MSC. My concern with the die drill is its ability to pull out the chips adequately. I do like the idea of it being carbide tipped. I know they use this style of drill bit for boring gun barrels. Surely it would make a good ramrod drill.
 

[RMann]

Same consideration and question as Old Dog.  R. Mann

[flinchrocket]

I have a 3/8 ramrod hole drill I got from TOTW over 30 yrs ago. I have used it several times without any problems.