I use 1mm steps in size to clean out the chanter bore, and two reamers on the chanter bore. 
IIRC DMQ recommends (in the Pipersâ Review articles on making Taylor style drones) going from largest size to smallest when step drilling. David, is that still correct? I know some folks go from small to large, even with gun drills. Obviously , the type of tooling used will influence which method works best, I am speaking specifically of step-drilling with gun drills.
I go small large.
Large to small is more consistently accurate.
Now why would be David, 
Sorry, Now why would that be,David.
Can i try and answer that ? when you place the smaller drill into the larger hole the centre of the hole is maintained at the bottom of the hole
.If you put a large drill into a small hole the only thing centering the drill are the sides of the small hole which can cause the drill to wander !
RORY
But you do need an initial small diameter pilot bore, donât you?
Marc
As you step drill down the bore on a chanter blank, from the throat area down in 1mm drops,say from 6mm down to 11mm, each drill is only cutting a small amount each time in turn, so the drill will follow more easy up the bore after each cut in turn, if you drill say, 11mm in the bell end of the blank and step drill up to 6mm towards the throat area, how do you know if 11mm drill has cut straight into the 5mm pilot hole at the first step, I donât think it makes any difference either way its done, a good reamer will scrape the bore to the right dimension.
There are two issues here. One is concentricity of steps and the other is the path of the bore. It is fairly easy to maintain concentricity if the tool used to go from one size to the next is properly guided, i.e. a non-cutting part of it bears on and is steadied by a pre-existing bore. This principle applies whether you are creating the pilot for the next smaller size, as happens when drilling from large to small, or if you are enlarging (counterboring) the next larger size from a pre-existing smaller bore. The tools will have different configurations for these two approaches, but you ignore the guide principle at your own risk.
It is true, or at least likely, that a reamer will cut away the steps and leave you with the bore you want whether you have step-drilled small to large or large to small, but the reamer or reamers will work better and achieve a bore closer to the specified profile if the path of the step boring is straight. It is only in the interest of keeping the step boring as straight as possible that I make it a habit of drilling from large to small. If your experience indicates that drilling small to large gives you as good or better results, thatâs what you should do. Mine doesnât. To say one is right and the other is wrong makes about as much sense as arguing over what color a bag cover should be.
Certainly no arguing David, I like to get as much info from other makers
and the technique they use, it may also help anyone starting to make pipes or fancieâs to trying and make a chanter. all the best,Stew
A quick question before anyone starts in with their favorite bag color (I prefer bare leather⌠
)
David, are you using twist drills for your step drilling, or do you have a hoard of bushed (to guide from the larger bore) d-bits (or some other straight-flute drills)?
I step drill with long twist drills to rich the desired length up the bore at each 1mm step size, donât know about David.
I donât use twist bits for much. I use a range of pneumatic gun drills, and have worked up a set of tools that will go into a hole as left by a gun drill and start a pilot for the next smaller size. No bushings, as such. For those times when I need a bore size between the ones I can get with the gun drills, I use a set of very simple reamers, made from drill blanks, which leave the surface of the bore nearly as nice as what the gun drills leave. Complete details are in an article I wrote for the (Seattle) Pipersâ Review on the topic of Low-Tech Boring Bits. Wally will be happy to provide back issues at reasonable rates.
Forgive my ignorance here, 
âbutâ if gun drills are so good why ainât every pipemaker useing these super duper gun drills, :roll: or is it a case of I use Hi tech tools, So Heâa my pipes must be the best, is it the modern day case that we live in a world of glorified shight, like 90% of conversations on the hi tech âmobile phone is shightâ O how did the world ever survive without all this modern day technology, âWell it didâ it was called âLifeâ Craftsman produced beautiful & wonderful things of all kinds with the simplest of tools at hand, in the modern day world we have beautiful hi tech tools and produce hi tech shight, if a craftsman of old could work with these basic tools Why canât the so called craftsman of today work with them and make great stuff, what ever happened to skill, craftsmanship, and quality,Coyne & Harrington didânt need gun drills. the worlds gone mad!.
Forgive my ignorance here,
âbutâ if gun drills are so good why ainât every pipemaker useing these super duper gun drills, or is it a case of I use Hi tech tools, So Heâa my pipes must be the best, is it the modern day case that we live in a world of glorified shight, like 90% of conversations on the hi tech âmobile phone is shightâ O how did the world ever survive without all this modern day technology, âWell it didâ it was called âLifeâ Craftsman produced beautiful & wonderful things of all kinds with the simplest of tools at hand, in the modern day world we have beautiful hi tech tools and produce hi tech shight, if a craftsman of old could work with these basic tools Why canât the so called craftsman of today work with them and make great stuff, what ever happened to skill, craftsmanship, and quality,Coyne & Harrington didânt need gun drills. the worlds gone mad!.
Go take a âshightâ in an old fashioned smelly outhouse and wipe your bum hole with a corn cob as you ponder these questions and issues that you rant about. Perhaps the answers will only then come to you. Seek and ye shall find. 
Every pipemaker is not required to own one. Gun drills cost (in the US) around $100-150, save time, and produce an excellent result. Doing a pilot hole is a small part of the boring/reaming of pipes but getting a solid pilot hole can make the rest happen the way the maker wants it to. I do know that every pipemaker that I know who has tried one out has added it to his pipemaking operation.
I donât have contact with enough other pipemakers to know, but it would be interesting to learn if any maker who has tried gun drills has in fact rejected them and gone back to using earlier tooling.
The old masters didnât use gun drills, but Iâm guessing they used the best techniques and tools they knew of at the time. Thatâs where craftsmanship lies: not in stubbornly holding on to an old way of doing things in spite of demonstrably better results with something else.
Dunno, Reed, I donât think anyoneâs saying that gundrillâs are necessarily better,⌠theyâre certainly more expensive. Iâve bought 3 of âem on Ebay for $10 - $ 15 each, butâs itâs a pig-in-a-poke regarding size. I think people are just using them because they save time that can be spent on other pipemaking taskâs. Gundrillâs have been around a long timeâŚprobably as long as artillery. Using a bit that fitâs tightly, is self guiding, and boreâs on one side, like a D bitâŚis just a better way of producing a concentric deep hole than using a bit that chiselâs a hole from itâs center. The compressed air, for wood/coolant or cutting oil, for metal, that flowâs through the shank evacuating chipâs, keeping the cutting edge free from chip buildup, is whatâs responsible for their speed. I donât think anyoneâs saying theyâre âsuper duperâ or better than a D bit ground out of O-1âŚjust quicker.
Re:âthe good ol dayâsââŚI disagree. I think most craftsmen/artisanâs throughout history wouldâve jumped at the chance to use the technology at our disposal todayâŚat least to rough out their final productâŚto have more time to finesse, voice, fine tune. I agree that sometimeâs itâs difficult to tell the difference between folkâs on a mobile phone with tiny headset, laughing & rambling to themselveâs in a supermarket⌠from loony bin releaseâsâŚbut I gotta think that Coyne, Harrington, the Taylorâs wouldâve loved to have had a computerâŚand a CAD/CAMâŚand a HAAS CNC turning centerâŚand a mobile phone to call their honeyâs for some luvinâ and another beer. 
Glands wrote, Go take a âshightâ in an old fashioned smelly outhouse.
Were do you live pal, hear in England we live a bit more refine life, we have shit houses. :roll:
All the best, and hope your next shightâs a hedge Hog.