Previous Drilling of Chamber

[Cloudrepair]

There are tools better for the job of enlarging a existing hole and whether it is bad practise or not every machine shop I have worked for from the time I started as a full time machinist over 20 years ago (All job shops) has used 2 flute drills for this kind of job.
They teach it in school and they also try to teach how to sharpen drills if that tells you anything.

That is probably why you don't see a lot of these three and four flute drills in sales flyers.
I have seen exactly two of these multi flute drills in all these shops and have used them for that kind of job and they wear the same way just not as fast because they are designed for it.
I am a machinist and on a lathe there are many ways to do it. my experiance is why I do it this way, drill then a boring bar to make hole true to the spindle axis then ream.


the reamers job is to make hole the size and shape of the reamer accurately.

Setup is key also

Edited

 

[Cloudrepair]

You have it partially right. Center drill, drill, bore, ream is a common practice. Drilling out an existing hole is not. That's the boring bars job, and for good reason.

While you are enlarging holes with a 2 flute drill and dulling it, causing it to need resharpening you are work hardening the metal. 1144 is notorious for that as is 416. Those hard spots affect that bore all the way down the line. Drills chip, reamers dull and chatter while ruining the bore, and push away from it and taps get stuck and break. There are many reasons why a quality machinist does not use drills for anything they were not designed to do.

You really need to ask yourself why you need to sharpen drills so often. IF they are used properly they will damned near last forever. A dull drill or chipped drill is operator error and operator sharpened drills need to be scrapped for anything under 5/8 or 3/4. Two flute drills are perishable tooling, same as a carbide insert. if it's dull or shipped it's scrap.

Of course hobbyists are a different story but in my world with labor rates anywhere from 1.50-2.00...oops....That's per minute.... and up, 2.00 is pretty common(per minute), your boss can not afford to have his machinists wasting time sharpening drills that are on a fast track to making scrap parts.

We drill holes in 4150PH anywhere up to 2ft deep. You would be shocked how long and how any feet they will drill without needing resharpening . We'ne since gone to gun drills and it's a toss up as to which drill is better. The gun drill can run without retracting it for peck drilling but that's about the only benefit to us buy using them. Cost per foot is a toss up.

I'll admit that it would be better to use a boring bar.
If I was doing hundreds of barrels I would use the proper tooling.
I haven't had to sharpen any of the drills I have used for this.

 

[butchlambert]

You have it partially right. Center drill, drill, bore, ream is a common practice. Drilling out an existing hole is not. That's the boring bars job, and for good reason.

While you are enlarging holes with a 2 flute drill and dulling it, causing it to need resharpening you are work hardening the metal. 1144 is notorious for that as is 416. Those hard spots affect that bore all the way down the line. Drills chip, reamers dull and chatter while ruining the bore, and push away from it and taps get stuck and break. There are many reasons why a quality machinist does not use drills for anything they were not designed to do.

You really need to ask yourself why you need to sharpen drills so often. IF they are used properly they will damned near last forever. A dull drill or chipped drill is operator error and operator sharpened drills need to be scrapped for anything under 5/8 or 3/4. Two flute drills are perishable tooling, same as a carbide insert. if it's dull or shipped it's scrap.

Of course hobbyists are a different story but in my world with labor rates anywhere from 1.50-2.00...oops....That's per minute.... and up, 2.00 is pretty common(per minute), your boss can not afford to have his machinists wasting time sharpening drills that are on a fast track to making scrap parts.

We drill holes in 4150PH anywhere up to 2ft deep. You would be shocked how long and how any feet they will drill without needing resharpening . We'ne since gone to gun drills and it's a toss up as to which drill is better. The gun drill can run without retracting it for peck drilling but that's about the only benefit to us buy using them. Cost per foot is a toss up.

tra, you ain't the only person to turn on a mill or lathe. I don't chamber barrels out of 1150 or 4150ph. I don't dull my drills predrilling a CM or SS barrel. I've done a couple LW barrels with their terrible LW50 grade SS. I'm kinda like Jackie Schmidt. It machines like 17-4PH.
Remember, we are just the "RAMS" raggedy ass masses that machine with a hacksaw and chisel.

 

[shortgrass]

Give it up guys, you will never convince someone who knows it all/ has done it all, that they don't/haven't. Seems to be the way of the interdnet gun boards these days.

 

[ridgeway]

Give it up guys, you will never convince someone who knows it all/ has done it all, that they don't/haven't. Seems to be the way of the interdnet gun boards these days.

Typical button pusher, lol

 

[butchlambert]

Neither are you. Nor can you, and your pals, et al. avoid the realities of metalworking. Trying to convince rookies that you and they can perform miracles with worn out machinery is nonsense. Metal working is like reading the wind, you can't do it once and be a pro. It takes years, and even then you can not squeeze miracles from your equipment. If you could the need to upgrade your tools would not exist.

I for the life of me cannot see the logic in preaching that ignoring sound machining practices will produce quality results. Let alone insinuating that the tooling manufacturers are idiots.

Not to worry, you guys are still my idols, I can only dream of becoming as talented as y'all. Sure would have saved me spending all my money buying quality modern equipment in my quest to supply my customers with the best quality products possible.

BTW Butch, 1150 is a condition, not an alloy or grade of steel.

tra, I still don't machine it! I have a 2.5" round of 17-4 ph1150 round by 7' in my material rack. Now if the tooling mfgs say predrilling a chamber dulls tooling and work hardens materials, I guess I had to use a cheater bar on my tailstock and didn't know it. I've been using the gorilla method to use the same HSS drill to predrill about 30-40 ppc barrels as I didn't know that it was dull.
Come on guy! You're a joke! You might know that there are several members on this board that have forgot more than you ever knew about machine work.
I'm not going to put you on ignore because playing with kids like you is a lot of fun.

 

[ridgeway]

Don't forget Butch...Any time your tool gets dull, it's your fault and it's junk and needs to be thrown away. Like I said...button pusher.

 

[Cloudrepair]

You have it partially right. Center drill, drill, bore, ream is a common practice. Drilling out an existing hole is not. That's the boring bars job, and for good reason.

While you are enlarging holes with a 2 flute drill and dulling it, causing it to need resharpening you are work hardening the metal. 1144 is notorious for that as is 416. Those hard spots affect that bore all the way down the line. Drills chip, reamers dull and chatter while ruining the bore, and push away from it and taps get stuck and break. There are many reasons why a quality machinist does not use drills for anything they were not designed to do.

You really need to ask yourself why you need to sharpen drills so often. IF they are used properly they will damned near last forever. A dull drill or chipped drill is operator error and operator sharpened drills need to be scrapped for anything under 5/8 or 3/4. Two flute drills are perishable tooling, same as a carbide insert. if it's dull or chipped it's scrap.

Of course hobbyists are a different story but in my world with labor rates anywhere from 1.50-2.00...oops....That's per minute.... and up, 2.00 is pretty common(per minute), your boss can not afford to have his machinists wasting time sharpening drills that are on a fast track to making scrap parts.

We drill holes in 4150PH anywhere up to 2ft deep. You would be shocked how long and how any feet they will drill without needing resharpening . We've since gone to gun drills and it's a toss up as to which drill is better. The gun drill can run without retracting it for peck drilling but that's about the only benefit to us by using them. Cost per foot is a toss up.

First of all I haven't said I need to sharpen drills all the time only that a machinist should know how.
A quality machinist learns all or most of this your rambling about in the first two years or he dose not do well because it is a competitive field.
A quality machinist knows feeds and speeds to do these jobs and learns to get it done without trashing the tooling with what is available at the time because sometimes that's what has to be done.

I do everything from aerospace to tractors and it is all done with 10 percent schooling and 90 percent experiance. Maybe closer to 2 to 98

Edited again

 

[shortgrass]

Typical button pusher, lol

Ya',, I guess you could call a 13yr. old, with a new I Phone , that's watched too many U-Tube videos a 'button pusher'.

 

[ridgeway]

Well good for you! LOL. All I have to say is I feel bad for your employees to put up with an attitude like yours...

 

[Cloudrepair]

Sure I push buttons, I can at least say that I own those machines with the buttons, the facility they are used in, and the company. Actually I sign the checks of my button pushers. Machines without buttons are obsolete.

ridgeway, you need to grow up, your sophomoric attitude is disgusting.

You are getting desperate when you have to attack someone personally. As usual you have made this about you and your superior knowledge and skills.

I can see your point of view from a owner standpoint but do you program and operate along side your employee?
I program and operate along side the owners.
These are good guys That run a great shop and very busy.
They know the job because they work right next to us.
And we push it pretty hard with top grade tooling.

 

[Cloudrepair]

My employees tell me and even our customers that they love their jobs. I must be doing something right. Clean facility, climate control, not making my machinists cobble up tooling for every job, goes a long way. Those that like working in archaic shops with antique equipment, and filthy conditions don't have to worry. In my area those shops have all been run across the auction block.


Our employees program themselves. What good would they be if we had to do everything for them? The juvie here sounds like he could be one of those types. Of course the operators don't do the design work, or generate the drawing files, but they can fully function from then on and finish the job. Management is out on the same floor and when problems arise they and the machinists deal with it.

I hope the day comes that the probe has to move out of his mothers basement and he gambles his , and his family's and his employes future, he will need to change his attitude fast and learn how to survive in today's metalworking environment.

I figured the op was asking from a home shop standpoint hence the answer.
I still use a small manual lathe at home at work 17 years ago I used a drafting version of mastercam
To draw up parts and wright programs with g and m codes for parts that needed fourth and fifth axis work also.
Mastercam has come a long way from there and most of the work I get now comes with a parisolid also. But I still need to draw them up sometimes and much more then I like we have to call the engineer because of his mistakes or even help them redesign there parts.
We don't even have a drill press in the shop that work is all done with small open cnc mill machines that are much like the manual knee mills

 

[230grRN]

It's threads like this that have gotten so far off topic that I rarely if ever post anymore, so this will be my only comment on this, so if you reply looking for a response it's not coming.

Poor practices take place in shops everywhere, every day for all sorts of reasons. The fact of the matter is if your in a production environment it matters where margins are razor thin and dead lines matter.

On the flip side if you're a guy in his garage on a Saturday morning just putting a chamber in barrel, you're going to grab the best fit twist drill and get the job done, you're not going to think "man I should get the correct tool for this because I'd hate to kill my $10 HSS drill".

 

[shortgrass]

It's threads like this that have gotten so far off topic that I rarely if ever post anymore, so this will be my only comment on this, so if you reply looking for a response it's not coming.

Poor practices take place in shops everywhere, every day for all sorts of reasons. The fact of the matter is if your in a production environment it matters where margins are razor thin and dead lines matter.

On the flip side if you're a guy in his garage on a Saturday morning just putting a chamber in barrel, you're going to grab the best fit twist drill and get the job done, you're not going to think "man I should get the correct tool for this because I'd hate to kill my $10 HSS drill".

Ya' I' am trying to figure out what any of this, that TRA has posted, has much of anything to do with chambering. Are we supposed to be impressed with all of his ramblings and BS, or what?

 

[Danny1788]

I bought one of these piloted core drill bits to try but haven't used it yet. Seems like it should work ok, what do you guys think?

 

[swd]

I bought one of these piloted core drill bits to try but haven't used it yet. Seems like it should work ok, what do you guys think?

View attachment 1005964

It should work fine but I would still true the hole up with a boring bar. A $5.00 drill works fine. You can do this cheap and done right or expensive and not any better.

I'm not trying to flame you, it's just not going to get you a better end result and unless you have something you need a nice piloted drill for I'd spend the money on something I really needed.

It takes less than 5 minutes to get this done right
with a $5.00 drill and a $30.00 boring bar that you probably already have. This is stupid simple, don't over complicate it.

 

[butchlambert]

tra, what kind of wore out machines do I have. I guess I was out when you came by. I'm glad you know how to push a button to start a machine. I guess your hospital clean shop is nice. Do you remember what kind of dirt floors I have in my home-rookie shop?
It appears that the folks that don't care for your manner are hacks in your estimation.
You said you have seen terrible machine work from some of our better shooters. Drop some names please.

 

[Danny1788]

It should work fine but I would still true the hole up with a boring bar. A $5.00 drill works fine. You can do this cheap and done right or expensive and not any better.

I'm not trying to flame you, it's just not going to get you a better end result and unless you have something you need a nice piloted drill for I'd spend the money on something I really needed.

It takes less than 5 minutes to get this done right
with a $5.00 drill and a $30.00 boring bar that you probably already have. This is stupid simple, don't over complicate it.

That's what I figure but was just going to give it a try and see what kinda results I get out of it. Already have the bushings so whats to lose right. Also have a few boring bars that should do the trick to clean up if need be.

 

[Patch700]

As of late whenever I am faced with a scenario such as this I find myself asking "What would Larry Potterfield do?" Soon followed by an epiphany not unlike a light being turned on by like larry himself..
I have even tried this with other tasks such as how do I get the oil filter removed from an 07 silverado without crushing it and spewing a quart of oil down my armpit...It works every time , don't ask me how but it does.

Try it... good luck

 

[John11-87]

I think this is just a simple question, that we made into a controversy. First off, you would never use a expensive, solid carbide drill to do this drilling operation, it would be a complete waste. Carbide drills are fairly expensive, and would be chipped out on corners after just a couple of parts, then would need to be sharpened. A HSS drill would be the best for this operation in my opinion, definitely isn't the best for the drill but in soft material (416SS or similar) it works just fine. If you were drilling hard miserable material such as 17-4 SS in certain conditions (H900 or similar), this would not work nearly as well.

Your HSS drill maybe wont follow the prepared hole perfectly... dont expect to hold .001 on the diameter, but if the drill is in good shape it should only drill .002 to .005 over the drill diameter (assuming the hole its following is dialed in fairly close). I would always recommend using a drill .010 to .030 smaller than your desired finish diameter, before boring, then finish reaming chamber.

Just my .02, Not a gunsmith, just a fellow "button pusher"