What tool / cutter setup do you use to turn rifle barrel shanks?

[LVLAaron]

What's your setup to turn rifle barrel shanks?

I have a number of CCMT style inserts and parting blades that I feel comfortable with... and they work. But I'm fairly new to this and wondering... If I were to set a barrel back 1 thread, or just wanted to take a few thou off a shoulder to clock a barrel - what tool would you use?

[Rubicon Prec.]

If you’re looking at insert tooling, a VBMT 331 insert in a -3* RH holder will do all OD barrel fitting work.

[WSnyder]

There's a zillion recommendations out there that will work well but I use the following:

ISCAR SWAPR-1414-06 Toolholder #3730108
ISCAR WPEX-060402IC908 Insert #5505996

These were long ago recommended by Speedy Gonzales for turning tenons. He originally recommended un-coated but ISCAR discontinued them and I switched to the IC908. I could tell no difference in the way they performed and the coated may even last longer. I'd have no problem skimming a few thousandths off with these. They cut easy and leave a great finish. I've been using them since at least 2008.

Oh, and thank you Speedy for a fine recommendation. Someone was listening

[Louis.J]

I just use HSS Steel bits that I have ground for all such related work.

[parshal]

I use these for cleaning up the shoulder and finish profiling.

[brickeyee]

I just use HSS Steel bits that I have ground for all such related work.

Carbide only works well when you have a solid enough setup to take deeper cuts.
HSS is more than adequate for typical gun work.
Carbide lives and dies by heavy cuts to remove heat in the chips.

Shaping and hardening (followed by some tempering) HSS is not all that difficult.
Barrel threads are not really all that large in the scheme of things.
Often around 8 per inch V threads.

Make sure the setup is solid.
Chatter really messes up smaller threads.

[WSnyder]

Carbide only works well when you have a solid enough setup to take deeper cuts. Disagree.
HSS is more than adequate for typical gun work. Okay, true.
Carbide lives and dies by heavy cuts to remove heat in the chips. Again, disagree.

People keep repeating this stuff over and over but it doesn't make it true. Once upon a time it might have been true but there are plenty of modern carbide inserts that work well with light cuts and are capable of removing small amounts of material at a time. They don't need to "take deeper cuts" nor do you need to take "heavy cuts to remove heat in the chips". I and many others have been using modern sharp carbide effectively for many years in smaller machines just fine. Now you may need to find the correct insert/s to do so but I assure you it exists and it has for quite some time.

[brickeyee]

Carbide only works well when you have a solid enough setup to take deeper cuts. Disagree.
HSS is more than adequate for typical gun work. Okay, true.
Carbide lives and dies by heavy cuts to remove heat in the chips. Again, disagree.

People keep repeating this stuff over and over but it doesn't make it true. Once upon a time it might have been true but there are plenty of modern carbide inserts that work well with light cuts and are capable of removing small amounts of material at a time. They don't need to "take deeper cuts" nor do you need to take "heavy cuts to remove heat in the chips". I and many others have been using modern sharp carbide effectively for many years in smaller machines just fine. Now you may need to find the correct insert/s to do so but I assure you it exists and it has for quite some time.

The grain in carbide, a sintered material, is also far larger than the atomic spacing in HSS alloyed steel.

Lighter weight equipment often lacks the rigidity to adequately support carbide cutters.
One of my many 'side jobs' was providing instrumentation for metal working setups that measured vibration under cutting loads.

We accounted for everything from bearing clearance vibration, to flex in the shaft of lathe tools.
Shorter reach is better.
We could detect the smoother operation of a 3-pase motor compared to a single phase motor.

[savet06]

I use a carbide CCGT insert from Sandvik - it has an .008 nose radius and a chip breaker. Leaves an excellent finish at around 700ish for the tenon, and then I crank it up to 1200 for the shoulder after I do a .004 (.008 total doc)plunge to make up for the radius of the nose.
HSS pre-ground arthur warner threading insert real slow like upside down away from the headstock in a mesa tools goose neck tool holder.
carbide insert made for aluminum on a boring bar for my cone and crown at about 1200rpm. No burrs and a mirror finish with a little viper's venom

[Louis.J]

Crown cut with HSS and polished for cast bullet benchrest use. Polishing is required to be able see the lube star left on the face of the muzzle.

[alinwa]

I've been fighting this same fight and had basically completely ditched HSS some yrs back (only after spending a couple grand on tool grinding equipment)

So I'm mostly a carbide insert guy now, feeling that with modern tooling the ONLY downside to the newer carbide inserts is that dratted radius on the end.

So I tried something else today

I was fitting a timed suppressor/brake and wanted contact at 4 points..... ie slip-fit on two radii and solid butt joints at two points with .001 of Paul Mauser style crush between front and rear abutments. And clean inside radius' at the rear abutment surface makes things wikkid easy.

I have a "pocket microscope" for inspection of porous finishes

I resurrected 6 beautifully ground (MANY hrs) 5/8 "threading bits" with looong slim offset tapers and spent a couple hours dressing edges and tips. Cut myself twice't. And made needle tips and razor edges which passed inspection under high magnification.

And promptly wrecked them.

You couldn't SEE the wrecks but when dialing in my offsets I got misreadings and under 60X could easily see chipped edges, knocked off corners.

So I'm back to carbide inserts, "smallest radius I can buy"........ and plunging that dadblamed inside radius

[brickeyee]

Did you harden and temper the HSS tools?
It makes a huge difference in their life.
The availability of diamond surfaces for sharpening hardened
HSS tools allows very fine edges to be created.

[alinwa]

Did you harden and temper the HSS tools?
It makes a huge difference in their life.
The availability of diamond surfaces for sharpening hardened
HSS tools allows very fine edges to be created.

No, I have never done this. And I do like it because it would allow me to do bulk grinding without a constant spray of water.

So please give me your opinion..... If I were to grind a bit to shape taking care to never let the points and edges get more than blue-hot. Then heat to a dull red and water quench...... then polish and anneal back to straw?

Anneal back to tan?

Brown?

Then stone/polish back to sharp edge using cold methods.....

is this what you propose?

[alinwa]

BTW, when I say "stone/polish" I do in fact use diamond-coated metal lapping boards. I have 12-15 large and flat diamond impregnated surfaces ranging from 320 grit to "6000" grit

I'm very adept at "sharpening" stuff....

[Louis.J]

Which grade of HSS did you actually have.
I personally have allot of time on my hands and now being retired also no in hurry to get anything done.
I have tried the carbide inserts but they are just not up to my own quality of workmanship.