HSS or Carbide for barrel threading

[Zebra13]

An old toolmaker friend suggested I thread this way when I first started and I have done it since.

Pete

Pete,

Yup...pretty much how dad explained it to me.

If a big thread relief freaks anybody out, think about Butch's post where he talks about stopping the tool, and then stopping the lathe. This results in a wee 60 degree groove up next to his shoulder, in effect becoming a thread relief groove of sorts. Threading with the tool upside down, you make the same groove with the threading tool next to your shoulder. This is home. Set your DRO/Travel-a-Dial/indicator/carriage stop to "zero" at this point. Thread out from this point, returning to "home" or "zero" prior to making another pass, deepening your groove as you go. You'll end up with a thread that looks just like Butch's, just accomplished a different way, and not having to thread into a shoulder.

I'd be willing to bet some folding money that that wee groove makes no practical difference in the action/barrel joint integrity.

Justin

 

[keithcandler]

threading groove

Threading groove will only hurt your pride a little.

A more practical aspect of the groove will be if/when you sit back a barrel. You will then have a groove in the middle of your tenon, which will hurt your pride a little more.

If your mind has troubled issues with threading toward a shoulder, then sit up a travel dial. Establish your target number to disengage, and with a little practice you will hit it within .002 if not right on the number. You can make a groove with the tip of the threading tool to the double depth of the thread pitch when you first start. When you are finished threading, this v groove to the double depth of thread is hard to see to a novice's eye, and if you have to pick the thread up later on a sit back, the tenon is not an unsightly mess.

I used to use Warner hss inserts, now use Carmex after a fellow board member sent me pics of his threads that look like Gene's. For a person using a T15 grade HSS threading bit or insert, it is hard to imagine just how long a carmex insert will last. I also grind my own 3/8" alloy bits from Tantung G, Stellite, Armaloy, and Rexalloy which are hard to dull also. Grinding bits is a secondary hobby when there is time. The bits ground from the Alloy bits will need touching up around every two years on a Harbor freight belt sander, quick and easy.

The alloy bits contain from 37% to 49% cobalt, hard to kill an edge on them. I have not had trouble with them chipping over the years. There is a guy in N.C. that grinds bits for machinists and does a heck of a job if any are interested, send me a pm and I will give you his contact info. Even bits made from WKE 45 are excellent. These larger bits absorb a lot of heat and stay sharper longer than normal hss.

Some machinists will use a large 5/8" threading bit to make a final cut on a tenon into a corner as the radius on these bits are very small. This larger threading bit with the bottom of the front ground round makes for one heck of a crowning bit, also.

 

[Engrbill]

Do it like Joe Pie

Upside down and backwards with TC insert. When you do this you can run TC insert FAST from a hard stop with no Chicken Groove. -----Bill

 

[Ben H]

Thread Relief Groove and Width?

If using a thread relief groove, what is the recommended depth and width? Is a cut off/grooving tool best for this?

Thanks,
Ben H

 

[RATGONIFER]

I'm NOT a machinist nor a gunsmith but I've been doing this game a very long time and I build one to several rifles or swap barrels each year. I am/was a welder/mechanic by trade and not particularly nervous by any stretch of the imagination...been shot at and missed, and sh** at and hit ...more times than I care to recall...

BUT...when I started to learn the lathe and how to thread I got so jumpy NO ONE, not even my dog, would get near me. I soon learned that trying to get all those moves coordinated and produce a nice thread wasn't in the cards. All this was "learning by myself" from books, online many years go, video tapes and LOTS of practice.

Times have sure changed...but one thing HASN'T...I STILL can't thread a barrel on a manual without ending up with some kind of groove next to the shoulder. Most of the time it's just a thread groove minor dia OD...sometimes I clean it up with a 0.032" cutoff tool to the bottom of the thread...but most of the time I just leave the groove there...I haven't seen any problems anywhere and my finished barrels will do bugholes most of the time...doesn't matter if I use a barrel nut or not.

I also started with HSS threading bits from Grizzly, the same company that I bought my 4003 lath from...but soon went to carbide...again, NO ONE told me I was doing "something wrong".

I've watch You-Tubes by the hour and learn a "lesson a minute" and get all jealous looking at how totally neat the newer manual machines and CNC machines are, but I think my latest 28 Nosler project will be my last...can't stop Mother Nature's ravages and I'm just getting tired of doing this "Thing".

SO...right or wrong I will continue to thread MY WAY, using CARBIDE and forget the rest...I don't care a ratza** whether I'm right or wrong, just that my threads AREN'T doing the wibbly-wobbly and the barrel isn't pointing off to la-la land.

I just watched a YouTube about inverting the tool and threading from LEFT to RIGHT shoulder to end...and one on setting the tool right side up on the opposite side of the lathe threading from LEFT to RIGHT...I HAVE to try that...I need my coffee in the morning, but I have to wait till afternoon to thread because I get coffee nerves after 5-6 cups and go all twitchy...going from left to right will solve that little hiccup.

ALSO...along with all this "new larn'n', CNC is different than manual and has different tool post setups from what I learned...SO...things have changed, new lessons learned and being FLEXIBLE in approaching machining is more important than "BEING RIGHT".

Keep making chips.

 

[BG Gunworks]

I'd been using HSS Warner inserts (an amateur quality grind-your-own) for years, just bought the carbide tooling a few weeks ago.

I'm pissed at myself for waiting too long to switch.
I run double the DOC that I could with HSS (South Bend), with very low feed rates and higher rpm.
Surface finish is GREAT at heavy cuts, not so much on skim cuts but still better than HSS.
DCMT, VBMT triangles get into shoulder undercuts better than any HSS I've used...
Warner is great, but I don't get the longevity of carbide- AND the carbide is cheaper.
Hell, I don't know if it's supposed to be required, but I'm cutting threads bone dry and they're great with no chatter.

I got some full-profile threading inserts that I'm getting ready to try, bit of a different animal.

 

[RATGONIFER]

Full profile carbide

I bought 4 full profile bits 7-8 years ago...2 for 16 tpi and 2 for 20 tpi, plus extra holders. I marked them with a white paint stick so they are easy to spot. They seem to do all the work themselves an come out great, no mucking about with threading files, files turning flats or running a threading die for the last pass.

I've done about a dozen barrels each so far on the first bits and cant's see any wear.

Someday someone will get a great deal on Ebay on all the threading bits covered with cob webs in boxes stuck back behind all the "useful" tools.

 

[Wildcatter]

I bought 4 full profile bits 7-8 years ago...2 for 16 tpi and 2 for 20 tpi, plus extra holders. I marked them with a white paint stick so they are easy to spot. They seem to do all the work themselves an come out great, no mucking about with threading files, files turning flats or running a threading die for the last pass.

I've done about ls.

Turning flats, threading die for last pass??? Not there yet boss!!!

 

[RATGONIFER]

'Zat right, Wildcatter...Really...that statement was partially tongue in cheek...I forgot this is BENCHREST and that sorta stuff isn't allowed. It's also know as "knowing your machines". In todays world of CNC and fancy extremely precise and accurate machines all you have to do is punch some buttons and hit it perfectly.

I have a cheap Chinese 12-36 gear head knockoff and I know what it can and cant do...so waving a file, threading file or threading die sometimes is the ONLY way to "get the job done". Bossman don't care about hearing "I can't"...I CAN'T is the fastest way to go down the road with your final check in your pocket that I know of.

"Not there yet" is elitism for "you dumb...." Heartwarming to say the least.

I guarantee I will do whatever is necessary to "get the job done" and my rifles shoot WELL below 0.500" all the time...Not up to benchrest standards of today but not too far off those standards of the late 50's to late 60's....I remember when 2's and 3's took home all the bacon.
Times DO change and not always for the best.

If I need a file to hand fit a barrel snugly then guess what!!!!

Wish I DID have a more accurate and precise lathe or even a CNC lathe, but that didn't happen.

By the way...my local gunsmith and mentor did me a 250 AI in a Rem 788 way back in the late 60's. He faced the receiver, squared the threads, faced and squared the bolt then lapped it in and threaded/chambered/crowned the barrel, ALL for the price of the barrel...that was done that way back in the day, or at least for a while. He hand fitted the barrel to the receiver, WITH a threading file AND FLAT BASTARD file and I watched him do the whole process. That 24", #2 contour,straw, Douglas air gauged barrel shot in the mid 1's from day one for 3 shots then opened up slightly for two more. It still will shoot in the low 4's today, when I can hold it, after who know how many rounds, varmints, deer, antelope, coyotes, and Elk and one Brangus bull.

Have a nice day.

 

[Richard]

I have seen

worn lathes cut good threads, chi-com lathes that cut decent threads.
Three measurements that will get you on track. major dia, pitch dia, and minor dia if making a thread relief.
BTW snug threads doesn't make a bbl shoot better, having a good setup that runs true does make for a bbl that will shoot to it's potential.
I seriously doubt that very many here use cnc equip for their work. Could be wrong on that though.
There is some very good info out there. Jackie Schmidt, Mike Bryant (and others) has posted some good pointers over the years and I think even some videos.

Richard

 

[Rubicon Prec.]

Carbide laydown at 750 RPM pulling out .010” before the leading edge of the insert touches the shoulder.

 

[Richard]

Cnc

at it's finest

 

[alinwa]

'Zat right, Wildcatter...Really...that statement was partially tongue in cheek...I forgot this is BENCHREST and that sorta stuff isn't allowed. It's also know as "knowing your machines". In todays world of CNC and fancy extremely precise and accurate machines all you have to do is punch some buttons and hit it perfectly.

I have a cheap Chinese 12-36 gear head knockoff and I know what it can and cant do...so waving a file, threading file or threading die sometimes is the ONLY way to "get the job done". Bossman don't care about hearing "I can't"...I CAN'T is the fastest way to go down the road with your final check in your pocket that I know of.

"Not there yet" is elitism for "you dumb...." Heartwarming to say the least.

I guarantee I will do whatever is necessary to "get the job done" and my rifles shoot WELL below 0.500" all the time...Not up to benchrest standards of today but not too far off those standards of the late 50's to late 60's....I remember when 2's and 3's took home all the bacon.
Times DO change and not always for the best.

If I need a file to hand fit a barrel snugly then guess what!!!!

Wish I DID have a more accurate and precise lathe or even a CNC lathe, but that didn't happen.

By the way...my local gunsmith and mentor did me a 250 AI in a Rem 788 way back in the late 60's. He faced the receiver, squared the threads, faced and squared the bolt then lapped it in and threaded/chambered/crowned the barrel, ALL for the price of the barrel...that was done that way back in the day, or at least for a while. He hand fitted the barrel to the receiver, WITH a threading file AND FLAT BASTARD file and I watched him do the whole process. That 24", #2 contour,straw, Douglas air gauged barrel shot in the mid 1's from day one for 3 shots then opened up slightly for two more. It still will shoot in the low 4's today, when I can hold it, after who know how many rounds, varmints, deer, antelope, coyotes, and Elk and one Brangus bull.

Have a nice day.

I guess we all read differn't

I honestly thought Wildcatter was complimenting you

 

[webphut]

If you call on the telephone, MSC INDUSTRIAL SUPPLY, they will not only make a recommendation, but because you are just learning to single point, they will actually teach you about it and also send you one of those 1200 page catalogs in the mail. As for carbide, there are some really trick tools on the market, but because you are new, use HSS tool bits. It will drive you crazy when you first learn, but it will better insight in single pointing.