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Local Smith with Lathe ?





7.62

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2019 Supporter
#1
I know it’s dumb, but I’d like to have a bull barrel turned down to a .gov profile and threaded for a standard A2 flash suppressor. Anyone know who could do that locally ?
 

NYECOGunsmith

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#4
You're looking at about three hours of shop labor rate for the machine work and set up. And as mentioned, then there is the finishing of the barrel by blueing, parking, whatever.
Make it four hours if you want all the turning marks polished out of the barrel while it's still in the lathe.

Depending on the barrel, most likely a lot cheaper to just buy another barrel.
 

TexasJackKin

Breathng Free, at last
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2019 Supporter
#5
That's a bigger project than you might think, I agree with others, probably better off buying a new barrel. You can sell the old one, or keep it and change back, if you should ever want to.
 

NYECOGunsmith

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#6
I should have mentioned that's 3-4 hours IF the lathe has a taper turning attachment, if not, it's gonna take twice as long and the smith better be good at step turning and draw filing to get the barrel to the correct taper per foot.
 

7.62

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2019 Supporter
#8
So I’m in Vegas to clarify that. Because the barrel is SS it doesn't need to be finished. I can’t find any .gov lightweight 20” SS profile barrels, well I think I found one online for like $350 + shipping. Sold out anywhere else I could find.

I wanted to build a 20” A1 style rifle with this SS barrel, just cause I think it’d be a neat. So in the spirit of being American and getting things done...I’m going to find a lawnmower engine, build some sort of turning jig and do it my own got damned self. The hell with you Debbie downers. Just not sure how to thread it but I’ll figure it out.

:poop: On me now.

And I’ve got an old vintage sewing machine I can tear apart for speed control. Stay tuned If you dare.
 

NYECOGunsmith

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#11
So I’m in Vegas to clarify that. Because the barrel is SS it doesn't need to be finished. I can’t find any .gov lightweight 20” SS profile barrels, well I think I found one online for like $350 + shipping. Sold out anywhere else I could find.

I wanted to build a 20” A1 style rifle with this SS barrel, just cause I think it’d be a neat. So in the spirit of being American and getting things done...I’m going to find a lawnmower engine, build some sort of turning jig and do it my own got damned self. The hell with you Debbie downers. Just not sure how to thread it but I’ll figure it out.

:poop: On me now.

And I’ve got an old vintage sewing machine I can tear apart for speed control. Stay tuned If you dare.
OK, lemme help ya out a bit here, I love Rube Goldberg contrapstions like this.

First off , that SS barrel is probably either a 410 or 416 Stainless, both are martensitic steels, and you need a SFPM (Surface Feet Per Minute) of between 100 and 250 depending on which one it is and the type of cutting tool you are going to use , HSS (High Speed Steel) brazed carbide, Ceramet, Cobalt, etc.

So if that barrel is what, close to an inch in diameter, most are around .936", then to get 100 SFPM on it you have to spin it at 3.82x 100 / .936 + 408 RPM (Revolutions Per Minute) call it one full inch and you get 382 RPM, if its a Contour 4 bull, at 1.150", then 332 RPM, a Contour 5 at 1.250" would be 305 RPM.

If the tool you intend to use is gonna need a higher SFPM, then at the maximum 250 SFPM range you would be looking at 1020 RPM to 764 RPM for the above barrel diameters.

We won't bother with calculating chip load on the cutting tool, we'll just plunge right in and build you a barrel turner that will handle the above.

So, you're gonna need a 3 HP or larger lawnmower engine, with a throttle control, and a means to guesstimate the RPM to get into the above ranges , that's easy, just put a white dot on the crankshaft of the engine, start it, bring up the stopwatch app on your phone, and count how many times the white dot goes by at various throttle settings until you figure out which one will work for ya.

Now what are ya gonna do about a chuck? Too much work and expense to use one of those.

So we'll go old school with a face plate. Take a 10" diameter or so disc brake rotor and weld it onto the end of the lawn mower engine crank shaft, try to get it as perpendicular to the end of the shaft as possible.

For a tail stock, shucks, a junk of 2x4 with a bit ol nail through the end of it will work for a dead center to go into the muzzle of yer barrel.

Mount that lawn mower engine and face plate onto a length of 2x12, take the barrel and butt the chamber end of it up against the face plate, as close to the center as possible, and lash it there with wet rawhide boot laces.
While the rawhide is a drying and tightenin down, stuff the nail on that chunk of 2x4 into the muzzle an inch or so, and then nail the 2x4 to the 2x12 for yer tail stock.

Now gitcha a good old 14 inch long course bastard file, doesn't need to have a handle on it, take one last swig of yer beer, hand the beer to yer buddy, start that 6.5 HP Briggs and Stratton up, pick up the file, turn and say "Hey Ya'all, what this", lean over the barrel, rev the Briggs and Stratton up to full throttle (to hell with the SFPM, I want to Get'er done!" and go to filing on that barrel till you get it down to the right diameter and taper. Or until you have to leave fer the hospital to have yer injuries attended to, whichever comes first.

Now if't yuh've made it this fer, here's the next step.

Have a 3 cornered file handy when yer done with the turnin down, they's all 60 degree angles yuh know, and perfect for making threads, and while that barrel is a spinnin, touch that file down at a helix angle of 1.302 degrees, angled towards the Briggs and Stratton of course, and with that thing reved up agin, commence to cuttin the 28 threads per inch on that turned down section, until you get a thread depth of roughly .0267 inches, stop that B&S and pull the nails outen the 2x4 tail stock, and try yer flash suppressor on fer size. If she fits, fine and dandy, it not, nail that tail stock back down and go some more till she does. No need to worry about it fittin too tight, the carbon blow by of a few hundred shots, plus the metal flakes from the baffle strikes will eventually fill in the gaps and tighten it right up fer ya.

See, you dint need that thar sewing machine a'tall.

Texas Jack Kin, ya'all worked at the machinist trade more recently than I have, did I miss anythin?
 

7.62

Obsessed Member
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2019 Supporter
#13
Now we’re talking (y). In my time I’ve built some crazy stuff out of the need to get the job done. Do I think this might work...you betcha. Thank you for taking the time, over the next month or so I’ll post some pics and check in.

OSHA.....damn near lost my CCW because I got a little physical with one of those fine gentlemen maybe 10 years ago, had to write a written apology to everyone involved so save my ass.....yeah I’m sure they’d love this and my home made muncher for corn stalks....:eek:

Anyone got a side pulley Briggs and Stratton they want to sell ?
 

titanNV

NRA Endowment Member
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#14
So I’m in Vegas to clarify that. Because the barrel is SS it doesn't need to be finished. I can’t find any .gov lightweight 20” SS profile barrels, well I think I found one online for like $350 + shipping. Sold out anywhere else I could find.

I wanted to build a 20” A1 style rifle with this SS barrel, just cause I think it’d be a neat. So in the spirit of being American and getting things done...I’m going to find a lawnmower engine, build some sort of turning jig and do it my own got damned self. The hell with you Debbie downers. Just not sure how to thread it but I’ll figure it out.

:poop: On me now.

And I’ve got an old vintage sewing machine I can tear apart for speed control. Stay tuned If you dare.
all good buddy!
I wonder if someone like Spinta or another custom builds to your spec. That might be another avenue to pursue.
 

NYECOGunsmith

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Staff member
Moderator
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2019 Supporter
#15
Now we’re talking (y). In my time I’ve built some crazy stuff out of the need to get the job done. Do I think this might work...you betcha. Thank you for taking the time, over the next month or so I’ll post some pics and check in.

OSHA.....damn near lost my CCW because I got a little physical with one of those fine gentlemen maybe 10 years ago, had to write a written apology to everyone involved so save my ass.....yeah I’m sure they’d love this and my home made muncher for corn stalks.
Anyone got a side pulley Briggs and Stratton they want to sell ?
No B&S handy, but you could substitute that rusty old 327 Chevy sitting over there in the weeds, bonus, the flywheel is still on it!
 

Harley

Obsessed Member
Forum Supporter
#17
OK, lemme help ya out a bit here, I love Rube Goldberg contrapstions like this.

First off , that SS barrel is probably either a 410 or 416 Stainless, both are martensitic steels, and you need a SFPM (Surface Feet Per Minute) of between 100 and 250 depending on which one it is and the type of cutting tool you are going to use , HSS (High Speed Steel) brazed carbide, Ceramet, Cobalt, etc.

So if that barrel is what, close to an inch in diameter, most are around .936", then to get 100 SFPM on it you have to spin it at 3.82x 100 / .936 + 408 RPM (Revolutions Per Minute) call it one full inch and you get 382 RPM, if its a Contour 4 bull, at 1.150", then 332 RPM, a Contour 5 at 1.250" would be 305 RPM.

If the tool you intend to use is gonna need a higher SFPM, then at the maximum 250 SFPM range you would be looking at 1020 RPM to 764 RPM for the above barrel diameters.

We won't bother with calculating chip load on the cutting tool, we'll just plunge right in and build you a barrel turner that will handle the above.

So, you're gonna need a 3 HP or larger lawnmower engine, with a throttle control, and a means to guesstimate the RPM to get into the above ranges , that's easy, just put a white dot on the crankshaft of the engine, start it, bring up the stopwatch app on your phone, and count how many times the white dot goes by at various throttle settings until you figure out which one will work for ya.

Now what are ya gonna do about a chuck? Too much work and expense to use one of those.

So we'll go old school with a face plate. Take a 10" diameter or so disc brake rotor and weld it onto the end of the lawn mower engine crank shaft, try to get it as perpendicular to the end of the shaft as possible.

For a tail stock, shucks, a junk of 2x4 with a bit ol nail through the end of it will work for a dead center to go into the muzzle of yer barrel.

Mount that lawn mower engine and face plate onto a length of 2x12, take the barrel and butt the chamber end of it up against the face plate, as close to the center as possible, and lash it there with wet rawhide boot laces.
While the rawhide is a drying and tightenin down, stuff the nail on that chunk of 2x4 into the muzzle an inch or so, and then nail the 2x4 to the 2x12 for yer tail stock.

Now gitcha a good old 14 inch long course bastard file, doesn't need to have a handle on it, take one last swig of yer beer, hand the beer to yer buddy, start that 6.5 HP Briggs and Stratton up, pick up the file, turn and say "Hey Ya'all, what this", lean over the barrel, rev the Briggs and Stratton up to full throttle (to hell with the SFPM, I want to Get'er done!" and go to filing on that barrel till you get it down to the right diameter and taper. Or until you have to leave fer the hospital to have yer injuries attended to, whichever comes first.

Now if't yuh've made it this fer, here's the next step.

Have a 3 cornered file handy when yer done with the turnin down, they's all 60 degree angles yuh know, and perfect for making threads, and while that barrel is a spinnin, touch that file down at a helix angle of 1.302 degrees, angled towards the Briggs and Stratton of course, and with that thing reved up agin, commence to cuttin the 28 threads per inch on that turned down section, until you get a thread depth of roughly .0267 inches, stop that B&S and pull the nails outen the 2x4 tail stock, and try yer flash suppressor on fer size. If she fits, fine and dandy, it not, nail that tail stock back down and go some more till she does. No need to worry about it fittin too tight, the carbon blow by of a few hundred shots, plus the metal flakes from the baffle strikes will eventually fill in the gaps and tighten it right up fer ya.

See, you dint need that thar sewing machine a'tall.

Texas Jack Kin, ya'all worked at the machinist trade more recently than I have, did I miss anythin?
Piece of cake! Should have it all set up in no more than about an hour!
 

nlvmike

Just one more
Forum Supporter
#18
As fun as your project sounds, I would pass on all that and call Burt Taylor, or another competent smith and see what it would take to get what you want. I've had a few turned down to get exactly what I want, and it's been worth it.
 

NYECOGunsmith

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2019 Supporter
#19
Ya know guys, when I fork up, I fork up to the max.
I want to apologize to 7.62 and the rest of ya'all for my narrow minded approach to his desire to recontour that stainless steel bull barrel.

My only explanation is that Attack Cat was sick for 3 days (she's fine now, must have been somebody she ate....) and I was up for three days straight looking after her when I answered 7.62's questions, and I focused solely on answering his questions with a manual lathe in mind.

What I should also have offered up for his consideration was finding a shop with CNC machining centers, like New Frontier Armory for example, who might just have a barrel contour program on one or more of their machines, in which case I would suggest stuffing that stainless steel bull barrel in there as the blank, and having the CNC center recontour it, shouldn't take more than 30 minutes, probably 15 or less for a CNC center with the right G code program in it to get it done, I would guess that method would run $100 or less.

There is still the issue of the stresses that will be installed in the barrel with the recontouring, but no matter how the work is done, manual lathe or CNC, those will be present when the work is finished and will be dealt with at that time.

Sorry I let ya down 7.62, my apologies for being so narrow minded and not considering the other machining option.
I'm old, get used to it, it's only gonna get worse I am afraid!