Another neck turning thread.

Jim, IIRC Jackie Schmidt, on this board and lives in Houston has a P&W about that size and would be a good person to contact. He is well versed on machining benchrest quality barrels.

With that long headstock you will have to make at least three bushings for the outboard end of the barrel.

The first bushing will need to be a good slip fit in the spindle bore and the ID will need to be to match the barrel breech OD. The first operation will be to use that bushing to stabilize the
breech end in the headstock while you prepare the muzzle end. With the barrel held in your 4-jaw chuck and the breech end stabilized as above, dial in the muzzle bore. You can then turn a short fit 1/2" or so to a diameter to fit the ID of the next bushing below. (Say 1/2" OD X 1/2" long.)

The second bushing, same OD and the ID will be to fit whatever size you choose to turn the short fit described above. You will then turn the barrel around and indicate the end to be chambered with this bushing stabilizing the muzzle end in the headstock.

The third bushing, same OD, and the ID threaded to fit the barrel tenon thread. After chambering and threading turn the barrel back around again, you will machine off that muzzle snub, reindicate the muzzle bore and crown the barrel.

Yes, you will be turning the barrel around at least 3 times with that machine but the 3 time swap is also required on most lathes like the SB Heavy 10 which has a short headstock.
 
JerrySharrett said:
Jim, IIRC Jackie Schmidt, on this board and lives in Houston has a P&W about that size and would be a good person to contact. He is well versed on machining benchrest quality barrels.

With that long headstock you will have to make at least three bushings for the outboard end of the barrel.

The first bushing will need to be a good slip fit in the spindle bore and the ID will need to be to match the barrel breech OD. The first operation will be to use that bushing to stabilize the
breech end in the headstock while you prepare the muzzle end. With the barrel held in your 4-jaw chuck and the breech end stabilized as above, dial in the muzzle bore. You can then turn a short fit 1/2" or so to a diameter to fit the ID of the next bushing below. (Say 1/2" OD X 1/2" long.)

The second bushing, same OD and the ID will be to fit whatever size you choose to turn the short fit described above. You will then turn the barrel around and indicate the end to be chambered with this bushing stabilizing the muzzle end in the headstock.

The third bushing, same OD, and the ID threaded to fit the barrel tenon thread. After chambering and threading turn the barrel back around again, you will machine off that muzzle snub, reindicate the muzzle bore and crown the barrel.

Yes, you will be turning the barrel around at least 3 times with that machine but the 3 time swap is also required on most lathes like the SB Heavy 10 which has a short headstock.
Click to expand...

Jerry,

I will get in touch with Jackie whenever I get the lathe in here and start getting it cleaned up and ready to start up. In the meantime I'm trying to get a visual and get my head wrapped around the bushing thing, I think I've got the idea but I'll keep cooking my brain a little thinking on it.

One thing I was wondering, because the outboard end of the spindle bore is so tight on the bottom, would it be a reasonable idea to turn a taper onto a length of trued cylinder to make a spider that will self align in the spindle bore to hold the barrel, that way it will get far enough past the clearance issues to function correctly?
 
Jim Cox said:
Jerry,


One thing I was wondering, because the outboard end of the spindle bore is so tight on the bottom, would it be a reasonable idea to turn a taper onto a length of trued cylinder to make a spider that will self align in the spindle bore to hold the barrel, that way it will get far enough past the clearance issues to function correctly?
Click to expand...


(So tight on the bottom?)

Jackie will be best to answer that since I'm not really familiar with the P&W spindle bores. There will be multiple ways to skin that calf.
IIRC, Jackie ran a reamer through his lathe spindle for some reason. It may have been to true it up???
 
I'm moving it here on Friday, and getting it leveled and set up, draining oil and flushing the system out, pulling the carriage off and cleaning/degreasing all the ways and gears, checking out everything the manuals illustrate, topping off the lubrication, checking the wiring, hooking up the 3 phase convertor and working on firing it up for the first time. Trying to track down a good quality tool post as well, I'm trying to get an American made one. It just seems wrong to put Chicom stuff on an American workhorse like this lathe. I'd definitely be curious as to why he ran a reamer through the spindle, and where he found a reamer that size, how he did it, etc.

Jim


ETA: Tight on the bottom of the spindle, the change gear housing sticks out right there and makes for a clearance issue for a couple inches.
 
Jim Cox said:
Chicom stuff on an American workhorse like this lathe. I'd definitely be curious as to why he ran a reamer through the spindle, and where he found a reamer that size, how he did it, etc.

Jim


ETA: Tight on the bottom of the spindle, the change gear housing sticks out right there and makes for a clearance issue for a couple inches.
Click to expand...

I agree entirely about the Chicom stuff. I am thinking he ran a reamer through the spindle shaft to make it a more consistent diameter from end to end and that would allow for closer fitting bushings similar to the ones I mentioned above. Running a reamer through the spindle bore certainlly would not "straighten" the bore but just make it more precise in diameter.

Like I mentioned earlier, Jackie would be better qualified on fitting the lathe you just bought for rifle barrel fitting.
 
JerrySharrett said:
I agree entirely about the Chicom stuff. I am thinking he ran a reamer through the spindle shaft to make it a more consistent diameter from end to end and that would allow for closer fitting bushings similar to the ones I mentioned above. Running a reamer through the spindle bore certainlly would not "straighten" the bore but just make it more precise in diameter.

Like I mentioned earlier, Jackie would be better qualified on fitting the lathe you just bought for rifle barrel fitting.
Click to expand...

I put up a thread over at practicalmachinist, hopefully I'll get some good input over there, I really appreciate the help you've given me.

Now that I have a lathe, would it be more appropriate to use a collet to hold brass and use HSS tools to turn necks? I can't imagine a handheld tool matching the precision of a 5,000lb lathe with a sharp cutter and rigid tool post. Come to think of it, I could probably grind a cutter to make a cut just touching the shoulder at 30º and turn the necks in one pass, turning at about 80ish RPMs, thoughts?

Jim
 
Jim Cox said:
I put up a thread over at practicalmachinist, hopefully I'll get some good input over there, I really appreciate the help you've given me.

Now that I have a lathe, would it be more appropriate to use a collet to hold brass and use HSS tools to turn necks? I can't imagine a handheld tool matching the precision of a 5,000lb lathe with a sharp cutter and rigid tool post. Come to think of it, I could probably grind a cutter to make a cut just touching the shoulder at 30º and turn the necks in one pass, turning at about 80ish RPMs, thoughts?

Jim
Click to expand...

To get good results neck turning on an engine lathe you need to turn a mandrel each time and you still don't get great results because a lathe, even a 10EE or Hardinge HV-L must have a working clearance for the spindle to turn. Besides that is overkill and dangerous!!
 
Okay, then I will definitely use the JACO instead of the lathe. Good info. Thanks!

Jim
 
Before you get hot and bothered about all of this, contact Jackie at RG Schmidt and Sons. He will be very helpful to you and in a no BS way. They are a very large shop that makes, straightens, or repairs the shafts for large boats. They have a multitude of machinery. Jackie has shown on this forum how he neck turns in a lathe. You can go to Mike Bryant's website and see how he does it in a lathe. I turn mine in a lathe with a collet, but use a Pumpkin neck turning tool. If I were cutting them with a lathe, I sure wouldn't use a collet.
 
Butch Lambert said:
Before you get hot and bothered about all of this, contact Jackie at RG Schmidt and Sons. He will be very helpful to you and in a no BS way. They are a very large shop that makes, straightens, or repairs the shafts for large boats. They have a multitude of machinery. Jackie has shown on this forum how he neck turns in a lathe. You can go to Mike Bryant's website and see how he does it in a lathe. I turn mine in a lathe with a collet, but use a Pumpkin neck turning tool. If I were cutting them with a lathe, I sure wouldn't use a collet.
Click to expand...

Thank you for the advice Butch, I will make sure to give him a buzz when I get this behemoth into the garage tomorrow. For now my biggest concern is getting it safely in place and leveled up.

If you were to turn on a lathe, how would you go about it personally? I like to hear as many opinions as I can get.

Jim
 
I will continue to turn mine as I now do it. I believe Jackie and Mike turn a spud in the chuck? collett?, and then press the brass on the spud. I think Mike uses a shell holder in the tailstock. He uses that to press the brass on to the spud and does his turning. The shell holder is used to pull the brass off the spud. The spud is a throwaway as you need to turn one each neck turning session.
 
Butch Lambert said:
Before you get hot and bothered about all of this, contact Jackie at RG Schmidt and Sons. He will be very helpful to you and in a no BS way. They are a very large shop that makes, straightens, or repairs the shafts for large boats. They have a multitude of machinery. Jackie has shown on this forum how he neck turns in a lathe. You can go to Mike Bryant's website and see how he does it in a lathe. I turn mine in a lathe with a collet, but use a Pumpkin neck turning tool. If I were cutting them with a lathe, I sure wouldn't use a collet.
Click to expand...

Hi Butch

My question is, how many cuts do you make on the brass with the Pumpkin?

Later
Dave
 
Butch Lambert said:
I will continue to turn mine as I now do it. I believe Jackie and Mike turn a spud in the chuck? collett?, and then press the brass on the spud. I think Mike uses a shell holder in the tailstock. He uses that to press the brass on to the spud and does his turning. The shell holder is used to pull the brass off the spud. The spud is a throwaway as you need to turn one each neck turning session.
Click to expand...

I've already told him to contact Jackie since Jackie has a P&W almost like the one Jim just bought.

A case mounted on a preturned stub arbor. Make the arbor in 3 steps, the first step is about 0.238: X 1/4" long and used to guide the case onto the arbor. The second diameter is cut to exactly the diameter of your bullet (usually 0.2435 x 1/4" long. Making this fit this size assures that what size you turn the neck, the loaded round is exactly that diameter. The third diameter (the one nearest the chuck) is just for tool over run, about 0.260 x 1/4" long.
(Oh, that ugly looking threaded part is where I made this arbor out of an old Grade-8 bolt)

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This is a tool used with the tailstock to press the brass on the arbor and it has a slide-hammer to pull the brass off. The blue thing is a K&M brass holder.

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This is the turning operation, The 0.0001" dial indicator measures the actual movement of the turning tool since most lathe dials are in 0.001" divisions.

V
2lnz58p.jpg


BUT-we have tried this on a H 10 and a 10EE and still get better results with a hand held turner-roughing with a Sinclair and finishing with a K&M, Punpkin or Stiller.
 
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Well, got the lathe into my garage…3 feet from being set and in the door, a pipe crushed and it high centered, tilted, and crashed into the concrete. Lathe is scrap metal, hit the carriage so hard it popped off the ways, carriage handwheel shattered, cross slide handwheel is now at a 45º angle to the bed. Thanks to everyone that gave me help and advice, it's much appreciated. Looks like I'm going to be using my Versa Vise and JACO for the foreseeable future to turn necks.

Jim
 
If the carriage/crossslide popped off it sounds like the carriage was not strapped down by its bottom rails.

Did it bend the feed and control rods that run front to back?

A lathe of that size can not be hurt too bad. Post a couple fo pictures.
 
Looks like the carriage and cross slide are still in place. Just a couple of bent shafts, the cross slide shaft and carriage shaft.
If none of the major castings are broke, you can find replaccement shafts for the other.

Oh, and 10 bags of kitty-litter.
 
On second look the carriage shaft may not be bent, just the handwheel broke.

This shows an important reason to wear safety shoes when millrighting!!
 
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