single point threading muzzles vs die cut

[Whiterabbit]

So, I bought a die anyways in 5/8-24 to match my tap. Had to, it was in a machinist's toolbox in an antique store. Bought it with some punches, a tenth's dial indicator, a vintage file, etc etc etc for $13. How DO you go wrong!

Chances are good I'll never use it for anything except threading the muzzle of some aluminum bar stock for fun.

But really, any reason NOT to use a die for a real muzzle threading project as opposed to single point cutting?

[KCSO]

IF you have a tailstock die holder and IF you think you can get your threads started straight enough it will work. I want threads on the muzzle straight as I can get them under .0005 so I always dial in the muzzle and the breech in the 4 jaw and the spider and then at least start the threads with single point, then I might finish with a run by hand with the die just to clean up and check the threads.

[MtGun44]

Lathe cut threads WILL be aligned with the end if you use a good alignment
pin in the muzzle, do a cleanup cut, so now the OD is concentric to the bore,
for certain. Die can be off center if OD is off center or canted very easily.

Bill

[nhrifle]

With a good fitting bore pilot to guide the die it can be done, but for the best results a lathe is definitely the way to go.

[Whiterabbit]

I just don't trust my tooling to get me to 100%. But frankly, I have every confidence my tooling can go to 80%. Any issues making several passes on the lathe, then finishing with the die BY HAND? Or is it still best if considering that method to run the die in via homemade tailstock die holder?

[theperfessor]

It will be hard to line a die up on a partially cut thread. This is NOT the same as just cleaning up the burs on a fully cut thread. I would always opt for lathe cut threads and then use a thread file to clean up the threads.

[leftiye]

I just don't trust my tooling to get me to 100%. But frankly, I have every confidence my tooling can go to 80%. Any issues making several passes on the lathe, then finishing with the die BY HAND? Or is it still best if considering that method to run the die in via homemade tailstock die holder?

In all cases what makes a die go crooked is too much metal to be removed. What you advocate doing is what I always do, Get the pitch diameter (get the thread) within a few thousandths of being done before using the die to finish. You want the die to start easily, and not require massive force to cut. Any tooling that you might have to support the die as straight is good to use. It can still go crooked. Fine threads like muzzle brakes require only one or two passes on the lathe before being within range of the die.

[W.R.Buchanan]

I always look at it like "if you are threading the part on the lathe, why not go all the way?" The back side is if you don't have anyway to measure the PD of the thread then doing a partial on the lathe and finishing with a die is an acceptable way to do this operation.

One thing that must be present either way is a thread relief at the end of the thread so that the pilot threads of the die can go beyond the end of the threads. Another way is to flip the die around and finish the last little part of the thread by running the die in reverse.

To start a die strait on a lathe with a tailstock you use the front face of a drill chuck to seat the die on your 45* chamfer and turn the die while keeping pressure on the chuck. This operation can go bad so you have to pay attention. But on small rods and the like it is pretty easy.

YOU ALWAYS use a 45* chamfer because this is the way threads are designed. The lead of the thread starts on a 45* angle and produces less of a knife edge on the lead thread. When people try to use a 60*chamfer thinking that since the thread is 60* the lead should be 60* as well, (and we all have done this!) what you create is a lead that is very easily damaged which leads to other problems.

I also have a die holder that consists of a knurled round section the holds a die and then a 5/8" shaft with a hole all the way thru it, that goes into a tool holder. The tool spins freely in the holder. You run the tool onto the rod you are threading and hang onto the knurls while the machine is running slowly. When you get to the desired depth you release the knurled section and the tool turns with the work. Then you reverse and grab the knurls again and the tool backs off the work. Flood oil is required unless you want bad threads. This is a simple and very nice way to make smaller threaded rods.

I also have a tap holder that does the same thing. The limit with it is #6 threads.
Both of these tools are limited to like #10 and smaller threads simply because you can't hang onto the tool with larger threads. Unless you are the HULK! You can't hold onto larger threads because there is just too much turning force, and plus that your hand is going to be oily.


I made both of these tools many years ago and for doing small parts they work very well. Anyone who owns a lathe can make them, but you will need something like a KDK Tool Post with the 5C tool holder or a block with a 5/8" hole thru it to mount the die holder.

Here's some pics of the tools.

Randy

Also when using a tap on the lathe you use a lathe center and put the tap in between the center and the chamfer of the hole. This inures you get the tap started strait. Larger taps all have center holes in the end for this purpose.


Also making a center out of a broken 3/8" tap or using one that has a point on it is a good way to tap a larger hole on a mill. it insures that the tap starts strait.

The number 1 cause of broken taps is not being started strait. This loads one side of the tap heavier than the other side and causes the break to occur. Seldom will you break a tap if it is started strait. I can't imagine tapping threads for a scope mount in somebodies expensive rifle with out some kind of jig to guide the tap.

When I tapped the two holes for the receiver sight on my Springfield. It took 2 full hours of sweating blood on my mill and I broke the $26 6-48 tap 4 times and reground the end successfully each time. Just to tap 2 holes!!!!!

With out the perfectly aligned setup on the mill this NEVER would have been successful, and the sight would be cockeyed in some direction instead of being perfect.

You always have to give yourself every advantage when doing any job so that your work will be acceptable.

More so when working on guns.

Just remember,,,,

"If your work sucks ,,, You suck!"

Sucking on a car part that nobody will ever see is one thing. Sucking on a gun job is down right sacrilegious!

Another installment of my .02. UAYSF Use as you see fit!

Randy

[MBTcustom]

You know Randy, we must have had a very similar manufacturing upbringing. Couldn't have said it better myself, and that's exactly how I use a die. Although, I made a holder that snaps into the tailstock that runs the die straight.

That being said, I always cut muzzle threads to full depth with a single point tool and only after careful alignment of the bore. If somebody screws a can on the barrel and gets a baffle strike, you're going to be hating life. I don't trust a threading doe to cut threads that accurately, and there is too much at stake to cut corners on the most important thread in the whole dam rifle.

[John Taylor]

I always thread the muzzle with the lathe. I picked up a 1/2-28 die a few years back and found out the hole was not strait I can use it to chase threads but if you put it on the barrel in the lathe it wobble a lot. I have never seen one that bad before. If a new die is off at all it will mess up barrel thread quick.

[W.R.Buchanan]

Tim: I submit that threads for cans should have a register in back of the threads and in front as well. That way the registers guide the alignment and all the thread does is take up the slack fore and aft.

Alignment is insured by the registers. Relying on a thread to do this just seems wrong to me.

Most of my midlevel learning was gained by working at Gaiser Tool Co in Ventura CA, we did small better than anyone.

IF you can do small you can do big. It doesn't necessarily work the other way.



I also got production experience from Helderlein Engineering who I did contract work for when I first started by own shop.

I figured out a bunch of stuff myself along the way, simply by not buying the normal way of doing things if it wasn't immediately successful.

Lots of BS on how to do things out there. Look at Obama? he hasn't got a clue, but lots of people listen to him? they need to understand the concept of "the King's New Clothes."

Randy

[nicholst55]

Are you planning to mount a sound suppressor, or merely a muzzle device (brake, flash suppressor, etc)? If a suppressor, do it right - single point, on a lathe. You'll have baffle strikes if you don't, guaranteed.

[Whiterabbit]

if I ever actually thread a barrel in my lifetime, it will be for linear compensators. Not even a brake. I don't like brakes, and CA has blessed us with law that will forever deny us of our ability to own a suppressor (then they complain about the noise at gun ranges.....)

Anyways, I have come to love the civility of shooting through a linear compensator.