A story about installing a rifled barrel into a shortened Handi shot gun barrel

[corbinace]

I posted a question a bit back asking about the process and this is what is happening with my project. This is intended to be a photo-journal of how it goes, and will be a work in progress for some time to come likely.

I had originally intended to borrow the lathe of either a friend or my son-in-law. Neither of those avenues seemed to be working.
So I bought a 1965 Rockwell-Delta 11x36 lathe at auction. The lathe was filthy with caked on oil residue and years of grime, but once cleaned up it looks pretty presentable.

The lathe did not come with any tools or tool holders and only a lantern post holder. Instead of buying tool holders for the lantern style holder I purchased an AXA Quick change tool post that fit my machine. The QCTP had a base pad that needed to be machined for the t-slot of the compound slide and I had my SIL mill it out for me, as I watched and learned.

I turned a dead-center shouldered 60 degree dead center for the headstock.
The lathe came with a very nice Rohn? live center for the tailstock.

I did not have a lathe dog for turning the barrel between centers but did have a chunk of scrap brass with a 1-3/8" hole in the center that seemed to be a good candidate for my barrel blank. A bit of drilling and tapping and so far it seems to be working fine.



I have only been able to get the barrel reduced in diameter from 1.250" to 1.060. I had to do a bit of messing around with adjusting the tailstock to get it turning straight. Originally it was .027" smaller on the breach end of the 18.5" cut. Possibly ok for this project, but I wanted it closer. I have it down to an error of .002" smaller on muzzle end and called it good enough there.



I am trying to make small enough cuts that I do not need to use the steady rest in the middle because it really diminishes the length of travel. I will monitor the diameter in the center to make sure it is not getting bigger, hence bowing away from the cutter.
I am also stopping cutting when I can feel any heat in the barrel to alleviate the barrel getting longer/tight between centers and bowing out. I really do not know what is the proper heat threshold to stop at, so when my cold hands feel a bit of warmth I stop. It seems to work out well, because by the time the barrel gets warm, my toes are frozen from standing on the unheated hangar concrete floor. Everyone is ready for a break.

I will edit this post with pictures inserted later. For some reason I cannot get them off of my phone.

[challenger_i]

Get some "Hot Hands" from Wally World and place in your shoes, under your arches. Works wonders!
Hunt down a Cool Mist spray lubrication system and run water soluble oil cut with distilled water. Use an inexpensive
air regulator to adjust the mist on the work piece. These will help out with the "heating and cooling" issues.

[Jedman]

Everything sounds good ! You will learn a lot and your barrel will work out fine. It’s a worthwhile project and will probably not be your last.
Jedman

[uscra112]

Those Delta lathes weren't bad. I saw a few in my career as a machine tool rebuilder. Good find.

Some important watch-out-for points in Post #5 of this thread:

https://www.practicalmachinist.com/f...-lathe.149432/

[JSnover]

Get some "Hot Hands" from Wally World and place in your shoes, under your arches. Works wonders!
Hunt down a Cool Mist spray lubrication system and run water soluble oil cut with distilled water. Use an inexpensive
air regulator to adjust the mist on the work piece. These will help out with the "heating and cooling" issues.

I'll second that. Didn't care much for the Cool Mist fluid but the unit itself works just fine with the right mix.

[country gent]

Heres one a little less messy than the cool mister. I use a simple dripper with black cutting oil.
My drippere was made from a oiler it has an adjustable drip to oil bearing. lathes and other machines had these on them for bearings mine holds around 4 ounces of oil.

Put the oiler in a pipe mount with a small tube about 4-6" long out of it you want this tube at an down angle for flow. It can be sleeved right into the bottom of the oiler you need a stem to mount it on your magnetic base.

In use set the small tube so the drip hits right at the cut on the point of the tool a small drop every 15-20 seconds. Watch you will see when the oil on the cut runs out and the next drop should be a little before or right at this point. The other plus over the cool mist is you can run oils water solubles and most other fluids thru this.

I have 2 misters both home made that I run oil in one on the mill and one on the saw. The air borne mist can be hard on sinuses and breathing.

For a fixed stand a flex coolant line on a magnetic base is very good and is easy to adjust.

A small soup can ( single serving size) with a smnall valve will make the dripper also.

Ill get out in the shop and get a pic of mine shortly.

[country gent]

Heres the dripper its setting on the drill press. But its handy and puts the oils right where needed with out a lot of air borne fumes. The oiler drips into the copper tubing its blocked of at the tune so it runs down to right where its needed

[uscra112]

Like that. I've done it manually with an oilcan, but holding the can through a long cut would be mighty tedious.

[country gent]

It just sits there on the carriage following along on a long cut you prop your feet on the carriage and take a nap until your feet fall off.

[uscra112]

Now I'm imagining a wick at the delivery end. Dragging in the cut just ahead of the tool. Continuous delivery rather than drops.

[country gent]

We had 3 delta lathes in the shop in high school they were good machines not as rigid as some but were solid machines.
Turning the center on a piece of round stock is an accepted shop practice. Once turned its dead true and remains so until removed I have several in my box hanging on to them saves a lot of cutting next use. For a make shift dog when you want to turn full length tac weld a small rod on the end of the part. You can turn end to end.

Lighter passes with a heavy feed will put more heat into the chip than in the part. .005-.010 with a .030 per revolution feed will leave a spiral but the chips should break and heat will be more in the chips. but it will take a finish pass to clean up.

[corbinace]

Lighter passes with a heavy feed will put more heat into the chip than in the part. .005-.010 with a .030 per revolution feed will leave a spiral but the chips should break and heat will be more in the chips. but it will take a finish pass to clean up.

I will try that this morning. I was cutting .005" deep and using the slowest feed possible at 509RPM. I think it was 224 revs/threads per inch????
I learned last night that I should be cutting faster at about 700 RPM as well.

I am currently using a regular carbide insert on this 416SS while I wait for my SS carbide inserts to arrive on Wednesday. I do have a couple of new high speed bits but have not ventured into sharpening them yet.

Basically lots of fumbling around and experimenting while I have lots of material to remove. Hopefully, by the time I get to the final diameter, I may have a tiny clue as to what I am supposed to be doing.

Even though I am fumbling, I am having fun, and that was the general plan all along.

[Hannibal]

Following along with interest to see how this plays out.

[corbinace]

Following along with interest to see how this plays out.

Me too

[xtriggerman]

I'v turn more than a few bull blanks to taper and I never use fluid to cool. When the barrel starts to get hot, all you need to do is loosen the live center on the tail stock and re snug, Any expansion is fixed. I'm not in any hurry so once the heat is bad and the chips getting to gold blue, just stop. Experience will teach you about the relevance of feeds and speeds. The big thing is tool sharpness and all ways be sure your tool cutting tip is just slightly below the tip of your center point. I use carbides on and off but once you learn how to put good cutting angles on a HS tool, and in doing so, pull long, long spring like chips off that dont turn color, you know your there with your technique in tool grinding. I learned in GS school then had an old Craftsman until 1990 when I bought a 13x40 Grizzly. I would buy another grizzly and probably will one of these days since my Giz has about .0013 of head stock slop. Sounds like your on your way to a very satisfying hobby. I'd be lost without my gun tools. Enjoy!

[country gent]

HSS is hard to sharpen just remember you need relief to make the cutting edge. Its hard to describe well but several on you tube have very good how tos on it Abom 69, Tubal cain, this old tony, and some others.

Basically you want 7*-10* back relief on front and side. then a top relief of 10* down and away from side angle. Sharpen/grind on a pedestal grinder then hone to a sharp edge. You will need a water pot at the grinder to cool tool as you form it.

I dont know if they are still in special projects I posted pics of some tangential tool holders I made these are very good and only require sharpening the face of the blank. I prefer HSS on long cuts, the cutting pressures are lower than carbide and chatter seems easier to control.

[country gent]

Heres the tangential tool holder

[Shawlerbrook]

Consider getting some of the cushioned work pad for standing on concrete.

[challenger_i]

If you have a Tractor Supply handy, they have horse stall pads that work excellent for floor pads. And they are very tough!

[corbinace]

I got a bit more done today. It was warmer and I had other work to do at the hangar, so there were many opportunities for the work to cool down.

I increased the rpm to 700 and the feed to 128?? TPI while maintaining the .010” cuts for the major diameter reduction. Going back to 224 tpi and .005” for the final cut of a dimension. .015” caused a noticeable decrease in rpm and seamed to make the chips get gold, so I only tried that once.

Here is my set up;


I was able to get the first diameter for the rim done, as well as the major chamber portion;


The finish is pretty smooth by taking a very small final pass at a slow feed speed;



You can see I left the rim diameter long so that I can part it off in that area. You may also be able to see some smaller diameter area closest the the brass dog junction. That was the scene of a crash. A pretty bad one, breaking the carbide insert, ruining the dead center surface and generally making a mess of everything. Luckily it only took an hour to get back up and running and no critical parts/pieces were completely ruined.

Tomorrow I hope to get back up there and get the major barrel dimension done.

Next, I am going to up the ante. I am going to thread the barrel for a suppressor. Luckily I have some extra length to play with in case I need to have a second go at it. The barrel started out at 19 inches and I think I will use less than one inch on the dog and parting headstock end. I hope to be able to get some part of the remaining two inches threaded.