Removing a bevel base

[Brad]

My Lee 120 TC mould for 9 mm casts .001 smaller than I want and also has a bevel base, a feature I'm not a fan of. I finally got up the nerve to throw it in the lathe and fix these issues.

Have to get it in the 4 jaw chuck and indicate each cavity as you go. Doesn't take long after you get a feel for the process. Getting that feel took me quite a while.

Getting ready to make a cut. The tool was the first step in the whole process. It was ground for a 5/16 inch square bit of HSS. That is an art I am learning, tool grinding properly is truly an art.

Two down, 4 to go.

The final results. The mould is heating, along with the pot right now. Will bve interesting to see how they come out. The burr thrown up by the cutter was removed with a bit of 400 grit paper and followed with a little steel wool.

I have high hopes for this mould now.

 

[KHornet]

Looks good so far! Looks complicated!

 

[Ben]

Now you're talking Brad ! !

I'm anxious to see and hear details of the results of your work.

Ben

 

[smokeywolf]

Good stuff Brad.

An example of a 3/8 x 5/8 internal single-pointing tool.

During the first 2 years of my apprenticeship I spent a lot of time sharpening drills and grinding form-tools free-hand on a pedestal grinder. This one I think I did about 25 years ago and can tell that I only roughed it free-hand, then finished it on a surface grinder. Judging by the size and relief angle, this is for 1.5 inch I.D. and up.

 

[Pistolero]

That is a really nice looking tool. Single pointing internal threads is still on my list
of things to learn.

Brad,
really nice work. I have been telling myself that I need to do this, too, but mine
work fine as is and too many other things have to be done. Like replacing rotted
fascia boards and rehanging the gutters on the second story and replacing the
head on the JD 425 when the new (used) one comes in, and keeping up with mowing
about 7 acres, and adding the alternator to the Super Surfer mower deck, and
well you know, lots of stuff.

Bill

 

[Grump]

Wow, you be really ambitious with that!!! Hats off for taking the time to do it right.

My dad reports playing with BB vs. PB booits of otherwise identical configuration in the .38 Special and his loads, his revolver and himself all together never could find a conclusive difference. Moulds were in the rec room or whatever at Camp Pendleton decades ago. His 50-yard groups were tight enough for the 10-ring but not tight enough for more than half in the X-ring, and no consistent differences in grouping. Still, he settled on ordering PB moulds for himself later on.

 

[Kevin Stenberg]

Showing my ignorance.
Does a BB bullet have that slight decrease in dia. at the base.

 

[Rick]

Notice the bevel at the base of the bullet. This is a bevel base, originally developed for easier seating in the case.

 

[KHornet]

BB bullets are easy to load, but never found them as accurate as sharp, clean flat bases.

 

[williamwaco]

I did that a few years ago with the Lee 358-158-SWC.

There was absolutely no difference in accuracy.

After 80 5 shot groups. 40 groups with each bullet
the results were

Flat Base average 1.37"
Bevel Base average 1.38"

You can see the raw data here if you like.

http://reloadingtips.com/pages/exp_bb-vs-pb-accuracy.htm

 

[James W. Miner]

I did it with the same boolit and did get an improvement in a .357 at 50 yards.

 

[smokeywolf]

Just going through the shop and found a boring head packed away in a box with other goodies. For those who are not familiar with a boring head; they are mounted in the spindle nose of a mill, have a boring bar inserted in one of several holes. The part that holds the boring bars is positionable by means of a dovetail and a screw. This allows boring different dia. holes in a part clamped to the mill table or in the vise.

My question is does anybody else here have a mill and have you ever moded a mould cavity by putting it in the mill vise, indicating it in, then, with boring head and bar, taking out a bevel base or gas check shank or perhaps with an end mill instead of boring head, change nose configuration or plunge on through for a hollow-point pin?

 

[James W. Miner]

Buying a boring head is still on my list. I have the bars but always seem to be out of money.
I made my own mold vise from cast iron risers and it fits in place of my mill table so I can use the gibs.
I make my own cherries from oil hardening rod and make cutting edges on my Vertex, finish by hand with files. I made many molds from scrap aircraft aluminum.
I just have the Smithy, Granite 1324. Lathe, mill, drill.
One $5 length of drill rod will make 20 cherries. I use 1/4" scrap stainless for sprue plates.
Cost is just my time. What I have learned about molds is priceless, how to get almost perfectly round boolits, only what is needed to vent blocks and best of all, my designs are never drawn on paper but my revolvers have all shot 1/2" groups at 100 yards. Mostly blind luck but it has taught me the best designs for accuracy.
I have never had a second of machining experience, learned on my own when I got all the equipment cheap from a fellow that had a stroke.

 

[Brad]

Jim, learning by doing is exactly what I am doing. Thinking things thru helps a bunch. Sure helps when you do things in the right order.

A mill is on my list. It would let me do lots of stuff that I want to try. I even have a separate 220V panel in the garage with 60 amp service just so I can run wire easily to the mill.

 

[James W. Miner]

You can do it.
I have my 700# gun safe and the lathe in my basement. I got them down with no strain or danger. They will NEVER go back up! Maybe hire Bigfoot or aliens! The Smithy is only 120 volts. The motor quit on me a few times and I found the brush springs got too hot. I ordered new ones but found springs in my collection of junk. It has not quit again.
If you buy a Granite I am sure it will quit in the middle of a job. But you now know why.