Bullet Mold End Squaring FIxture

[theperfessor]

I was having trouble getting the ends of my bullet molds square. I don't have any problem with parallelism and perpendicularity for the four principal faces (inside, outside, top and bottom). My 4" vise and a good set of parallels takes care of that adequately. But since my molds are 3.0" (4 cavity) and 3.6" (5 cavity) long trying to hold them in a conventional milling vise is a frustrating exercise. So I decided to make an end squaring fixture.

I bought a precision ground (well, it is now) 3" x 3" angle plate from Enco for about $12. The two main surfaces were very square, but the edges were off. I laid the plate on one side on my mill table and shimmed around on it until the two main surfaces were perpendicular, then I milled it off enough to clean it up.

Then I flipped it over and Milled the other edges parallel.

I drilled and tapped three 1/4-20 holes is one edge and bolted on a piece of tool steel. Then I drilled and tapped one of the faces so that I could bolt on a 3/4" piece of plate with a notch in it. The notch has an aluminum insert in it so that the clamp screw (3/8-16) wouldn't mar a mold surface. The two slotted clamps are made from some aluminum scrap, again to not mar the mold surface, and are screwed into the plate.

The fixture is real easy to use. Just drop the block in, lightly clamp using the 3/8 screw, tighten up the the slotted clamps, then snug up the 3/8 screw. It only takes a couple minutes to get a good square end. I just got done running a batch of twenty mold halves, enough to make ten molds. I checked all twenty molds, and there the end surfaces all came out parallel within 0.0002". And by working directly off the mill table top I was able to hold the block-to-block length variation to within 0.0015", which is more than good enough IMHO.

Don't know if this will spark any ideas, several people have mentioned having this problem.

[45nut]

looks like a right handy tool!

[scrapcan]

10 sets of blocks, already to go. Now what will you due with them! Hmm, I bet you get to put some holes in them next.

What are you going to try first Perfessor?

[theperfessor]

45Nut -

Yes it is. One of the well respected forum members pmed me about this pointing out another method - using the edge of an endmill to square the blocks off while still in the mill vise. This is a fine method that works well, I use it a lot. But I wanted a fixture for a good reason.

I have no power feed on my Y-axis so I have to use manual (hand feed) to do it that way. And I have to change from my carbide face mill to an end mill. This way I can use the power feed on my X-axis and while its cutting I can deburr the last set of blocks at the same time. It takes about two minutes to cut the ends and the same amount of time to deburr the last piece, why not save a little labor and do both steps concurrently?

I figure the time I spent making the fixture will pay off eventually, I look at it as an investment in the future and not a waste of time in the present.

[theperfessor]

Manlyjt -

Well, I still have to put in the alignment pin holes and press in the pins before they are ready for cavity boring. Right now I'm prepping to do some shrinkage testing, see this thread:

http://www.castboolits.gunloads.com/showthread.php?t=88160

Once I know how big a hole to put in them I'll probably make a five holer for my 45-70 Marlin, right now it's the only gun I have that I don't have a suitable mold for. I'm also interested in making a full WC mold in .41 size for my M57. And I'm thinking of making some combo molds, such as a mold with three cavities of one type and two of another, such as a .44 mold with two 250 gr SWC cavities and three 200 gr full WC cavities.

Unlike a lot of the talented and hardworking folks here that make a living making and modifying bullet molds, my main income is from teaching, so I have the luxury of being able to experiment and develop my ideas as I see fit. And if I think anything I do is of interest and benefit to the members here I will share the results freely.

[scrapcan]

Perfessor,

Yep I am watching the other thread also. I think there is a chart in the NRA cast bullet handbook that talks about shrinkage, but it has been a while since I looked.

I watch all of your projects with interest. Our local community college saw fit to turn the welding and machine tool labs into a room full of excercise bikes. And a nice indoor shooting range into an aerobics room. I say let them ride bikes and run outside where it will do some good. But I was obviously in the minority.

[theperfessor]

Isn't it amazing in a sick sort of way how we deny our fellow citizens the tools and activities that made us a great country? I'm of course referring to teaching kids some basic technical skills and encouraging organized, safe, competitive shooting in our schools.

I could go on but that's for another area of the forum.

[deltaenterprizes]

Isn't it amazing in a sick sort of way how we deny our fellow citizens the tools and activities that made us a great country? I'm of course referring to teaching kids some basic technical skills and encouraging organized, safe, competitive shooting in our schools.

I could go on but that's for another area of the forum.

Sad state of affairs!

[scrapcan]

I hear you. I might have a chance to take a college machine tool course, but it is 45 miles one way from the house. Pretty sad state of affairs if you ask me.

[Frank46]

I had a boss that absolutely refused my taking the basic, intermedtiate and advanced machinist courses offered by our company. At the time the only lathe I had
was a craftsman 6" with a 20" bed. Frank

[frankenfab]

I was disappointed that Tool & Die (8 hours a day) was no longer offered at the college I attended due to lack of demand. I had to settle for a 1 year machine shop certificate and an AAS in Manufacturing Technology. I really wanted the Tool & Die training for the fine accuracy/fitting and more study of heat treating.

There's just not as much of a demand for hard dies due to new manufactuing technology.

[Just Duke]

Isn't it amazing in a sick sort of way how we deny our fellow citizens the tools and activities that made us a great country? I'm of course referring to teaching kids some basic technical skills and encouraging organized, safe, competitive shooting in our schools.

I could go on but that's for another area of the forum.

Grab what you can while you can still get it.
I'm having to learn to make just about everything I might need to last me what's left of my life. Of couse most here are too.

[Doc Highwall]

Even if you are a short timer for working I think we should look at something that we can use when we retire to help keep our minds sharp and use in our hobbies. I just hope my body is willing when the time comes.

[theperfessor]

Doc, I agree 100%. My wife retired a year and a half ago and now does free tutoring at a local literacy center; this fall she is planning on teaching some basic freshman college classes on a part-time basis. I've known too many people who retired and then had nothing to do besides wither and die. The happiest retirees I know are now busier than they were when they were working.

You not only have to plan for your financial needs you also have to plan for your intellectual and emotional needs. With all the cutbacks in funding to schools there is a desperate need for tutors and classroom assistants to help the overworked folks who are facing larger classes with less help.

I don't know of any school that wouldn't welcome volunteers for a lot of things. It's a win-win situation for the kids and the volunteers too.

There's also a lot of schools that offer low cost non-credit courses that retired folks can take. Our University has a lot of them, and you can audit regular classes that don't fill up for (I think) $5. You don't get to take tests and you don't get a grade but otherwise you get to participate fully.

I don't know a single professor that doesn't welcome mature students in their classes. It's another win-win for all involved.

[KCSO]

Check out the MIT on line machining video's, there free and very good for beginners.