View Full Version : Ejector pin diameter

04-18-2006, 08:07 PM
OK I inlarged a Lyman sizer die to size a bullet .461 , from a .458 sizer this evening .

Will the old ejector pin work without making a mess , from lost lube ?
Or do I make a new one ?

I am just starting to use a freinds lathe , mill and surface grinder and other shop equipment .
So I am sure a new pin is a good learning project , but if the existing one will work for now .
I would rather lube and size then shoot , rather than spending more time inside .


04-18-2006, 11:41 PM
I'm guessing it'll work OK. I've got a .360 that used to be a .358 that I use regularly with no problem. If it was me, I'd give it a go and see. Regards, Woody

04-19-2006, 12:37 AM
I think it'll work. Have you measured the pin to see where it's at now?

04-19-2006, 03:24 AM
...........Usually .0015" under die ID is fine. There are exceptions like lube consistancy, if you're using heat, and how much arm you're putting on the lube piston. If the ejector pin is from a .458" die it may be .4565 (or so) to .457" on the high side. Maybe .003" total clearance, which will probably be a td much. Try it and see before making a new one.


04-19-2006, 07:30 PM
I just tryed it .
No luck , I have some lube coming out around the pin .

So I will head over and see how many trys it takes me to make a new pin .
I want to learn , so this is a good project

Thanks for the input .


04-19-2006, 11:09 PM

Actually, making up a properly-fitting ejector pin is one of the best ways to get an education in precision machining-to-size I know of. You can use any good free-machining low-carbon steel, like 1018 or 1030 - don't start with drill rod, as it is a bit sticky. It'll teach you a lot about feeds and cuts in a hurry. And remember, after you've cut it to length, to cut on the cross-feed to make the upper end a very slight cone, one or two degrees on the compound feed, so the edges of the pin fit the edges of the bullet base solidly, and there is a bit of space for any sprue irregularities. You may spoil one or two, but they can be later re-cut for another, smaller die, and you'll learn more about machine work in a half-hour than any other job I know of. GO FOR IT!


04-19-2006, 11:15 PM
When I make my own sizer dies, I build the punch (ejector pin) early and turn it to .001" less than I want the finished die to be. I then use it as a gauge to hone the die to final size. Once it's a snug oiled fit, the sizer portion is usually ready for a "boolit" test for size.

04-20-2006, 03:14 AM
..........I use W-1 for the dies and pins. As with any other machining, if both ends aren't supported, don't allow any more to stick out of the chuck or collet then is absolutely necessary. I like to use HSS for my finish cut, but will use carbide to get it down to about .015" of finish size. Besides, this saves the honed edge on the tool.

For finishing I like a bit with about a .020" radius on the nose, and run cutting oil on the last 2 cuts. I'll take a .010" cut, mike the part and dial in to finish the piece. As Floodgate said about a dished face, you can grind a tool which you can bring up to the end of the workpiece and advance it a few thousandths to form the concave surface and then feed it out to cut wider till it's about 1/16 to 3/32 from the edge, depending on the pins' diameter.


04-20-2006, 10:18 PM
Well after spending 2 hrs messing around ( 5 rejects for several reasons ) I was given the OK from my freind that the 6th met his specs .
A 60 something retired tool maker , he is a stickler for doing things HIS way and right .

Not sure what I used for steel .
He just said , use this ..... as he handed me several pieces .

I will need a LOT more practice and learning .

Buckshot and the rest of you , thanks for the tips .
I will be learning .
I will be inlarging several more sizers , so I will make use of my rejects .