making sizing dies--tapering mouth???

[kevmc]

Making some RCBS style lube dies....

Thoughts on how you taper the top/mouth of the die and how much?

I'm using a small lathe, but only know enough to be dangerous!!

[theperfessor]

It shouldn't take too much, how about using some abrasive paper on a smaller-than-die diameter dowel rod. Just polish the mouth of the die at a slight angle to enlarge the diameter at the mouth by about .005" - .006". Probably other ways to do this but this method works quickly enough to get the job done but slowly enough for you to stay in control and not take off too much material.

[Tazza]

You state that you want to make them from scratch? You can cut a taper with a boring bar and set your cross slide to the desired angle.

You will also need to harden the die and polish the machining marks out.

[454PB]

I do it as theperfessor described. I'm sure there are better ways with better equipment, but it's simple and I have the "tools" on hand.

[Steven Dzupin]

Depending on the hole size a tapered pin reamer works very well.

Regards,

Steve

[jmorris]

I use a tapered reamer.

[kevmc]

Does everyone harden their dies ??
Method ??

[jmorris]

I didn't.

[454PB]

I don't harden either.....and I have sizing dies that have sized many thousands of boolits.

[dragonrider]

I make my dies for my Star, hardening them is just a waste of effort. A well sized and well polished die won't wear out in my lifetime.

[Fritz D]

I didn't.

Ditto. I've made a few dies using mild steel, I did not harden them. I size mostly linotype boolits and they seem to work fine.

[ipijohn]

I taper mine with a small grinding wheel in a dremel tool while they are rotating in my lathe, then polish with 1000 grit wet/dry on a stick.

[BattleRife]

If you make them out of a 4140 normalized and tempered or HTSR bar they will have a hardness of HRC 26-30, which will be more than enough to last forever.

[kevmc]

Made my first today!!
Used die banks from theperfesser, made life easy!
Just need to figure how much to bore on the lathe, allowing room (but not too much) to finish and polish.
Today I was aiming for .4115, ended up at .4118...works well tho....
If I don't like it, I'll open it for 44's......

[fast ronnie]

An easy way to cut a radius on the inlet side it to set your compound on say a 7 or 8 degree taper, then go to 15 or so, working up till you have a somewhat formed surface, then blend in with a dowel rod or round bar stock and coarse emery tape. After getting the shape, then use progressively finer grit to polish. I do intake ports and radiused fittings this way on racing engines.

[kevmc]

An easy way to cut a radius on the inlet side it to set your compound on say a 7 or 8 degree taper, then go to 15 or so, working up till you have a somewhat formed surface, then blend in with a dowel rod or round bar stock and coarse emery tape. After getting the shape, then use progressively finer grit to polish. I do intake ports and radiused fittings this way on racing engines.

Good idea!
I did something similar, set compound at 10* and then blended & polished......worked petty well.