Lee type blank sizing dies now available

KeithB

Resident Half Fast Machinist
#1
Now offering Lee typer sizing dies for those of you that prefer that type of push through sizing. These dies are made from 1144 ("stressproof") steel on CNC equipment, The body is threaded 7/8-14 to fit standard presses. The die has a 3/16" pilot hole drilled half way through from the bottom end and a 1/4" pilot hole on the other end.

Price is $9.00 each + $5.00 shipping for 1-8 pieces, free shipping for 9 or more.

If you're interested start a conversation here or email me at keith@bigfoottech.tech

LeeDie3.jpg
 

JWFilips

Well-Known Member
#8
Wow These are something I would love if I had the equipment to open them up properly!
For you guys that are buying them ( obviously with Lathes) could you please describe how you open one up to a custom size diameter?
I have do a dozen of Lee's , of course bought close to the size I need and do the old emery paper on a steel rod rolling around thing!
Works ok but I have over shot a few.
Would love to know the proper way with machining
Thanks
Jim
 

Brad

Administrator
Staff member
#9
I chuck them in the lathe and find a drill bit undersized by maybe 30 thou for the desired size. That removes the majority of the material but drilling doesn’t leave a round hole.
I then use a small boring bar and check size with pin gauges often. Once I am around .002-.003 under what I want I cut the taper at the opening and then polish to final size. The polish, clean, check sequence is repeated over and over until done. This is the time consuming part.

Oops, forgot to add that I first back drill the exit end at least .010 oversized. I do that 2” deep so I have roughly 1” for feed in and sizing. The actual sizing section need not be much longer than 1/2” long.
 
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Brad

Administrator
Staff member
#11
Here are a couple examples.
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This one was home ground. It has a nice sharp edge and leaves a good finish.

99CA78C3-1660-4E4C-A2F1-5C67E0726CA3.jpeg
This is a commercial bar with a carbide shank and uses inserts. It doesn’t leave as nice of a finish largely due to a very sharp radius on the cutting edge.

Advantage of the carbide bar is that it flexes far less when stuck out a long way. Disadvantage is the rougher finish it leaves.
Tool flex with boring bars is a real issue. My little home ground tool flexes a ton when cutting up to an inch. Needs to be long and skinny to make a 30 cal sizer but long and skinny means more flex.
When I bore a hole with the home ground tool I make many small cuts, maybe .002 per side at a time. When I get close I also make multiple spring passes, a cut where the tool is not moved. This means the tool removes metal left on a previous pass because the tool or workpiece flexed away from the cut. That has bit me in the ass in the pass when I ignored it. I want to cut another .002 deep but don’t take a spring pass first. That means when I take a spring pass after the tool change and initial cut I may be .004 deeper! Messed up a sizer that way the other day when a .433 sizer suddenly measured .433 and I still needed to polish it.

Polishing is done under power with a split rod, emery, and lots of oil. I start with 240 grit to remove material quick and finish with 400 for a better finish. I polish, pleas the die, hen check with a pin gauge. If I want a .433 sizer I want a .432 pin to enter easily but a .433 pin to not go in. That means I am usually .0003 under desired size. That small difference is far less that the variances in final size due to alloy changes.
 

Brad

Administrator
Staff member
#12
I have my GoPro charging now Jim. If time allows tonight I will make a few videos to show the process I use.

Keith did the easy part when he made these blanks. He did the simple material removal and threading. The time consuming part is the finishing and final polish. Keith can make a blank in what, 5-8 minutes total? I bet it would take him more like 30 minutes to do the remaining work. Depending on how it is going I can spend up to an hour doing that work.
 

JWFilips

Well-Known Member
#13
Brad,
Thanks for explaining!
That is similar to 18th C Gunsmiths making reamers to open up rifle bores! The drill comes first then hand forged reamers are used to come close to caliber size then on to the rifling cutter! Every barrel was an individual! It was slugged then a cherry cut to match and then a mould was made ....that mould followed that rifle!
 

JWFilips

Well-Known Member
#16
Brad,
Yes I know I loose track of time making tools or making Flintlock rifles! That is why I gave the later up unless it is for me
 

Brad

Administrator
Staff member
#17
You quickly learn that if you charge a set rate per hour the work becomes impossibly expensive.
This is why I don’t make things for $. This keeps it a hobby and in a hobby my time has no value!
 

KeithB

Resident Half Fast Machinist
#18
See, it’s a win-win for everybody.

To make one die takes about 7.5 minutes machine time, costs $2 for material, takes two simple setups, and has to be handled several times. I have to account for all the time and costs. It’s still fun for me but it sure isn’t a hobby anymore!
 

Ian

Well-Known Member
#19
Not counting tooling costs, electricity, coolant, paying your apprentice.....and a zillion other things. I'm just happy you can make these on slow days and price them so reasonably while still making a few bucks.