Finishing a Lee style sizer

Ian

Well-Known Member
#21
You can always turn and polish the exact size of pin gauge you need first, then use it to gauge the sizer bore. Make it with a .002" or .005"-under first step so you know when you're close.

Being cheap, I use ball gauges and stop about .002" short of the actual bullet size I want, then check ut by sizing an actual bullet, then polish more if necessary.
 

Brad

Administrator
Staff member
#22
I always use an actual bullet as a final check. I have gotten to a point where I can get awful close before that check.
 

Brad

Administrator
Staff member
#29
I like about 1/2” of actual sizing section. More than that increases the force required and also makes it harder for following bullets to move the ones in the siIng section when using short bullets.
I use a 2-3° taper on the entrance. It lets bullets enter easily even if over sized. It is also shallow enough to help bullets center up before actual sizing. I also like he gentler transition from taper to sizing. By the time I polish to final size the transition is well smoothed out.

Neither of these are written in stone but they are what I have found works for me.
 

popper

Active Member
#30
Years ago I had a project needing some plastic extrusions. Met with a local guy and got to talking die. They use a pressure extruder, just heating the plastic (ABS) to soft. Used a very short sizing portion with large entrance. IMHO Lee uses a wire extruding shape with 1/4" size section, big entrance with high taper. NOE uses a straight 3/4" size and radii entrance. I'd sure do it different. Too many stuck slick sided rifle bullets i them. Cu wire (pulled) extrude die appear to have large entrance, slight taper then short size section, radii exit. Your approach appears more like a good rifle throat/bore. Only problem I see is we don't use that much pressure, soft alloy will swage to the taper before getting sized. Adds more friction but should, if concentric, make good bullets. Point I'm trying to make that I learned from the plastic guy is the stress and heat generated in sizing causes warping on the exit side. My thinking is the counter bore section needs to be 0.001 over size to prevent bananas. IMHO multical length bullets need a different shape than 'square' ones and I haven't seen any commercial specifically for rifle.
 
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