Core Seating

[ETG]

I have read all the instructions that came with my set and searched on here looking for how much force to use seating the core in a 22LR jacket. I know it needs to be enough to bump it up to the correct size. I have been using the over-center method and setting the punch so I can see some lead seeping past the punch. This seems like quite a bit of force (both down stroke and up) compared to swaging the cores or point forming. I don't want to damage the dies or the press. Any help is greatly appreciated.

[Toobroke]

What kind of equipment are you using? I've never done the 22 LR-to-jacket process (I have both a BSS 3-die set for 22 cal and C-H/4D 2-die set for 44 cal swaging outfits). You really shouldn't have any lead 'seeping' past the punch--usually means your punch is the wrong size (too small in diameter). You already alluded to it, but when I core seat, I core seat to bullet diameter.

[ETG]

My press and dies are BSS.

[454PB]

My dies are Corbin.

I set the seating die so that it just barely breaks over, and I get just a hint of lead bleeding up around the seating punch. Accurate core weight is required for uniformity. When I was casting the cores instead of cutting them, I had less uniformity. This caused some cores to "overfill" the jacket and the result was more lead extruding past the punch.

Try weighing your cores, they should not vary by more than .1 to .2 grains.

[ETG]

I extrude 3/16" lead wire and swage to weight/size. They are normally within + or- .2. That setting to where the press just breaks over is what I was trying to explain and I can see just a smiggin of lead on the jacket wall - maybe a 32nd inch. If I back off much the bases do not form flat but are rounded around the edge.

[MightyThor]

Some of that rounding is due to your jacket forming. I have dies that form different bullet bases, some more round than others, I have not had any noticeable difference in accuracy between them. I seat the core till it fills the jacket. This is more of a feel thing than I can really describe. best way to put it is I quit when I feel the core stop squishing. I don't think you have to do much more than that because the pointing process reshapes both the jacket and the core locking them together.

[Houndog]

To get this right EVERY time you need a .0001 reading micrometer! When the cored jacket measures the same diameter at the lead line as it does at the base, you've got it right! You can use too much pressure and damage your dies and punches as well as not enough to fill out your jacket! This IS the most critical setup in the whole process. If you are having lead bleed by your punch, it's either too small or you are using too much pressure and actually starting to extrude the jacket. Measuring the cored jackets is the only reliable, and repeatable way I've found to get this step right. I have punches ground in .0002 increments to get the cores just right for Benchrest bullets. For a general purpose bullet, your punches could probably be sized in .0005 steps and be OK.

BTW: if you are squirting core properly, they should vary no more than .1 GR total! I use a water soluble oil at a rate of 6 drops per 250 slugs and tumble them in a pint fruit jar by hand to distribute the lube evenly. I then squirt the cores and boil the finished cores in Dawn dishwashing liquid and water followed by a HOT water rinse, letting them completely dry on a bath towel. You should then let the cores sit at least 3 days before using them so they will slightly oxidize and grip the sides of the cored jacket better.

[ETG]

Thanks - I'll take a mic to them - never thought of that. I was using the lanolin/casteroil lub - put a little on the sides of a plastic container and tumble by hand. the rest is what I do except I never thought about letting them set for 3 days - half of them did but the other half only sat a day.