Jackets stuck on core seating punch.

[Medicaus]

Hey guys, I have a die for a 6mm setup, and the core seater almost always sticks to the pin. I’m constantly have to wipe the pin with some lube off my fingers and I’ve got a lathe, so I’ve used many different pins, when they get too small in D point forming becomes an issue. Just wondering, the inside of the die itself is like a mirror, I’m thinking of running some 800 grit paper in there to make it grab better. Thoughts?

[pertnear]

I'm no expert, but the 800 grit "rough-up" does NOT sound like a good idea. I say contact the original die maker for advice.

[MUSTANG]

I'm no expert, but the 800 grit "rough-up" does NOT sound like a good idea. I say contact the original die maker for advice.

Agree on the comments by pertnear. No to that sand paper in the die.

If I understand you correctly, the jacket is sticking to the punch. I would polish the punch to a mirror finish. In my Corbin dies; the lead "Swells" under pressure as the punch pushes the lead core into the jacket causing the jacket to expand out to the walls of the core seating die. A punch at the bottom then pushes the jacket/core out of the die as the handle is raised after core/jacket is expanded. The lead core punch is NOT a high fit in the jacket, but very close. If your Punch (Pin) is tight on the jacket - that could be a problem area.

[IllinoisCoyoteHunter]

You also might not be seating the cores enough to swell the jacket for a snug fit in the die.

[garandsrus]

The punch is too large a diameter for core seating, probably only by .001 or .002. The diameter you need depends on the jacket you are using and how deeply you are seating the core. I have one set of swage dies that includes 4 or 5 seating punches that vary by .0005 (yes, 1/2 of .001). I start with the smallest and if there is any lead flow around the punch, I go to the next sized punch until the core is flat and the punch doesn’t stick.

The punch for core seating and point forming is a different diameter.

[CWME]

You also might not be seating the cores enough to swell the jacket for a snug fit in the die.

I agree with this. Before modifying anything, I would try a little more pressure. Easy does it.

[IllinoisCoyoteHunter]

You are camming over when seating the cores, right?

[garandsrus]

I agree with this. Before modifying anything, I would try a little more pressure. Easy does it.

The core seating punch should fit inside the jacket until it contacts the core with no pressure. Yes, the case gets expanded as the core seats, but that has nothing to do with the punch sticking in the case. The punch is too big! It really is that simple

As for camming over, some do and some don’t when seating cores. Some people prefer the “feel” of seating without camming. I generally do cam over, but at VERY light pressure. The way to tell when you have enough pressure is that the core expanded to the diameter of the die. More pressure doesn’t help! The problem with cramming over is that it is easy to generate way too much pressure. Something has to give. Normally the punch bends, but the die can crack also. Seating the core can generate the highest pressures of the three steps in swaging.

[IllinoisCoyoteHunter]

Are you using the correct punch? Cores might be too light for the jacket too.

[Medicaus]

Yeah guys it seems to be the only die I have issues with. If the punch is too small it makes the jacket thin around the ogive and you can sing a ring around the bullets. Only 1 in 5-10 to get stuck but its still too many. I can do 1000 with all other calibers no problem. I polished the punch to 2000 grit and it still happens. I even tried a reverse taper on the punch. I'll try going down in 0.0005 maybe it just has to be absolutely perfect with these particular jackets. Dunno. Annoying. I always cam-over for consistency. Cores are a decent weight for the jacket. I might try a punch that tapers (bigger towards the back) to flare it out SLIGHTLY to help improve contact pressure against the die. I know it sounds donkey-backwards but worth a shot.

[IllinoisCoyoteHunter]

Who made the dies and punches?

[RonIa]

When seating a core in a 6mm you should only seat them to make a jacket OD of .243 with very light blow by sounds like you do not have the right size core punch as stated in one comment above they are sticking because there is lead pushing up between your punch and the jacket
Ron

[CWME]

The core seating punch should fit inside the jacket until it contacts the core with no pressure. Yes, the case gets expanded as the core seats, but that has nothing to do with the punch sticking in the case. The punch is too big! It really is that simple

I don't disagree that the punch needs to fit. My experience has been that not enough pressure can also cause the punch to stick if the jacket hasn't blown out to the die's diameter.

[kokomokid]

Maybe the problem is the jackets?

[IllinoisCoyoteHunter]

If the punch was made for rimfire jackets it probably won’t work for commercial jackets. We really need more info.

[garandsrus]

Yeah guys it seems to be the only die I have issues with. If the punch is too small it makes the jacket thin around the ogive and you can sing a ring around the bullets. Only 1 in 5-10 to get stuck but its still too many. I can do 1000 with all other calibers no problem. I polished the punch to 2000 grit and it still happens. I even tried a reverse taper on the punch. I'll try going down in 0.0005 maybe it just has to be absolutely perfect with these particular jackets. Dunno. Annoying. I always cam-over for consistency. Cores are a decent weight for the jacket. I might try a punch that tapers (bigger towards the back) to flare it out SLIGHTLY to help improve contact pressure against the die. I know it sounds donkey-backwards but worth a shot.

A punch that is too big will cause the brass to thin as the punch shaves the brass. Most jackets are tapered so the deeper the punch goes in to fully seat the core, the smaller it needs to be. The only possible problem with a punch too small is that the lead flows around the punch instead of expanding the case. This could cause the core to stick on the punch if there is a burr on the punch. After seating, the core should be flat across the top.

Putting a taper on the punch could cause the jacket to not fit in the point form die. Tolerances are pretty close and the point form die is more than likely less than .001 larger than the core seating die.

[jimrk]

More details on what you are using, what are you meaning by "core seater almost always sticks to the pin"? Is the core seated in the jacket and when ejected from the die is it 'stuck' to the core seating punch"? Have seen that when the punch is too small for the jacket and lead flows past the punch so above the seated core there is a layer of lead between the jacket and punch.

[Liseo]

Too much lube?