Core seating different jackets

[B R Shooter]

Made bullets using J4 jackets and they shot very well. Bought some Bart (hines) jackets, used the same cores and seating pressure, don't shoot for beans, not match grade as the others. Anyone see the same thing?

[Valornor]

I have seen that different brands of jackets seem to require different seating pressures. I believe it's due to the geometry on the inside of the jacket, I might try backing off on seating pressure and see if that helps. At least that's been my experience. Your results may vary.

[TonyL]

It could be the diameter of the core seat punch needs to change. Look to see the difference in lead bleed by. For example I use a 0.2105 punch when making 6mm 68 grain bullets with J4 0.825 jackets and use a 0.2145 when making the same bullet with Sierra .825 jackets.

[B R Shooter]

Tony, sent you a PM.

[Utah Shooter]

It could be the diameter of the core seat punch needs to change. Look to see the difference in lead bleed by. For example I use a 0.2105 punch when making 6mm 68 grain bullets with J4 0.825 jackets and use a 0.2145 when making the same bullet with Sierra .825 jackets.
Yup. If you can get 5-6 different punches in .0005 increments you can make sure you have the proper one for the jacket.

[GerryM]

The Hines jackets also Barts and sta moly are pretty close too straight walled jackets once you get the proper punch
usually your set and can change core weight with little problem. The j4 and Sierra jacket have a taper
when changing weight of the core usually you need a different punch for core seating.
If the punch your using in a bit too large you will have problems with seating and sometimes the jacket will stick to the punch and not release.
If the punch is too small you will get bleed back on the sides of the jacket and the result will be bullets out of balance.
I hope this helps to explain your problem

[onomrbil]

As far as quality, I have won matches using both 30 & 22 cal Hines jackets for my bullets. Better than J4s? I cannot say because I win with bullets made with them too. I have no problem switching between the two, just get your core weights correct and get them in there properly. You should know when that happens. The punch question depends on how far down the jacket the core is going to be. I needed a smaller diameter punch for the Hines jackets when making lighter 22 cal stuff; they are tapered a bit. . .

[midnight]

I've found the only solution to having the proper core seat punch is to get a lathe and make your own. Almost every jacket/bullet weight combination requires it's own punch so I turned a whole bunch of blank punches & turn them down as I need them.

Bob

[B R Shooter]

Bob, you are right. And I have done this exact thing. At least for the Blackmon dies, punches are pretty straight forward. I use either W-1or O-1 1/2" rod, and you only need to turn down a couple steps in the rod. I turn to a couple thousands over diameter for the "working" end, then polish it down to size with 600 paper. Especially what Tony above said, such a different between J4 and Sierra.

[midnight]

I use O-1 drill rod too. For "S", "H", & Walnut Hill punches there are only two diameters on the head end & tolerances aren't critical. I turn the punch end down to about 0.450 and make a dozen or more of each at a time. I don't heat treat the whole thing but I do case harden the business end with "Cherry Red" after polishing to final dimension.

Bob

[B R Shooter]

A .2125" punch works perfectly in Barts jackets, .820" for a 68 grian bullet.