Star sizing dies

[Shotgun Luckey]

I'm really new to casting and I just inherited an old Star sizer. It seems like a great machine, but I am having some problems. They are probably really easy to fix, IF you know the answers, unfortunately, I'm having a bit of a time figuring them out.

#1 How to adjust the punch to line up the grease grooves with lube holes in the die. Does anyone have a copy of the set-up and adjustment instructions? I'm sure I could work it out from there. I've set and e-mail to Magma asking if they could sell/give me a copy but I haven't heard from them.

#2 I am casting mostly for .38/.357...luckily I received a .357 die with the machine. My alloy is wheel weights with 2% tin added and I'm dropping them from the mould into a 5 gal bucket of water. The bullets "as cast" are dropping at .362 -.363. After sizing the bullets are ending up at .3655 to .3570. This all seems good, but here is my big question....the base of some of the bullets are ending up with a "tail fin" on the base that goes one third to half way around the bullet, I presume from the extra lead the is being swagged. I'm afraid this is going to un-balance the bullet in flight. The punch I have is .355 in diameter that was designed for sizing base first SWC. Do I need a different punch, goto a larger die, or something I haven't thought of yet. I can probably get a guy at work to make me a new punch, but he doesn't do much real precision work (he is a hobby machinist) and he said it wouldn't be cheap. (plus, with his limited resourses at work he wasn't able to figure out the thread size and pitch)

I would be grateful for any thoughts and advise.

Shotgun

[dragonrider]

The thread size is 1/2"-27 tpi.

[lathesmith]

Luckey,
I understand the "tailfin" problem is due to the amount that the bullet is being sized--in this case, .005-.006. I believe some guys get away from the tail fin somewhat by sizing base first, but this of course requires a punch fitted to your bullet nose. Maybe some of these guys will weigh in here, as the most I usually size my boolits is .002" and I have never experienced this problem.
lathesmith

[Shotgun Luckey]

Would a punch that is closer to the die size help the "tailfin"?

[454PB]

If it were me, I'd open up that die some. Most .357's like a larger boolit, most all of mine like .358". Your machinist friend should be able to do this in about 10 minutes. I doubt that a larger punch will stop the tail fin problem, but a smaller "as cast" size will. You don't say what brand mould you are using, but it's unusual for it to cast that large. You can get a 2 cavity Lee for $20 and put the other mould aside or sell it here.

[KYCaster]

Would a punch that is closer to the die size help the "tailfin"?

Probably not. Like Lathesmith said, .005-.006 is a lot to size in one pass. Your fins may be agrivated by a poor finish on the die's ID. I have sized .004-.005 without any fins or distortion, but it puts a lot of stress on the machine. It's better to size and lube with a die near the as-cast dia. and if you need to go smaller then size down in .002-.003 steps till you get where you want to be. The lube makes sizing easier and keeps the lube grooves from distorting.

Before you try to adjust the punch you need to get the lube temp. and pressure set where they need to be. If your lube is too cold or the pressure is too low then any adjustments you make to the punch will just be

Remove the die from the press and look down in the hole where the die goes. You can see the port on the left side where the lube comes out. Crank down on the lube pressure screw till a ribbon of lube starts oozing out of the center of the port.
With a soft lube this will happen at room temp. without getting really heavy on the pressure screw. If the lube doesn't flow then you need some heat. A light bulb in a reflector aimed at the base of the sizer works well. (experiment with the distance to regulate the temp.) When you get the temp. and pressure right you'll get a ribbon of lube oozing out at a rate of ~3-4 in/min.

Now...back off the pressure till the lube just stops oozing out. This is where the pressure needs to be. Push the handle all the way down...a ribbon of lube will squirt out. There should be enough to fill the lube groove(s) on the boolit you're sizing plus a little bit.(usually 3/4 to 1 1/2 in. ribbon) Up near the top of the lube reservoir, on the left side you'll find a bolt with hex heads on both ends...this can be lengthened or shortened to change the stroke on the lube pump to adjust the ammount of lube.

When everything is set up and running, you may have to tweak the temp and pressure to get it just right. I've found that less temp, more pressure works best in most cases.

Now take the boolit you want to lube and lay it beside the die. Line up the bottom lube groove with the highest set of holes in the die. Measure the distance from the base of the boolit to the top of the die. Determine which groove(s) you want to fill with lube and plug all the other holes with lead shot.

Put the die into the sizer and adjust the punch so that when the handle is all the way down, the base of the boolit is flush with the top of the die. Raise the handle and screw the punch up by the ammount that you measured earlier. 27 TPI = .037 in. per turn so if your measurement was 3/8 in. then you need to turn the punch ten full turns plus 1/8 turn(.375 divided by .037 = 10.135). From there, adjust the punch up or down 1/4 turn at a time as needed.

It takes a lot more time to describe the process than to actually do it. After you've done it a few times its easy.

Now, about the .357 die vs. the .363 boolit...I think you'll find that you'll be happier with a boolit sized to .359 so you may consider getting a larger sizing die or honing yours to a larger size.(most Star dies are extremely hard so can't be easily honed, but there are guys on the forum who offer this service) If you decide that .357 is indeed the size that you need, then it should be fairly easy to find somebody here willing (eager) to swap you even for a mold closer to the size you want since most of these guys constantly whine about undersized molds.


I hope this answers some of your questions.
Jerry

[runfiverun]

wow.. 362 there are a few guys that would love that mold..
i aint one of them, my revolvers are happy with 358. and a small bit of tail
really isn't that big of a deal.
unless it is like really sticking out there. 1/8" or something.

[zipdog]

I've set and e-mail to Magma asking if they could sell/give me a copy but I haven't heard from them.

Shotgun

Luckey, Magma used to have the Star manual available on their website for download,
but it's not there anymore. I downloaded it a couple of months ago...send me your email address and I will email it to you if you want it.

Rusty

[Shotgun Luckey]

My mold is a new RCBS MOULD 38-158-CM COWBOY 2-CAVITY .358. I've started to wonder if I'm letting the mould get to hot while casting....doesn't the mould "grow" when it heats up?

[anachronism]

Your alloy can make your bullet diameter slightly larger too. IIRC, high antimony alloys cast larger bullets from the same moulds than softer alloys do. I too think you might try a slightly larger sizing die, I run my .357s through a .359 sizer in my Star, and my punch is .357 diameter. This works very well for me with my revolvers, yours may be different. Only slugging your cylinder throats & barrel will tell you for certain. If your mould "grew" when hot, your bullet diameter would more likely be smaller, not larger.