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kimoleto
05-22-2021, 09:40 PM
In the morning I was making some .30 cal slugs for my condor, I built the press following the forums post, it works like a charm. I had to experiment a lot with dies, pins, punches, ejectors... but eventually got excelent results. Yesterday I changed the press arm for a longer heavier one. Today I started making my slugs far easier due to the longer arm, after a while I noticed the lead was flowing into the central hole of the die (where the ejector/hp rod rides). I was expecting a broken rod but it was intact. The resulting slugs have a cylindrical protusion insead of a hollow cavity. I tried different ejector shape, lenght same result...what can be wrong? besides the longer arm theres been no change on the press/dies/punches . IŽve made some 500 slugs without a problem (after initial experiences). I use pure lead, I made the dies and work OK, ejectors are made of spring steel or stainless steel. Any ideas?

contendernut
05-23-2021, 07:34 AM
Back off your base punch or decrease your core weight. You are trying to fill your die with too much material for the cavity size.

If the lead can’t flow out your ejection pin hole, a cracked die may happen.

kimoleto
05-23-2021, 09:01 AM
They are air rifle slugs, no jacket; anyway its a good idea, bleeding holes are working OK, but IŽll try raising the punch a little I believe that by increasing the lenght of the arm IŽm now applying a lot more pressure and lead is flowing faster. Thank you for sharing.
More info, I use pure lead (very soft), they are air rifle 30 cal slugs, 40 - 75 gr and use pure lanolin as lubricant, very little of it.
Can anyone provide me with ejector rod lenghts? all my toys are DIY, got some measurements from CorbinŽs page (diameters) but lenght is not provided, not sure if my ejector/hp rods are the problem, they were working fine but the change in pressure (due to longer arm) might be the issue

jimrk
05-23-2021, 01:22 PM
show us some pics please. slugs, dies, rods.

kimoleto
05-23-2021, 02:23 PM
This is how my slugs used to be:

283369



This is how they are now

283370


ejecting rods

283372

Red River Rick
05-23-2021, 10:40 PM
The clearance between your ejector punch and the hole in your forming die is too much.
Hence the lead flowing between the two.

The ejector pin/rod should be no more than 0.001" - 0.0015" smaller than the hole in your die.

RRR

kimoleto
05-23-2021, 11:37 PM
IŽll check them tomorrow, they might be worn or wrong since the begining. Thanks for your advice.

jimrk
05-25-2021, 10:08 AM
Maybe with the longer arm you are creating pressure faster and you are getting 'blow by' at the punch AND the bleed holes? Go slower or put the old arm back and see what happens.

kimoleto
05-25-2021, 01:47 PM
IŽve been kind of busy... the idea of measuring the rod and the die hole, sound logic. I had the same idea about the arm... longer arm increased pressure, bleed holes not working properly....

kimoleto
05-25-2021, 06:18 PM
jimrk It worked!!!! a shorter arm resolved the problem. I have my hp slugs back. Thanks everybody for your time and ideas, sizes were OK, fit is tight and within spec. An overpressure issue?

jimrk
05-25-2021, 10:07 PM
Good to hear. Might try a bigger bleed hole(s) to get the pressure to use the bleed hole(s) before blow by. Just a WAG on my part. Lead flows from pressure but it needs to heat up so it can flow. Might heat up at the punch before it does at the bleed hole.

kimoleto
05-26-2021, 09:18 AM
A detailed investigation of my recent failure lead to the following: the Corbin press uses an 18" arm...mine is (was) 125 cm. How could I be so wrong? After a while I finally discovered that 18 inches are 45 cm, 45 inches are... 125 cm. I got a little confused with inches and cm...
Bleed holes are 2 mm (+/-).078"....hope I did not mess that one to

Red River Rick
05-28-2021, 04:36 PM
Properly swaged HP bullets should look like this, without any bleed around the HP.

283620

RRR

kimoleto
05-28-2021, 09:52 PM
They really look nice, I keep practicing, I dont have a lot of tooling and never got any instruction on machining, its all diy and learn it by yourself. Thats why I value your advice so much.

kimoleto
05-29-2021, 02:43 PM
Rick do you make a taper on your HP pins?

kimoleto
05-30-2021, 12:28 PM
Just noticed that changing the location of the hole for the spring pin in the punch the sinchronization changes and I get clean and deep hollow pointed slugs, even with the long arm. The hole is the red dot on the drawing (new location is about 28 mm from the bottom of the punch), the other circle is the retaining screw for the pin. I made the press based on the forum post...no instructions included and no previous experience so a lot of experimenting is a must.

283735

jimrk
05-30-2021, 06:51 PM
were you just using the set screw before with a deep hole so the punch could move deeper into the base?

kimoleto
05-30-2021, 09:11 PM
Before all this I was only using (adjusting) the top punch. I had no idea the lower punch could be adjusted, I was trying to make a longer lower pin and started playing with the punch size (lenght) and hole location

Red River Rick
05-31-2021, 11:43 AM
Rick do you make a taper on your HP pins?

Yes, I do put some taper on my HP pins.

RRR

kimoleto
05-31-2021, 12:17 PM
On the way to my job (and back home), thereŽs a spring factory, they sell annealed steel wire in many gauges, IŽll visit them today and check for availability in order to experiment with pin profiles.