Ammunition & Hand Loading > Cartridge and Shotshell reloading

Bullet casting improvements

(1/5) > >>

unfy:
Sat down tonight and decided to get more serious about bullet casting.

Did a little bit of reading, a bunch of video watching.  Basically, it was time to move from utility casting (copper plating fodder and PC fodder etc) into something I could do for actual reloading.

So... re-worked casting work area a bit for smoother flow / less movement, and decided to try different procedures (a mix from someone's speed casting techniques and a video).  That video would be:



Don't care for the guy's attitude too much, and with a regular $20 lee mold it's not wholly applicable (ie: can't just nudge some hollow point pins)... but... in general things went much better. 

Upped temperature on pot a little (lee 4/20... set to 7 instead of 6).

Got mold a bit hotter than I normally would have, in particular the sprue plate. The first half dozen breaks using video guy's method still required tapping sprue plate clear and tapping bullets out.  After that, sprue plate was hot enough to not require tapping.

Time between filling mold and cutting sprue reduced to just 2-4 seconds.

Hotter sprue plate and molds seem to nearly completely eliminate the need to tap things with a wooden hammer handle blank.  Hand breaks were easy and clean, and bullets typically fell out of the mold with a slight jiggle.  Only one in 10-15 breaks would require a tap from wood.

The use of the casting pot foot as a heat sink to cool the mold for quicker progression is a great idea.  Faster break, more even temperature control, etc.

Towards the end, I did have some slight sprue plate overheating issues (smearing instead of a clean cut).  Just for fun: I forgot to setup a sponge so ended up slobbering all over a sock to act as a coolant..... :P

Differences from what I do to what the guy in the video does:

I break the sprue over the pot so the lead goes directly back into the pot.  I will prolly stop doing this in order to help reduce splashes.  Also, due to this, I don't "fling" anything heh.

Wasn't dropping into water (in particular with PC and the 400 degree bake... quenching gets undone).


Prolly increased casting rate by a factor of 5-8, and my reject count is sitting at 10 out of the ~1000 cast.  I imagine not tapping on everything a bunch for every break is better for the mold too.

Yay.

unfy:
I'm gonna go ahead and fiddle with alloy stuff on my next go around of casting (and after I get some HP molds)

Some lead free soldier will go into the pot to bring hardness up.  Not terribly expensive (not terribly cheap either), but easy to measure and of known tin/antimony contents.  I was hoping to avoid fidlding with alloying stuff, but it seems like it'd just be a wise thing to do.  Since I'm not producing super high quality lead bullets (see powder coating heh) ... I'm not too worried about getting ultra consistent hardness between batches of bullets... but will endeavor to keep it close anyway (should just remelt the ingots, remix alloy, and recast ingots but whatever).

bkoenig:
I need to watch that video when I get home tonight.  My casting works ok but I could use some improvement to speed things up.  I usually cast with two molds at once and let the sprue cool while emptying and refilling the other mold, but that wastes a lot of time setting down and picking up molds.  Having a way to cool the sprue and using a single mold would speed things up.

unfy:
I found on my ~175-180gr .401 lee mold... I don't need to cool the sprue really.

The video here, and from what I've read...

* Ya run the lead on the warm side.

* fill mold

* set mold on the base of the lee pot (or some other moderate heatsink)

* count between 2 and 4 seconds

* break sprue by hand (for me, i was dumping sprue back into pot, this is gonna change to spare pan to avoid splashes)

* break mold and dump bullets out (typically didn't require any tapping on the pivot bolt/nut)

* immediately go back to filling mold


Due note, I am using smoked molds.

To me, this seemed counter-intuitive... but my bullet quality actually went *up* with this method.  Placing the mold on the casting pot base (or similar aluminum heat sink) sets the bullets and cools off the mold 'just enough' to keep ya casting for extended periods without having to fiddle with mold temperature management (ie: getting fins/etc).  If it looks like your mold is getting too hot, take your '3 second' count on the heat sink to 4 or 5 seconds for a few breaks.  If the mold seems too cold, only do a '2 second count' maybe.

And for the second thing to address - sprue plate temperature. Ya actually want the sprue plate pretty hot when casting in this method.  Ya wanna be able to cut the sprue plate open by hand, and a cold sprue plate makes your sprue harden more quickly, making hand breaks more difficult if not impossible.  I am not sure, but I think the shorter amount of time the lead is on the sprue plate helps keep plate temperature where ya want it.  As I noted with my original post, my sprue plate actually didn't get too hot until near the end of my casting session.  That is, I didn't get any smear cuts on the top of my mold until the last bits of casting... so having the normally required wet sponge near by wouldn't be a bad idea. 

I did have a couple bullets get a dent in their nose... so.... that's something to be aware of.  My current drop place is a cardboard box (from midway no less) with some old jeans in it.  I'll prolly move to a bucket / plastic coffee can of water covered by an old shirt and slit in it.  With the powder coat, I doubt the hardness gained from the water quench will matter (since they're gonna be baked at 400f for 20min later)... but... should stop any deformation stuffs as well as possibly just being easier to deal with.

After adjusting to my routine, it wasn't quite as fast as the guy in the video, but it was getting darn close.

Keeping things relatively hot and being able to break everything open by hand improves speed a lot. Not having bullets stick to the mold is really nice.  Fewer motions, no change-outs-of-tools-in-hand (ie: mold -> wooden/plastic hammer -> mold), and it's easier to get a rhythm.


The only question I can think of to discuss:

Is there a real and identifiable reason to let bullets cure in the mold longer ?

bkoenig:
I think if bullets sit in the mold longer they can drop easier, since they shrink as they cool.  When I cast for my Blackout I have to let them cool longer because that .309 diameter 245 grain bullet is so long and skinny that I have actually had them bend when I drop them too soon.  I drop into a bucket of water, covered by an old shirt with a slit in it.  That seems to work really well.

I drop my sprues into a popcorn tin, one of those big ones that Christmas popcorn comes in.  I don't like dropping them directly into the pot because I feel it can introduce contamination.  Instead I cast until I have a big pile of sprues, then dump them into the pot and flux again to make sure it stays clean.

I'll have to give this method a try.  Right now I use a 1" dowel to cut the sprue.  If I can speed things up by just using my hand that would be nice.  I'm sure I am wasting a lot of movement.

Navigation

[0] Message Index

[#] Next page

Go to full version