Casting 101?

[triggertreat]

I have not cast the first boolit yet.  My casting equipment is on the way.  However, Carl (Kenectic45^) has sent me some of his cast bullets from NOE moulds to try in my .357 Slayer.

Below is the mould I purchased to start learning to cast with.  It's a Bob design mould (BBT), and has the weight and HP I'm looking for, for deer/hog hunting (152gr in HP w/40:1).

I have had some good accuracy results with this boolit on paper at 100 yards, but have plans to dial it in even more with tuning, sizing, lubes etc.  There are other lighter boolit moulds I'm interested in from NOE and others for paper punching and smaller game, but I will wait for a discount code for those.

[triggertreat]

Well today was the day I cast my first 100 boolits.  I'll just say I can appreciate those that have mastered this art.  Nonetheless, it was a good first experience for me.  Most of the boolits will be culled, but I did get about 25% I feel real good about.

I had a tough time in the beginning getting the boolits to drop off of the pins in my 4-cavity HP mold.  I found myself pulling them off with pliers, then dumping them back in the pot.  I finally brought out the LP torch and cranked up the mould temp.  This helped in getting them to drop off of the pins.  I can't wait until I get my DIY PID built.  The Lee pot is all over the place with its rheostat temp control. I also have a hot plate coming that will help to get the mould up to temp.

I can see my mistake was to start out with a NOE 4-pin HP mould.  That has to be the toughest type of mould for a newb to start out with.  I should've listened to Kenectic45^'s advice and ordered the 2-cavity instead.  The good news is, if I can master this one, I should be golden on the FN moulds.  For a spell, I did resort to just using only two of the cavities which helped.  I then moved on to using all four.

I will have to figure out why the HP tips don't have good fill out.  My guess is still too cold of a mould, or I'm not pouring correctly, or fast enough.  I'll figure it out.  The good news is that the bases are perfect.

I did size some to .358 and that part was very easy.

[Kinetic45^]

I don't smoke molds or use mold release any more, just boiled degreased blocks.
But I've found that a bit of dry graphite spray just on the pin tips works.  On NOE molds, with the mold open, drop a piece of paper 'backstop' between the block half and the tilted out pins and spray just the cone lightly.

Then, you have to run hotter for HP. I run 740 on the pot (750+ is when you start having issues with the tin) and heat the mold a little hotter by dipping the front lower corners of the mold into the pot for (closed of course) for about 10 seconds.  Then I preheat the spru by putting just a 1/2 inch of the tab into the molten lead for 6 or 7 seconds ( put a little synthetic two cycle oil on that end and the lead will not stick at all to the spru plate).

Cast the first pour, cut the spru but don't dump and if spru lube not applied do so to the underside of the plate VERY LIGHTLY and a swipe across the top of the blocks around the lead showing, getting none to the lead so it doesn't contaminated the cavity. I also put a tiny drop on the spru hinge bolt where it pivits on the block to prevent wear/galling.
Dump and go to town casting at a high rate of speed to keep the mold hot.
If it is a bit cold there will be a bubble form at the tip of the pin.  Or if your not filling right that can happen too but experience is needed there... experiment with different fill rates and angles to see what worked for you

[triggertreat]

Thanks!   I'm thinking i had the pot too hot and the mould got too cool fiddling with trying to get them to drop off the pins.  I could tell having the correct temps are the key to good cast.  The good news is I didn't get any burns to myself on my first run.  I'm certainly not use to working with these types of temps.  I was very careful to avoid pot splash, etc.

[Kinetic45^]

There should be a sticky about CASTING SAFETY and other associated dangers.

Not just burns but fumes and inadvertantly ingesting.

Lead being handled leaves traces on the skin which can be transferred to other surfaces then transported to the mouth, nostrils (pick your nose?) or eyes and enter the body which builds up long term.
I don't wear gloves like I should because I lose too much dexteraty but I don't eat or drink anything in the casting area and wash my hands and face before I do every time I leave the area to do so.

That actually applied when sorting, weighing and swaging bullets too... handling pellets or swaged/cast bullets leaves lead on your skin!  Got tested last year and after 50 years of casting my lead levels are waaaay too high and I was ALWAYS careful!

I have used wax to flux with along with sawdust to cover my melt and keep the tin oxides down and had to learn to always set up in a well ventilated area because the fumes are carcinogenic and will have lead molecules too.  So I always have the air blowing from behind me towards the pot and exhausting out.
Mostly I use the non-fuminf Franklin Flux now and still use sawdust

Years ago I was in the Philippines and watching a guy casting wearing shorts and flip-flops and no shirt and I commented to another guy beside me that you would never catch me mixing molten lead with so much bare skin... about that time he somehow caught the pot edge with the mold and dumped it across the table and enough ran off the edge to dribble on him as he jumped back.
NASTY, no skin, raw meat thighs with some on the tops of his feet and splatter on his belly too.
I may not wear the gloves I should but even in Texas summer heat I wear long pants and shirt!

I am also very cautious about putting lead into the pot because any trace of water will cause a steam explosion, blowing molten lead all over. Range scrap is especially prone to pockets of water!!!!!  I usually set the scrap in a can on my hot plate to preheat and drive off / dry any moisture.

I don't plunk chunks of lead into the melt either when refilling.  I use an old serving spoon I bought at a resale shop to put the lead on then move it to the pot above the surface and tilt it into the molten metal so no splashing. Bar halves I use some old channel locks to lower the lead in.

Small wire gauge extension cords and high amperage lead pots (+ maybe a hot plate too?) lead to you discovering something cavemen discovered long ago - 🔥

Others may use slightly different safety methoids but everyone should be doing it / casting, with thought to safety and living a long healthy life

[Sky]

+1 for safety. When you get your physical you can order a heavy metal test. My doc was skeptical, but I told him I handle lead regularly, and come across other heavy metals. Im always careful, but I do have more than the average Joe. Not dangerous, but it's something to monitor.

[triggertreat]

I put the first casts on a grain scale to see what is going on with the four different cavities.  I believe the spreadsheet reveals the four unique cavities.  Now the trick will be to adjust the pins to bring them closer together.

[Kinetic45^]

Hummm
I'm going to say that after you get your pins closer together, you probably might consider culling anything under 151 gr ( with 1:40 alloy, go lighter with more tin) right off the bat because they are probably underweight due to an internal void caused by a bubble that gets trapped in the solidifying lead. That's why you don't want a turbulent pour and why I try to avoid impinging the stream on the spru plate cone.  Yes, some people say they hit the edge on purpose to swirl the lead in but I found it leads to a lot of weight variation if you ACTUALLY WEIGH every bullet.  Plus you have HP edge fill out problems where a fold appears on the nose of the bullet - will not make much difference at 50 or much you see at 100 but at longer ranges it is just enough imbalance to cause larger groups.  The major problem with a bubble void is not bullet weight but that I guarantee it is not on the centerline and an off balance spinning bullet will not fly as true.
The dilemma is determining if you have a pin depth set problem or bubbles... actually, you should be able to set the pins by eye in their groove with the block half off the handle.  You might be a couple thousands off but it will only affect the weight .2 or .3, maybe .4 but I doubt it.  Use a bright light and a magnifying glass if you have too but with the naked eye most people can see .005 difference (the thickness of the average piece of paper) between two things like the bottom edge of the block and the groove cut in the pin... just set them all the same because the tolerances they were made to ensures consistent length on the other end. Don't bother to chase the 1/2 gr weight for a shallow or deeper pin if all the cavities are casting the same.  So what if you are casting bullets that are .5 heavier than another person if yours are all consistant.?
Because the secret to accuracy in centerfire cartridge reloading, bullet casting or shooting technique is CONSISTENCY.

Also, a lot of precision shooters don't mix cavities at all.  They may use them all but mark the wall of each cavity with a TINY unique scratch and sort first by cavity THEN start weighing per cavity for voids.  Then when they shoot, they zero for that particular weight.  When they run out of that weight the switch to another cavities batch of bullets.  Note that you have to cast many more bullets to batch by cavities, haha.  Casting 200 bullets in a 4 cavity mold woul only give you 4 ea 50 bullet batches pre culling and weighing😁.
When I used to do that I cast 2000 bullets so I had batches of 500 from each cavity!  Easier to just buy two or even one cavity molds for lots of reasons if you stop ego obsessing about "production numbers" and go for quality.  And learn to be in a Zen state because casting can be relaxing instead of stressful! ! !

[triggertreat]

Yes, all of these will be culled.  I just wanted to get some sort of view/idea/comparison of how my first run did.  I won't be bending anything until I get a handle on the pour, but will take a closer look at the pin alignments.


I'm not able to use the Lee guide due to the pin brackets, so it's all freehanded.  I did try to center up the cavity entrance before each pour, but can say I had trouble doing that.  I think I will need to increase the pour rate as well.  I did have the stream coming out fairly slow to prevent overrun on the sprue and splash.  It's a fine line there to get the actual pour just right.  I need more practice for sure.  I still consider the first trial still went fairly decent and learned a few things.

[Kinetic45^]

Yes, all of these will be culled.  I just wanted to get some sort of view/idea/comparison of how my first run did.  I won't be bending anything until I get a handle on the pour, but will take a closer look at the pin alignments.


I'm not able to use the Lee guide due to the pin brackets, so it's all freehanded.  I did try to center up the cavity entrance before each pour, but can say I had trouble doing that.  I think I will need to increase the pour rate as well.  I did have the stream coming out fairly slow to prevent overrun on the sprue and splash.  It's a fine line there to get the actual pour just right.  I need more practice for sure.  I still consider the first trial still went fairly decent and learned a few things.

I've actually found I get better fill out with NOT stopping the pour too soon and getting a small puddle on top of the spru plate.  You want a BIG puddle to put heat into the plate so the lead does not solidify too fast so the puddle can feed a bit more down into the cavity as the lead cools and shrinks.  If you starve the puddle you will notice you get pinhole voids in the bullet base.  What's happening is the lead touching the mold solidifies first from the outside in and it shrinks.  Without some extra you end up with a hollow core bullet, that's actually the purpose of the cone in the spru plate, it's not really a funnel, it's a reservoir! (And a cutting edge as a dual purpose) But in reality it's too small and hence the puddle on top!
Also, I let the stream continue a second longer and even let it overflow off the side a bit as that extra pressure makes the base of the bullet fill out perfectly every time and so I don't get a tiny radius base edge which gives weight variation.

Hey, the extra large spru's just go back into the pot and don't slow production down much, haha.

[triggertreat]

One thing fore sure is that all of my bases are near perfect.  Almost like a mirror, very flat and filled out.  The tips on the other hand need much work.  They are not even all the way around, but are smooth.  It's like an 1/8th to a 1/4th of it has a shallow dip in it.  I would say close to 90% of them are this way.

[triggertreat]

Today was my second attempt at casting .357 cal slugs for the Slayer.  The casting went much smoother, and the slugs look much better than the first attempt with having a fully filled out HP tip.

This was all thanks to Knifemaker Mike and his input regarding fluxing, rendering, temps and pins to mention just some of his years of knowledge shared via the phone this morning.


I really do appreciate all of the tips received via the phone and on the GTA from Mike and Carl (Kinetic45^).  These two have really shortened my learning curve on casting slugs.  I feel much better going forward having had their knowledge shared with me.  Thanks fellas!


I probably cast close to around 350-400 today!

[triggertreat]

According to Chairgun, it looks like I can get away with a couple grains of weight difference out to 100 yards with not much of a POI difference.  I'll have to do some actual testing/shooting to know for sure if this holds true or not.

Here are the weights on a few I sized to .357

[Hobbyman2007]

Those new bullets look great Keith . How are they shooting ?

[triggertreat]

Those new bullets look great Keith . How are they shooting ?

Thanks!  I have no clue how they group just yet.  It has been raining for days around here and more is expected.  I am hoping for good results.

[KnifeMaker]

You are very welcome Keith! and Those look fantastic. Not bad Sir! Not bad a all!!!


If you hit a snag, I'm here most of the time now days. LOL!


I was in the same boat when RC guided me along the path of the "Silver Stream". And what a journey it has been. 

[triggertreat]

I received my ordered hot plate and electronic BBQ thermometer today. It's the same thermometer NOE sells so the probe fits in the mould.

I ran a test today using both, and this is going to work very well with heating up and tracking the mould temp.

I also received a new set of mould brackets.  I polished the pins and put these on.  I'm looking forward to my next cast with these new items.

My focus now will be fine tuning my process for more consistent slug weights.

[Sbak]

The probes make all the difference, just remember the pins will take longer to warm up than the mold block.

[triggertreat]

I cast another ~ 500 today!  I'm starting to dial the weights in more evenly now.

The new hot plate and electronic temp gauge really helps to keep the temp up on the mould.  I'm still waiting on the PID controller from China for the Lee pot.  My actual pours are not yet consistent, but am working on that.  I also paid more attention to the rendering of the lead/tin along the way.

I sized at random a handful or two out of the large batch to .357 and .358 to check the weights, and to have for test shooting groups.  I shot a few .359 in my indoor pellet trap and had no trouble seating or shooting them in the Slayer.

Here is my sample batch that I sized:

[triggertreat]

I am really pleased with the cast results from yesterday. The slugs are well filled out and have flat tips and bases.  I have been using a piece of copy paper to smooth out any burs I find, which seems to be working really well.  I am not sure how they stack up against the pros, but they are much improved verses my first casting attempt.

 I have been weighing and sorting them by 1grain weights.  I am getting lots of 152 and 153 grain weights, and less of the 154 and 151 weights.  I am sorting them by 1 grain weights in separate tins so that when I shoot a tin all will be within 1 grain or less of each other.

What I don't know is if this is normal results with a four cavity mould or not.  I might start tweaking the pins at some point to see the results.  I am not sure how these results I am getting stacks up against the pros.

Anyways, I am having fun!  I will soon be testing these in .359, .358 and .357 diameters at the range...