% culls when casting optimally

[milkman]

I have found that the heavy bullets are usually slightly larger in diameter, which may explain why they shoot well. Just my experience

[greenjoytj]

For me the bottom pour pot gives me a lot of defective boolits ... the dipper , open top pot and pressure casting gives me mostly perfect boolits.
Gary

What is pressure casting?

[Cosmic_Charlie]

There can be hiccups even when everything is running well. I have reached the point where with a properly pre heated mold I can get good boolits immediately, once I get the rate of pour adjusted.

[JoeJames]

I have not been casting very long, but I was thinking while casting yesterday that if a beginner asked me which mold to start with, I'd recommend big short boolits like my Lee 430 240 grain. I was grinning like a possum after a very good run with those... better than 90% maybe 95%. And BTW using a ladle. Emboldened by that I got out my double cavity mold for 98 grain 32 caliber swc's ... and was chastened and not near as cocky ... more like 40% culls.

[gnappi]

The only things I reject are any from a short pour without a base and any with a wrinkle that goes all the way up and down the length of the bullet.

Everything else goes down range. PC covers most sins on the bearing surface and if I get a snotty tip or two I am OK with less than perfect tip

[hickfu]

My OCD wont let me see a defect and keep it But I have learned to keep the pot at 720* and turn the stream down so it takes longer to fill the cavities, It cast more consistent and much closer weights that way as it does not trap any air in the mix. Every one of my 9mm bullets (120lbs that I cast the other week) are within 1 grain of each other and probably closer.

[Rich/WIS]

All my molds are either Lee 6 cavity pistol molds or NOE 5 cavity rifle molds. Preheat with a hot plate and first couple of pours usually reject maybe half or less, after that seldom get a reject.

[kevin c]

What is pressure casting?

Rather than letting the alloy stream free fall into the cavity, the spout of the ladle or the nozzle of the bottom pour is pressed into the sprue plate opening. That gives increased filling pressure and additionally there's no air cooling of the alloy entering the mold.

[JonB_in_Glencoe]

Once in the Zone...

a month ago, I cast up some 9mms. about 1000 of them.
Obviously I am not counting the first 10 or 20 pours into this NOE 5 cavity mold.
I visually sorted them as I ran them through the lubesizer, there was 30 that were culled...but honesty, those culls were plenty good enough for pistol boolits. I was quite proud of that, it's usually more like 100 that I'll cull out for that size of a batch.

[Aunegl]

After a four hour session, 15% are culls.

[David2011]

Maybe it’s because the majority of my boolits are the short fat (170 gr .40) type my rejection rate is pretty low but no idea of percentage. That’s in spite of using a Lee 6 cavity mold. I also use a hot plate and try to keep a steady pace which is fairly necessary with the Lee six bangers. For me it’s kind of a dance between keeping the mold temperature good and keeping the spout from freezing.

Using iron or steel molds the rejection rate is very low once everything is up to temperature, regardless of the boolit shape. I only cast for handguns for now so no long skinny boolits. I’ll eventually cast for .375 H&H. Long but not skinny.

[kevin c]

Soooo...high BC rifle boolits (long and skinny) are technically more difficult to cast well, or is it more that fewer defects are accepted, leading to a higher reject rate despite the same percentage of flaws in the same number of pistol boolits? Could it be # of cavities or mold material?

[charlie b]

I think it is both. They are difficult to cast well, and, I want fewer defects in those bullets.

My theory on the difficulty is the temperature differential in the mold. The relatively thin bullet is affected by a mold that is different temperatures over the length of the bullet cavity.

[rintinglen]

I’m riding with Charlie B. On this one. Long skinny Boolits are harder to cast well, and the degree of perfection required to shoot a 2 inch 100 yard group is proportionally much greater than that required to shoot a 2” group at 15 yards. While I can’t specifically pin exactly why it is so, a 311-467 will more likely have rounded edges, wrinkles, and other defects than a 311-465, which is about 40 grains lighter. Charlie’s theory makes sense to me.

[charlie b]

Yes, my pistol bullets I accept a lot of minor flaws, but, none in the base. Fist size group at 25yd is fine. I usually do not even shoot groups, just 6" steel plates. OTOH, I am not happy with my cast rifle bullets unless they shoot 2" or better at 200yd.

[McFred]

I cast 622 "keepers" yesterday, I rejected 15 other projectiles. 25 of the keepers I set aside as they'd be fine for pistols, but I'd hesitate for longer range carbine use. That's less than 2.5% reject. I qualify that percentage, since as I cast, I toss sprues and obviously bad projectiles back in the pot.

[Hanzy4200]

For me it all depends on the mold. I have well behaved molds that give 98% keepers, and I have PITA molds that might squeeze out 80%.

[Shiloh]

I'm a lot more picky about rifle boolits.

Shiloh

[fredj338]

I probably run a 2-3% reject rate but I may be more picky than some.

[ACC]

I usually have 10 to 15% rejects.

ACC