sharp, crisp edges

[Mayo]

I'm having trouble casting boolits with sharp band edges, and I know this can be a challenge for many of us. There's a very helpful thread from a few years back (2017) and I'm ready to put some of those suggestions to use. However, I'm wondering if size really matters. I'm casting .25 and sometimes .22 caliber boollits. The .25s are for breech seating in a 25-20 Single Shot. I have two molds, one Mos and 1 Hoch. Is it inherently more difficult to properly fill molds for tiny boolits?

[Randy Bohannon]

Melt temp.? Alloy ? Are you preheating the mould ? Yes sharp bases affect bullet performance, when you have sharp bases and lube grooves it equates to everything else is good.

[rancher1913]

add a little bit of tin, aka pewter.

[country gent]

Also another issue with little bullets is the blocks have more mass and less heat going into them. You may want to pre heat the blocks, run temps a little hotter on the alloy and cast faster. Also pour a big sprue to keep sprue and base hot as long as possible.

Depending on your alloy a little tin might help.

Make sure the blocks and vent lines are clean, the sprue plate is flat and moves free. Sometimes a light bevel stoned on the top edges of the blocks help but it dosnt take much to make that extra vent line.
While most cast around 700-725* with the small bullets you might go up to 750-775*
Heres what I meant above. Your 22-25 cal bullets are 50-90 grns weight while most bullets run 150-500 grns and then the bigger cavity is replaced with more steel to keep hot in the smaller bullets.
Run fast and hot when bullets start getting frosty slow your cadence or lower temp.

[Minerat]

I do 0.172's the key it to keep the mold hot. Even with a 4 gang casting fast with 775° alloy I have to go back to the hot plate every 10 or so casts for a few minuets. I finally started using 2 molds a 357 while I let the little ones reheat.

[gwpercle]

To get perfectly filled out & sharp edges ... I gave up on the bottom pour pot and went back to filling each cavity with a spouted Lyman Ladle ... filling the ladle , pressing the spout tightly to the sprue hole , quickly inverting the nould and ladle to make a "pressure cast" ... then leaving a generous sprue puddle on top ...
the puddle is very important to geta perfectly filled out boolit !
This is called Pressure Casting and will give you good boolits .
When you want perfection ... do not try for speed casring ...
Slow and Steady wins the day !
Gary

[Mayo]

For some darned reason I lost the first attempted reply.
My usual casting temp is 750 degrees. Alloys i use most are 30-1 and 20-1, but sometimes a bit harder like Lyman #2. I guess I need to up the temp and try to keep the molds hotter. Thanks for your reply.

[Mayo]

To all of you,
Many thanks, you've given me some good things to think about and try. I appreciate all of it.

[Tripplebeards]

Getting your mold and lead super hot is key.

[ebb]

Tin