JohnH
03-27-2005, 11:19 PM
You're going to think I'm nuts, but I cut the surface "inclusions" of the bullets dropped from my Lee 375-250-RF by at least a factor of 4.
I don't know what prompted me to do this, but I began to shake the mold a little after I had stopped the stream and the sprue was still wet. Not so much shaking as to knock the sprue off the plate, but enough to kind of pancake or flatten it. I would shake it till the sprue hardened. Air inclusions on the base and on the surface of the bullet all but dissappeared. I don't want to put hard figures on it at the moment, I didn't do this in any scientific kind of way. I just kinda stumbled on it. I have noticed that something on the order of 1 in 5 to 1 in 7 bullets would have a gas hole in it somewhere on the surface. As I was casting tonight my mind did one of those "Gee I wonder" things and I began to lightly shake the mold once the sprue was formed. ( a rocking side to side motion)After about 30 or so casts, I realized I wasn't seeing any inclusions. So I scooped that batch out of my way and cast about 70-80 more bullets. Sure enough, I was only seeing an inclusion on about 1 in 20 bullets.
I'm gonna shoot these two batches of bullets and see if there is a statistical difference in the groups. I don't have a scale that will weigh the bullets outright, I got that Lee scale that will only weigh 110 grains, good for powder charges but little else.
So here are the parameters,
The Lee 375-250-RF is a single cavity mold for a 250 grain bullet
I bottom pour useing the Lee Production pot
my casting rythem is something like 2 or 3 cast per minute, I can get 120-180 per hour if I stop for nothing with this single cavity mold
The alloy is WW with 1.6% tin added (60 lbs WW to 1 LB of 95/5 lead free plumbers solder
I don't know my cast temp, but the sprue goes from wet to chilled in about 3 seconds. The bullets are not always fully frosted when they drop from the mold but are by the time I drop the next bullet.
It is going to be interesting trying this with a 2 cavity mold, but it seems worth the effort, at least at present
I don't know what prompted me to do this, but I began to shake the mold a little after I had stopped the stream and the sprue was still wet. Not so much shaking as to knock the sprue off the plate, but enough to kind of pancake or flatten it. I would shake it till the sprue hardened. Air inclusions on the base and on the surface of the bullet all but dissappeared. I don't want to put hard figures on it at the moment, I didn't do this in any scientific kind of way. I just kinda stumbled on it. I have noticed that something on the order of 1 in 5 to 1 in 7 bullets would have a gas hole in it somewhere on the surface. As I was casting tonight my mind did one of those "Gee I wonder" things and I began to lightly shake the mold once the sprue was formed. ( a rocking side to side motion)After about 30 or so casts, I realized I wasn't seeing any inclusions. So I scooped that batch out of my way and cast about 70-80 more bullets. Sure enough, I was only seeing an inclusion on about 1 in 20 bullets.
I'm gonna shoot these two batches of bullets and see if there is a statistical difference in the groups. I don't have a scale that will weigh the bullets outright, I got that Lee scale that will only weigh 110 grains, good for powder charges but little else.
So here are the parameters,
The Lee 375-250-RF is a single cavity mold for a 250 grain bullet
I bottom pour useing the Lee Production pot
my casting rythem is something like 2 or 3 cast per minute, I can get 120-180 per hour if I stop for nothing with this single cavity mold
The alloy is WW with 1.6% tin added (60 lbs WW to 1 LB of 95/5 lead free plumbers solder
I don't know my cast temp, but the sprue goes from wet to chilled in about 3 seconds. The bullets are not always fully frosted when they drop from the mold but are by the time I drop the next bullet.
It is going to be interesting trying this with a 2 cavity mold, but it seems worth the effort, at least at present