Cut my rejects by a factor of 4 at least

[JohnH]

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

[NVcurmudgeon]

John, I guess I do the same thing you do by shaking, when I tap the mould handle hinge (never the blocks) on the edge of the pot before the sprue solidfies. curmudgeon

[Bass Ackward]

You're going to think I'm nuts

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.


John,

Ah don't worry about the nut thing. We only thought that the first post. :roll:

Well, at least you don't jump up and down. That get's me tired. Sounds to me like you have a venting problem. You could probably clear that up with a teeny, tiney bevel on the top of the blocks where the trapped air could get out without the .... wiggle. Lightly file (just a couple of strokes) on each side of the blocks or use a block of wood with fine emery paper.

Or .... try the jump routine. :wink:

[carpetman]

JohnH---Whether shaking your mold while the alloy is hardeneing helps or not I wouldnt know. Your results seem to show that it does and I could see how it could. For sure if you have a self winding watch,it would keep it wound up.

[BD]

Ya know C-man, it actually brightened my day to see you posting once. Who'd a thunk it.

Now if it would just quit snowing. I'm about out of alloy, and I've got 400-500 lbs of range scrap and WW needing to get melted. BD

[carpetman]

BD--brightened your day to see me posting once? Did things go dismal when I continued posting?

[BD]

I might'a meant to type, "once again", although once is a good number. I always get my best groups by shooting once. BD

[carpetman]

BD--I think you are on to something. One shot groups easily explains all the one hole groups all day long.

[JohnH]

I've tried jumping up and down more than a few times, been a few times I would have stood on my head. The count says it is more like a factor of two, but still thats an improvement. I'll give a try to inspecting the mold and improving the venting.

[JDL]

If you really want to shake your mold, drop a hot boolit in your shoe and you won't believe how good the next cast is :lol: !-JDL

[shooter575]

It is all on how you hold your jaw is what I was told. Takes years to get it done right! :lol: