westerner wrote on Nov 25^th, 2013 at 12:08am:


Ahhhh, comrade Joe, fellow noodlehead -

The goal is of course to shoot right-much accurately.  I'm simply trying to control each element to where I KNOW it's the best I can do.  Lord knows that I'll get sloppy as soon as I do that.   

I could have posted lists of numbers.  But the graph shows the WEIGHT of each bullet.  The little ups and downs show the variation between each bullet.  The rising or falling trend also shows variation in weight - but from a different cause.

I am presuming that the individual weight variation is from # of seconds at each stage; while the trend up/down is from the heat of the alloy or mould changing.

Hmmmm.  Mixed emotions on posting this one.  I cast 40 some using a ladle for the first time in decades.  HATED it.  (I had a system that was tuned - fill it, let it cool, cut the sprue (gently with gloved hand), drop the bullet - LIGHT tap if needed with soft faced hammer, refill.)

NOW I gently hook up the ladle, roll the pair 90 degrees, wait five seconds, observe alloy won't flow out of the ladle because it's frozen, observe the alloy in the mould is frozen solid (no longer sucking in), and by this time the sprue is HARD - cut it and beat the mould with a hammer to get the bullet out.  Frustrating would only start to describe my feelings.

BUT, the bullets looked GOOD.  AND there were strings of weights that were very close.  Did I mention that the sprue place loosed up towards the end?  Did I mention that I had to tighten one of the retaining screws holding the mould to the handles?

In summary - potential is there.

gunlaker wrote on Nov 26^th, 2013 at 12:52am:


Ahhhhh.  Now the dilemma.  The string:
12      349
13      348.6
14      348.6
15      348.8
16      348.6
17      348.5
proves to ME that I can do +/- 0.2 or so.

The dilemma is whether or not I can read that in terms of dispersion on the target.  To test that I have to DO it for large numbers of bullets and get ALL OTHER variations in dispersion limited to be able to compare one group of +/-0.2 with another group of +/-2.0 variation. 

If I can get to that point, then it's a choice of value - is it worth the cost?  For some applications it will be.

The trend down and up of the weight (caused by the temperature of the alloy) is still there - soon to be tamed with a PID.

Again this session was a genuine PITA.  It requires refinement (adjustment of times and temperatures to get the bullets to drop easily as before).

gunlaker wrote on Nov 26^th, 2013 at 10:01pm:

I agree, with this....to me, when I have as perfect as a bullet as i can cast, then I can look elsewhere If i am shooting  bad groups....I have learned to cast what I feel is a good/Very Good bullet, so, the only time I've had a large variance in weights and other defects was in the beginning of learning to cast. As far as shooting bullets with a large weight variance, I've only done that a little in the beginning of shooting lead bullets mainly when I bought them from bullet casters already cast and lubed.

Terry

We're in agreement.
BUT the fact that I had a string of several in a row (#13 to 17) that were MUCH better that the rest IN THE MIDDLE of fighting a stickey mould release issue (having to HIT the handles insted of just tapping them to fall out) I find it remarkable.  The rest of the series is WAY out of control!

It was like starting over.  OK, PID controller will be installed and the process will get refined (a LOT).

I am weighing afterwards.  Hitting the mould handles to extract the stuck bullet is way too frustrating let alone just time consuming.

What 40_Rod says makes sense with respect to heat.  I think that the bullet will shrink just a little as it cools.   

  I found a couple of years ago that when bullets stick I can usually get them to drop nicely by simply waiting longer before opening the blocks.  My moulds vary quite a bit with respect to timing, but on my big .45 cal. BACO moulds I wait for a count of ten after cutting the sprue before opening the blocks.  On my little Hoch moulds I go almost as fast as I can.

Chris.

CW with a wooden toothpick drag it accross the sharp edges
including each lube groove. If you have some slight burrs you can work them out. Don't even think of using anything metal, razor blade etc. You might go through a half dozen toothpicks maybe more but they won't damage your mould and will get rid of them should that be your problem.

JLouis