Bullet casting weights

[biliff]

This is interesting. 270 grains a 1 grain variance is about 1/3 of one percent. One grain in a .36 is the best part of two percent, and a grain is just 1/7000 of a pound. Your first thought would be it would matter more to a .36 then a .58
When your running ball about what's your reject rate?

Never figured out a reject rate. Most of the rejects come from the first 30 or so castings, probably because I don't have the mold temperature quite right until then.

 

[biliff]

You're free to do whatever test you choose. I did mine and I'm acting according to what I found. I eagerly await the results of your exhaustive, blind testing.

Oh wait, you've already done it.

....If it came out round, it was a go, if not, it went back in the pot. I am pretty much the same way and don't notice a mess of difference between me and my shooting buddies' store bought.

Yeah, that's some real empirical evidence right there.

 

[amcmullen]

Uno676,
You don't need to buy my "Book".
Just remove a wheel weight from one of your front tires and drive speedily down the road. You'll note the wheel will try to leave the axis around which it is turning.
An off weight ball will try to do the same thing.

The rascals.

Dutch

Nobody "needs" to buy the system. But if they want to shoot better and gain forty + years of knowledge, they should. I did and am absolutely happy that I did.

My Traditions shot round balls much better than my T/c. Then last year my traditions group size started to open up. I was convinced that the TC just was not a "round ball gun" and that the new front sight on the Traditions was the culprit . I then bought your system and the light bulb went off...actually a few times.

First was the Traditions. Not only did I get a new front sight but I also started using new swagged balls since my old speer supply ran out. I weighed the new balls and found that they varied by three grains and that out of a hundred balls,2/3 were under the heaviest weight.
I challenge anyone to center the light spot of swagged balls.

The T/C would not give me groups any better than 6 inches at 50 yds. I changed from swagged balls to my cast and weighed balls and was down to a 3" group. Now I am down to a 2" group after playing with patch material. I'm sure I can get a much better group once I find my guns proper patch/ball/ powder combination. After I get my TC figured out then I will work on my traditions.

Furthermore, I believe that a slower twist is more forgiving of off weight balls. The reason goes back to your wheel weight analogy. Drive at a slower speed and the thump is less noticeable. Now run it at 90 and feel the difference. Faster twists would show similar results.

I recently started casting my own round balls. I quickly found that cold molds produced bad balls. A lot of them were easily recognized if they didn't fill out completely. However, many of them looked full but could weight ten grains less! After the mold warms up they become full and are consistent in weight. As I cast I would drop them in line on a towel left to right then weight them. As you would suspect the left (first casts) would vary greatly then get better.

Believe what you want. I'm a believer of weighing balls because of my experience and physics.

 

[Donny]

Say.. I am curious...what is your cull wt.?

+ or - 2 gr. or 3?
Or what?

 

[amcmullen]

Say.. I am curious...what is your cull wt.?

+ or - 2 gr. or 3?
Or what?

Sorry, I was so busy preaching that I never answered the question. I only recently started pouring so i weigh every ball and record their weights. I cull everything that is under one grain under the molds posted weight. When I have weighed 50 or so I look at the numbers and can quickly see what is the heaviest. I use that number and then re-weigh and cull everything under one grain under that heaviest weight.

I did that twice for each mold and keep the records in my binder along with Dutch's book. In the future I will use one grain under the heaviest as my cut off point. Anything under goes back in the pot...actually I think I am going to keep them and do a little testing... :hmm:

It doesn't take too much time and I enjoy doing it. I like knowing that every ball is up to my standards.

 

[amcmullen]

Trust me, when my minimum weight is 180.5 grains it is REALLY hard to get rid of the ones that weigh 180.4 grains...but I do it

 

[M. De Land]

Weighing balls without micing the diameters is pointless.
If one puts a small index mark inside the mold cavity near the sprue you will have a reference point to mic each ball in the same place.
Now you will be actually making some head way in weight consistency.
You will be surprised how often the mold halves do not come completely together and produce an over size and thus heavy ball with no void at all in the cast.

 

[amcmullen]

Dutch, I think what happens is that voids, in an other wise perfect looking ball almost always occur under the sprue and most folks center the sprue toward the muzzle when seating which maintains the balance even though a bit lighter in over all weight.
This might effect vertical trajectory a bit but at the shorter ranges would probably go unnoticed.

I agree with you to a point , but regardless I don't want to chance it since there is no real way to tell.

I think that a legitimate question for everyone is what is your definition of accuracy? Is it a 1" group at 50 yds? Or are you happy with a 6 inch group?

If you are content with a 4+ inch group (and that is perfectly fine) then weighing and culling balls may be a waist of time.

 

[amcmullen]

Weighing balls without micing the diameters is pointless.
If one puts a small index mark inside the mold cavity near the sprue you will have a reference point to mic each ball in the same place.
Now you will be actually making some head way in weight consistency.
You will be surprised how often the mold halves do not come completely together and produce an over size and thus heavy ball with no void at all in the cast.

Good point!

 

[amcmullen]

Now I have to go buy a caliper ...

 

[M. De Land]

You'll need it any way for micing patch material and a thousand other things.
And once you get the feel of it you can be plenty accurate enough using a caliper to mic patching.
I use both the caliper and a 1 inch mic for patch and ball measuring.

 

[tenngun]

I gotta say a true double blind test would give us the most accurate results. How ever in practical life and application I doubt very much that your knowledge of what ball was what changed your results.
A pharmacy or a company making ball or what have you might fudge results for sales. However people don't cheat them selfs for no real reason very often.

 

[uno676]

So if I buy your book you'll sign it right :wink: :bow: :haha:

 

[Idaho Ron]

If your consistently on the heavy side of the moulds intended weight my guess your diameter is going to be very close.

 

[M. De Land]

One of the things you will quickly discover when micing round balls, swaged or cast is that they are not truly round.
For that reason the mold cavity must be indexed with a mark so that each ball can be accurately measured against the next.
I use a small prick punch and make a tiny indent up near the sprue midway between a parting line.
This is where you line up the caliper jaws and measure the widest OD of the ball on that plane.

 

[amcmullen]

Advertised weight for a Lee .495 is 182.07. My heaviest balls were 182.5, 182.5 and 182.09. my last go around the heaviest was 182.25 x 2. The VAST majority were in the 181 range.

 

[amcmullen]

Correction! The Last post was my first and second go around. The weather was cold(40 deg) and I was fighting a cold mold the whole time. The last molding session most balls were 182 or high 181 grain range. This was the cold day. I cant find the good day recordings. I may have just stopped recording since they were almost all identical.

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[amcmullen]

One last observation, I do have a micometer. and just measured a few balls. I had to really take my time since I have a hard time getting it right. I measured a few light balls 181.11 and 181.10 and they measured in at .493. I then measured an few balls that came in at or greater than 182 and they came in at .495. I was careful to measure with the sprue up and the cast marks parallel so that I was measuring the diameter from the deepest part of the molds.

OP, do you have a headache? I know I do.

 

[amcmullen]

I'm still buying a caliper

 

[Canute Rex]

Just today I cast a run of .520 ball with some mystery lead/zinc I've got. The final score was:

Under 200 gr: 19
200-201 gr: 22
201-202 gr: 32
202-203 gr: 16
Over 203 gr: 3

Since I'm shooting a smoothbore and I'm the biggest variable there is, I'm melting the top and bottom categories and shooting the rest. That puts the weight spread at +/- 0.74%. I can live with that.