Why is ladle pour better than bottom pour?

[bushwacker2]

I would like to help you Wade but my computer skills are not up to posting a photo on this site, and there are no 10year olds around. I have managed to do it sometimes on email.

Mike

[Whitehorse]

Last year I got a Lyman Mag 25 bottom pour. It took a while to get it working but here's what I found. The real blessing of this pot is a limiter on the lead feed lever. It has a mould guide and stop so your mould is in the same place every time. I set mine so it pours in the center of the spru plate hole. By setting the limiter to just right it will cast perfect bullet every time. I pre heat my mould on a hot plate and recycle the first 3 bullets.

[Clarence]

Whitehorse,

It sounds like you may have hit on a promising method, but, as others have mentioned, the head pressure (hence the flow rate out of the bottom pour spout) will vary considerably as the level in the pot changes, and that introduces a different but significant variable.

What is the total weight variation for a casting session, say 60-100 bullets, cast with your bottom pour method and culling only for appearance, and what percentage of the bullets fall within a 1 grain range?

As Woody said, he never could get the cull percentage low enough with the bottom pour method, while good experienced casters can get almost all their bullets in a 1 grain or smaller range with a dipper.

I use a dipper and cast with a clock to keep the mould temperature as close to a constant as possible. If you look at thermal expansion over a 50-75 degree mould variation, you can get significant weight variation with bullet diameter and length differences in only fractions of a thousandth. I'm sure Woody casting cadence keeps the mould temperature consistent. Like Woody, no longer weigh my bullets because all virtually all that look good fall in less than a 1 grain range, with short-term variance (say 15-20 bullets cast sequentially) often have less than a half grain variance.

Clarence

[Whitehorse]

I also use a clock and cadence. You can't throw all casting discipline out the window. I cast 3 to 4 hundred bullets a time and weight them all. I do all my casting in the winter and pan lube them too. That way I don't have to cut into outdoor stuff and cast when it's nice out. I had a good year too.

[Ted Bell]

For those using a clock, can you share the times you are using?
Can anyone share what mould temp I should maintain?

Thanks,
Ted

[Clarence]

Ted,

For most moulds, with lead temperature in the 780-800 degree range and temperature in my casting shed <55 degrees, I use 40 seconds. "In on 12; out on 6; in on 8, out on 2; in on 4, out on 10; repeat ad nauseum. I have a fan on the mould for ~15 seconds (my fan is a cheap bathroom fan with a 3" ell pointed toward the mould, which sits on a 4x4; the end of the ell is 3-4" away from the mould), and adjust the distance from the ell based on how long the sprue takes to soolidify.

Clarence

[desert deuce]

CASTING BULLETS FOR SERIOUS MATCH SHOOTING (Remembering 90% of successful shooting is mental.)

Casting .44 or .45 caliber grease groove bullets weighing over 500 grains weight as cast by dipper method.

Once the thermometer says at least 810 degrees and is constant for a few minutes, I start casting with a preheated mould.
Watching the sprue go from liquid to solid on top of the mould blocks sprue plate varies.
If the nose of the dipper sticks to the top of the mould sprue, the mould is too cold.
Once up to casting temperature for the mould, that time varies less for the sprue to harden.
Usually when the dipper nose does not stick to the sprue on top of the mould the mould is coming up to casting temperature.
I set the mould down on a hotplate and wait 10-15 seconds while taking a second look at the bullet just cast.
ALWAYS open the sprue plate with a gloved hand.
Usually, I don't bother with the first 3 to 5 bullets from the preheated mould, put them right back in the cut sprue pan.
Starting with bullet #6 I look carefully at the base of the bullet before opening the mould blocks.
If the sprue cut on the base of the bullet is a divot or smeared past the edge of the bullet base I cut the sprue too soon.
If a divot I discard the bullet to the sprue pan.
If the base is sharp and even around the circumference it is put in the keeper pan, if not, back in the sprue pan for remelt.
All bullets cast before adding alloy to the pot stay in one pan, next bullets in their own pan.

I weigh the last 10 bullets cast from a pan, take the average of those weights. Half a grain either side of median is for score shots,1.5 grains either side of median separated as sighters. Fact is even to 1000 yards I can't tell any difference in accuracy. Mentally, I need the assurance that the bullet is the best that I can cast and shoot.

Yes, I weigh MATCH bullets and MATCH sighters. I feel it necessary for mental preparation, not necessarily for accuracy per se.
Out to 500 Meters as long as the bases are even cut and sharp around the edges variations up to 3 grains don't seem to matter much, if at all.

It is that occasional bullet that is more than 7-8 grains from median weight that keeps me weighing MATCH bullets. It is those bullets that I am looking for to ease my mind when I fire that last record shot at 1000 yards in the World Championships when only two points down for that relay. I have to know that light bullet is not the one chambered in the rifle at that moment when I break the shot. I don't want that thought even briefly entering my mind if that bullet impact is 3 feet from point of aim. I have to know that in all likelihood the bullet was not at fault.

Fun matches and practice, especially less than 600 yards, 5 grain variation probably won't matter much as long as the bases are good.

For serious MATCH shooting, it is what you individually are prepared to accept mentally that matters.

[mike herth]

Very helpful discussion. What screws up my cadence is the bullet not dropping from the mold, very frustrating! How do you minimize that? I clean the blocks with brake cleaner before starting but after about 20 bullets or so the sticking begins in earnest.

[Ray Newman]

Some my find the "8 Phase Casting Cycle" useful: http://www.longrangebpcr.com/Part1.htm

[Clarence]

Mike,

What kind of mould? I experienced that seriously with several Lyman moulds that were cut off-center. Replacing them with custom moulds cut way down on the frustration factor.

With most of my custom moulds, a firm rap on the mould handle hinge pin before attempting to open the mould helps the bullet drop out more easily.

The reason the problem gets worse as the moulds comes up to full temperature is that there is less shrinkage. I've also noticed that if I'm casting too quickly and the mould is overheating, the bullets don't fall out nearly as well. Again, I attribute to less shrinkage. The answer may be to slow the casting rate. Better 80-90 good bullets per hour with little frustration than 120 with lots of variability because sticking bullets prevented your maintaining a constant cadence. See dd's note about the time to let the sprue harden. With my method, the sprue hardens ~8-10 seconds after I pour, and I don't cut the sprue for another 10 seconds after that.

Clarence

[Kurt]

Very helpful discussion. What screws up my cadence is the bullet not dropping from the mold, very frustrating! How do you minimize that? I clean the blocks with brake cleaner before starting but after about 20 bullets or so the sticking begins in earnest.

Mike what I find 9 times out pf 10 with a mould that the bullet sticks in is the uniformity of the alignment pins and it does not matter who made the mould, Brooks, BA or Paul Jones. I seem to get more moulds from Steve that have sticking bullets and I have always corrected this problem resetting the alignment pins using the loading press to set them at a uniform depth. There is usually a high pin causing the problem.

Kurt

[mike herth]

Clarence, my 45 cal molds are from BACO and BROOKS. I have Lyman and RCBS thermometers, they show a 20 degree difference berween them. You mentioned holding the filled mold in front of a small fan for several seconds, I’m going to try that. And I’ll reduce the casting temp somewhat although I think I’m in the 780 - 820 range. I generally get 40-50 bullets cast/hour.

Kurt, I’ll check out the pin depth. I had not thought of that.

Thanks for the suggestions!

[Gussy]

Do you smoke your mould when starting or when sticking occurred?

[desert deuce]

Cast 62 Paul Jones Creedmoor keepers, Mould #45001 yesterday, 1-20 alloy @ 820 degrees, both my thermometers read the same in the same pot at the same time. I don't know how long it took, I don't pay attention to time or bullets cast per hour, etc. Just bullet quality.

I put the ladle (RCBS) in the pot when I turn the pot on. Don't start casting until the alloy flows freely through the dipper and the pot is up to temperature for at least ten minutes with the dipper submerged in the alloy. Pre heated mould for 30 minutes on hot plate.

It took 15 throw backs before the mould was up to temp and the first bullet to the keeper pan. (It usually only takes 5 or 6.) For me, it takes however many it takes, there is no set number. Some days a high percentage of keepers, sometimes a high percentage of throw backs. I NEVER get in a hurry.

Of the 62 "visual" MATCH keepers 58 were within 0.5 grain weight. 4 sighters were within one grain weight. No throw backs from visual keepers.
Unusual high number of visual throw backs between #1 and #62 keeper. Just the way it went that day. If I only focus on cadence, technique and consistency and ignore production volume about 97 to 99% in the keeper pan are keepers. Some days things just don't go that well. It is what it is.

To shoot good scores, it takes good bullets and good loading technique. Anything can blow a hole in the sky.

[J.B.]

Interesting that most of us are casting at 780+ F and this has certainly been my experience. I too find that there are days when casting 'comes together' and days when it doesnt. If I'm rushing to cast some bullets for an upcoming shoot...then I generally dont get the number or the quality I would prefer. I preheat my mould blocks on a hotplate and rotate them periodically to make sure that sprue plate is hot also. If the mould is too hot and giving me some frosted bullets then I just space the cadence of a couple of casts and all is well with the world. Quite amazing how quickly blocks cool off ( ie. below ideal casting temperature.... but they still burn you quite well ) when you put them aside for a few minutes to do something. I generally keep the hot plate on low until the production is flowing well and I turn it on again and rest the mould on it if I'm taking a break. Unhurried, uninterrupted time ...for me at least, results in a better return on my investment. I guess I'd average 50+ bullets an hour most days. Sometimes its a few more but nothing that another half hr of casting isnt going to produce just as well. Clean mix, preheat mould, thick-preheated sprue plate, pot @ 760-800 F, clock with second hand. If the sprue sets in less than a count of five then my mould & sprue plate are not quite to temperature. I think that consistent 'head' of alloy running through and sitting above the setting bullet is certainly a factor in ladle pour success. I revisit the bottom pour periodically but never had the success and consistency for these 'torpedo' like bullets we shoot.

rgds.. Gavin.