How consistent are you REALY???

[Doc Highwall]

I am going to applaud Tim’s efforts to not only investigate the variables in casting great bullets but in also sharing the knowledge of what he has learned. I am doing the same thing with loading dies and posted it quite a while ago but I have not posted an update yet due to the fact that I am still working on it.
Here is a 300 yard group that I shot with the SAECO #315 bullet cast with 30:1 alloy and as you see measures 1.610” with four shots in 1.090” and if I want to eliminate the fliers I will have to do the same thing as Tim. Most shooters would be happy with results like this at 100 or 200 yards but I am not satisfied and I have asked myself the question “What if” and the pursuit for knowledge and perfection continues.

[fastfire]

Tim, Keep up the GOOD work. I presently being overloaded with new to me info but trying to soakup as much as my brain will take. I love this thread!

[MBTcustom]

I am going to applaud Tim’s efforts to not only investigate the variables in casting great bullets but in also sharing the knowledge of what he has learned. I am doing the same thing with loading dies and posted it quite a while ago but I have not posted an update yet due to the fact that I am still working on it.
Here is a 300 yard group that I shot with the SAECO #315 bullet cast with 30:1 alloy and as you see measures 1.610” with four shots in 1.090” and if I want to eliminate the fliers I will have to do the same thing as Tim. Most shooters would be happy with results like this at 100 or 200 yards but I am not satisfied and I have asked myself the question “What if” and the pursuit for knowledge and perfection continues.

Doc, that is truly astounding shooting.
You have to understand that my pursuit of cast boolits until this year has been completely geared toward the end result of using the most effective means possible to put game animals down. However, since I have leveled my eye's on building the best rifles I am able, with a very serious nod towards shooting cast boolits in every one, my ways of looking at things have changed. I have begun to look past the target spot and see if I can realize some of these results you great fellers have posted about.
That said, I don't know if I could shoot a group that good with jacketed boolits in my 300winmag! Never tried it.
Bear with me though, I'll be with ya in a minute! LOL!

The first time I started realizing that the details matter was when you told me the dramatic effect anealing the gas checks can sometimes have on a group. I tucked that little tidbit away for future reference, and over the last couple years, I have proven that it can indeed have an effect on accuracy!
Then I started making GC makers for certain members (I don't do that anymore BTW). Not knowing what was required, I just made each one to a specific boolit that each client sent me. I would just make it as gosh awful perfect as I possibly could, because I didn't know what I could get away with or not. Low and behold, reports of improved accuracy were a steady theme with these tools. Interesting. Such a tiny little fly fart of material can make a difference?
"Well duh!" you might say!
So is it any wonder that I am looking for near perfection in my boolits? Is it any wonder that I naturally conclude that small details matter?

And lets just look at that GC. Why would the hardness make a flyin rip as to accuracy in the first place? Would it not be the minute change in wall pressure it puts on the inside of the barrel and the way it marries the rifling?
If that's the case, why wouldn't I pay as much attention to the rest of the projectile?
What about the way it is held by the case mouth? Would that not have an effect on how it engraves the rifling? After all, we know that both lead and brass has a little bit of springback, but it won't have time to return to a consistent shape before it engraves will it? Hmmmmmm
Seems to me that making the boolits all have exactly the same strength, making sure the brass is squeezing it the same way, making sure these things react against eachother in a consistent manner, all would have an equally dramatic effect on boolit performance to a slightly greater or lesser extent.

So many questions. So many answers. Only one truth.

[MBTcustom]

Hello fellers.
I come to you with my hat in my hand. A repentant soul. Fully convinced of the error of my ways.

Ahem.

The Rowell ladle came in the mail today.
I took my dremel tool to it immediately and ground off all the casting marks on the inside of the bowl. However, I did nothing to the spout, except use a file to roll the rim over cleanly. I did nothing to the inside of the spout whatsoever. (Just wanted to make that clear for interested parties.)
I couldn't find anything suitable to make a lead pot out of, so I decided to use my trusty 200lb smelting pot. It took me a while, but I managed to build a perfect 150Lb pot of 50/50 alloy (still no tin, please bear with me).
Attachment 91874
I put the fire to it and got it melted eventually, and I made a special clip to hang my thermometer down inside the pot so that I could see what I was doing. Unfortunately, the hottest I could get that voluminous mass of alloy was 650*. Well, I figured I would give it a go but I really thought I would have a lot of sub 173.3gr errors like my first tests had.
It took me a while to get the hang of it. First, I was dumping too much alloy and flooding two cavities at once, then I was trickling the stream too much, and getting poor base fill out. Finally I started pouring a good healthy stream, but keeping to one cavity at a time, and I started getting good looking boolits. I settled into a rhythm, and started dropping them in my little water container with a rag to cushion the falling boolits.
I really didn't expect much being that I have never used this tool before. It didn't take me long to realize that this was a whole different ball of wax. One thing I noticed right off the bat was that the mold was holding heat soooooo much better than with the bottom pour pot. It was just the shear volume of molten metal that was being dumped over it every time.
Little did I know that I was dropping one of the best bell curves yet! Certainly as good as my best run with the bottom pour pot.
Check this out!
Attachment 91876
Not only were these boolits as or more consistent than my previous endeavors with the Lee 20lb pot, but they were prettier. Absolutely beautiful boolits that took every machining mark of the mold.
I am quite confident that I got the alloy exactly the same as the original, not only because I am one anal SOB, but because the target weight (the boolit weight that makes the point of that graph) was identical to the original alloy I was testing in the BP pot. 173.3gr just like before.

Now, I was doing a lot of things wrong. I was not paying attention to mold angle, and I was talking to geargnasher while I was pouring the first of these boolits. I was not watching a clock, or taking anywhere near as much care as I did with the BP pot.
The shocking question is: What if I did? How perfect could I get these boolits if I paid attention to cadence as perfectly as I was doing before?
That is a question that I need to answer.

[leftiye]

Thas why you use a mold heater (with a bottom pour - and everythang else)

[MBTcustom]

Thas why you use a mold heater (with a bottom pour - and everythang else)

There was no time to heat the mold though? It was fill, freeze, drop, shut, fill..... There was no ten second wait to set the thing on a heater?
Perhaps I misunderstand how you use this heater?
Also, I might point out that this is a massive brass mold that dwarfs the little 30 caliber cavities in there.
Can you expound a little more on that? Tell me what to do and I'll sure give it a go and see if it makes my graph pointier.

[45 2.1]

i come to you with my hat in my hand. A repentant soul. Fully convinced of the error of my ways. finally.... About time....

i took my dremel tool to it immediately and ground off all the casting marks on the inside of the bowl. However, i did nothing to the spout, except use a file to roll the rim over cleanly. I did nothing to the inside of the spout whatsoever. (just wanted to make that clear for interested parties.) call when you're ready to try. That part is important.

i really didn't expect much being that i have never used this tool before. It didn't take me long to realize that this was a whole different ball of wax. Seeing is believing ehhh?

the shocking question is: What if i did? How perfect could i get these boolits if i paid attention to cadence as perfectly as i was doing before? Get the right size pot and alter the ladle.

btw.... Happy Birthday

[Pb2au]

Good steel,
For an interesting reference;
I would suggest you obtain some commercially cast bullets and interrogate them for weight. And by commercial, I mean those that are produced off of an automatic casting machine.
I think the results you find would be interesting.

[Pb2au]

And btw, very interesting thread so far.
I work for a machine tool company. One of the things I do a lot of is measuring production off of our machines at customer sites. Productivity, quality, and consistency.

[country gent]

Good steel, Thats one of the reasons I brought up the Brooks vented sprue plate, It does several things to help with consistency. !st is that it allows yo to keep the sprue base molten much longer allowing for perfect fill out. 2nd is ti maintains a consistent sprue on the mold almost every time, once mold is hot and to temp. Until then it kind of like any cold mold it just builds up on the top. Another thing with the Mass of metal in that big pot temp flucuations and mix remained much more even. I routinly cast with a weed burner and dutch oven 100-150 lbs at start. I perfer this as my lee pots are much more fussy. With the weed brurner ( propane) I can have a pot to temp in 1/2 hour or so. The rowel ladle is putting lead into the mold much faster than the bottom pour probably also. I very seldom pressure cast with the ladle but do pour a full ladle into over the vented plate everytime. I use an rcbs mold thats been cleanened up on the outside and the spout opened up to .200. I cast bullets mainly from 400 grns to 560 grns so maintaining that faster fill rate gets tricky otherwise. That big brass molds heat holding capacity and the big ladle will definitly help with consistency.

[Wayne Smith]

I was recently surprised by some of my casting results. I ladle cast with a Lyman ladle and, admittedly, I am not terribly good at keeping my heat constant as the level of lead goes down. I cast some 311291 out of a single cavity mold. When trying to shoot them in my 03A3 I found that maybe 5% of them were too large to chamber. In over ten years of casting this is the first time I have had this happen unexpectedly. I usually know when I have something wrong with the mold and it's casting large. It usually shows up clearly in sizing. This time it is a variance in nose diameter without an obvious variance in body diameter, and no, I haven't measured any.

Guess I need to go back and start weighing rifle boolits again.

[Doc Highwall]

One thing that has not been mentioned is the pressure that one keeps on the mould handles and how it can vary bullet diameter and weight. In Wayne Smiths case he most likely held the mould handles with a loose grip on some of his pours making the bullet larger all over but because the sizing die does not size the nose of the bullet it remained oversize after being lubed.

A member Gussy here makes a real nice pair of locking mould handles that will cure that by giving the same closing pressure throughout the casting sessions.
I believe you will find them under Casting tree the same as the hardness checker.

[45 2.1]

A member Gussy here makes a real nice pair of locking mould handles that will cure that by giving the same closing pressure throughout the casting sessions.
I believe you will find them under Casting tree the same as the hardness checker.

+1... another plug for some of Gussy's excellent products.

[MBTcustom]

quit tempting me to spend money!!
LOL!!

[357maximum]

Keep at it Tim...you are on the right track now..........pretty soon your "bell curve" will look almost like a SaturnV rocket.

One thing that really helps me is to "pre spill" a little stream of lead on the way to the mould.....I.E...I start pouring right before I get to the mould itself, then slowly make the jump to the cavities.

Keeping a notecard for each of your moulds helps too, as they all have their own "personality" and "likes"/"dislikes" . Some will want a slow trickle, some will want a swirling toilet like approach and others will want a Biblical Flood...they are all different.

[MBTcustom]

Got it Gollum. I'm on it like stink on roadkill.
Actually, i was already priming the spout on the ladle. Im afraid that's going to be a pretty common thing for me from now on, after seeing the effect it had on the BP pot. It just makes sense on so many levels.

[357maximum]

Got it Gollum. I'm on it like stink on roadkill.
.

I do believe you are correct....major improvement with the new tools shows that.

When you wanna truly test yourself ...break out the longest skinniest Loverin you can lay your hands on and see.


Have fun,
Mike

[popper]

I will repeat what many casters say, mould/sprue temp not melt temp is the criterion. Obviously venting is very important to eliminate any trapped air. Proper cavity fill rate, cooling rate & venting should eliminate problems. We use cadence to control some of these variables. A comment on your boolit with the bubble, it would be a very small trapped bubble that expands and creates the large void, don't see how you could trap that much air in a boolit. It wouldn't even need to be air but any trappable, expandable material caught in the pour - dust, oil, oxidized material that gives up O2 when cooling, etc. I will still maintain (maybe wrongly) that most weight variation is due to poor fill out and probably will not have much effect on accuracy - as long as it is symmetrical, i.e. improper filled lube groove.

[MBTcustom]

I do believe you are correct....major improvement with the new tools shows that.

When you wanna truly test yourself ...break out the longest skinniest Loverin you can lay your hands on and see.


Have fun,
Mike

Alright I just have to say it: "your avatar creeps me out!" There. I said it, and I feel better now.

Ahem.
I have heard stories about a mold called the "cruise missile" being one of the most challenging boolits ever devised to get a perfect boolit from. Think I'll stick to easier things for the moment. LOL!
My buddy across town has a heavy boolit mold for the 300blk that drops a loooooong boolit. Those had a problem where they were actually warped! They looked like a bunch of silver bananas laying in the bowl.
Definitely not the easiest to get good results from.

[geargnasher]

The Cruise Missile ain't nuthin' but a thang......



Bottom-poured from a Lee pot and water-quenched. They come out just peachy IF you are absolutely ruthless about pour technique, timing, and temperature. They actually bend when peeling out of the cavities if your mould isn't in 100% burr-free working order.

Tim, remind me to tell you about "goat-azzes" next time you call. Best way I've found to tell that you're cutting the sprues at exactly the same time in the cooling cycle time every time.

Gear