How consistent are you REALY???

[cbrick]

I don't think a PID helps as much as consistent timing, rhythm, and pour technique. Rhythm is what dictates mould temp which is, in my opinion, more important than melt temp.

Casting pace (rhythm) is of course important but . . . The most even paced casting rhythm possible would also need to match/change with the changing alloy temp or the mold temp also changes, rather difficult. As the level of melt in the pot with a thermostat control goes down the temp of that alloy goes up.

The PID can and does keep the melt temp even thus making a steady casting rhythm far easier and the mold temp more consistent.

Rick

[geargnasher]

I've been advocating casting thermometers, PID controllers, analog wall clocks with a second hand on the wall behind the casting pot, and a rigid attention to detail of rhthm, temperature, and timing for a very long time. I'm glad the subject has finally been breached in a way that didn't bring an avalanche of naysayers and accusations of "getting wrapped around the axle" or being "pedantic" with regard to going the extra mile to ensure that you are, in fact, casting the best quality boolits that you know how to, and refining your personal skill set and methodology in the same regard.

Hat's off, Tim.

Now, go back and ponder Mike's post on the first page. Bob knows a thing or two about this. I told you his method, and I still think it's the best, at least it was for me. If you do what Mike suggests, you WILL learn a lot about what's really, really important and what's not. I'll give you a hint, variances in distance will change the answer. You can do it with a bottom-pour, even a Lee (I do because of convenience and weather), but as you're finding out it takes a bit of work to get results. There's a reason why a #2 Rowel ladle with the spout bored out and a 75-lb pot of lead heated over an open flame works so well, and you've proved why.

Gear

[MBTcustom]

Goodsteel,

What was your total weight variance? Perhaps we can calculate a standard deviation and see how small we can get that with the techniques you are creating.

Thank you for the info on all this. Ill work on these techniques to become a better caster.

How do the "big boys" compare as far as weight variation goes?

I also vote for sticky status. This is good stuff.

First of all, I'm not "creating" anything. This has all been done before, but I thought some fellers might benefit from seeing it in picture form here on the forum.
Total deviation seems to be about .8 grains based on the last bell curve I posted (I might not understand what you mean).
I have no idea how anybody else does, but I'm quite sure that there are some here who's bell "curve" would be a straight line, one end of the bench to the other.
All I know is that this is an accurate way to measure your consistency. It is scientific and does not lie, as long as you keep your finger off the scale (you have no idea how badly I wanted to throw that 173.7gr boolit back in the pot before taking the picture! LOL!)
Again, this is not about shooting. You might be the best shot in the world, but that doesn't get you very far when you are sitting in front of the pot, because as far as I know, there is no way to mount a creedmoor sight, or a scope to the pot to any advantage. You're not going to impress the fellers at the range with your casting abilities if the paper doesn't tell a good story, and you're not going to impress any casters if you can't cast a consistent string of boolits. We are talking about two separate disciplines.

[geargnasher]

Tim, out of 500 I usually see an ES of about a grain, the ES being accounted for by three or four that looked good out of the mould but either caught a huge air bubble or I didn't get the blocks closed just right. Normally, I end up with two piles within half a grain of each other if casting .30-caliber, more like a grain if casting the big .45s.

Example: I just got through sorting a bunch of AM 31-185Gs that I cast last spring. Average with 50-50 alloy was 183.3 grains. Minimum was 182.8, max was 184.0. Take away half a dozen boolits and the 300-count pile averaged 183.1 to 183.7. I sorted two piles of about equal size from 183.1 to 183.3, the other 183.4 to 183.7. I didn't mark the cavities of this two-holer, but I'd put money on an alignment pin being a few tenths proud.

Now, during a casting session, I tend to cull boolits as I see defects (keeps me entertained for a second or two as the sprue cools), and with a bottom-pour I cull a LOT while casting, maybe 10% or more as a rough estimate, so it ain't that I'm all that good, it's that I pre-cull the worstest ones right on the spot.

Gear

[kenyerian]

This has been a great thread. I do weigh my bullets for my hunting loads . Any thing that gives me consistant results saves me time. My Hat's off to Tim for scientifically recording his results and sharing them.

[35 shooter]

Just read thru this thread and enjoyed it. Picked up some things to try next casting session. I've been trying to improve my techniques also but about the best i seem to do is is plus or minus 1 grain then i usually sit up all the next night weighing everything plus or minus 1/2 grain. What i don't understand are seemingly intentional jabs at a guy just running an experiment trying to hopefully find a way to shoot cast boolits with more precision. Benchrest shooters have been doing that for ages by trying to stick all their shots in 1 hole in the target. Their efforts and posted results have over the years virtually revolutionized the whole shooting industry from reloading dies, presses, to an effort to make more precision factory rifles, powder, and everything in between. We've all benefited from those efforts and experimenting whether we realized it or not. I personally see goodsteal as a guy that knows a lot about his preferred hobby as we all do if we've been at it long enough but also for every answer he finds, two more questions pop up. I've always thought that was a good thing? Inquiring minds just gotta know!

Will bettering my casting technique improve my groups? Probably not in and of itself. But that in combination with neck turning, reaming, neck sizing, measuring boolit length from the ogive for precise seating depth and a host of other things together might just get me from 1.5" to 1/2" groups. Okay sorry, just didn't understand some of the comments. Good thread goodsteal!

[Newtire]

Great work! I don't think I'll ever be able to have the patience to do anything close to this. I have weight segregated boolits before out of a one holer and then weight segregated cases that were cleaned in citrus cleaner inside and out and trimmed to the same length and gotten some pretty good results. "The name of the game is the same". Now how come I get that flyer that screws up my group-I think it's the guy at the primer factory getting that extra little smidge of compound into that one primer...? Maybe that extra piece of bacon I ate that morning?

[milkman]

If you check boolit diameter with a mic., boolits with a great deal of weight difference will also show diameter difference. Melt, mold, casting rate... consistency matters.

[Jim Flinchbaugh]

If you check boolit diameter with a mic., boolits with a great deal of weight difference will also show diameter difference. Melt, mold, casting rate... consistency matters.

Woohoo, I'm a bit ahead of goodsteel on something
I forgot I did this almost a year ago
http://castboolits.gunloads.com/show...=sorting+board

[osteodoc08]

I'm all for scientific endeavors and applaud you guys, however, I just don't see 1-2 grains as a huge variation in the grand scheme of things considering the type of shooting I do. That said, all my hunting boolits I weight and only keep the ones within a 0.5gr window. The rest get culled.

I challenge you guys to bench the gun at a given distance of your choosing and see if there is any change in accuracy from your lightest boolits, target weight boolits and your heaviest boolits.

[Doc Highwall]

Jim, I really like that board with the slots to keep the bullets seperated I am going to make one for myself.
I have done this my self using masking tape on the kitchen counter and the board looks much better.

[prs]

Can I reverse that order? LOL!


OK, first of all, even if it doesn't make any difference down range, I consider casting and shooting to be two separate disciplines loosely connected at the hip. A person can be quite good at one and suck muddy rocks at the other.
That said, the only factors we have to judge our proficiency at the pot are:
Alloy
Weight
Appearance
Hardness/malleability
And ultimately, downrange accuracy.

The alloy is determined up front, or by laser XRF if you're lucky and really becomes the rose colored glasses through which you view each batch of boolits. The hardness can be tested but usually damages the boolit in some way (neither here nor there, smoke if ya got em). Obviously, shooting them is kind of final, no do-overs, no erasies, and you have rather decided to change sports there.
All that's left is weight and appearance.
All I did, was observe that the boolits produce a graph of proficiency if you will, and help you to see what is working for a particular mold.
I'm a bit of an accuracy junky anyway. I really really care about the things I make being superbly accurate, and it always bugged me that I couldn't see the subtle effect a certain change in procedure would have on my casting.
Neither here nor there.
All I am saying is that if you want to know how accurate you are with your particular casting technique, mold, alloy, cadence, and mental constitution, you can visually measure that by ordering them by weight on a piece of paper.
It does take some time, but the effect is fascinating!
Last night I had to try it again.
In this test, I ran the pot back at 700*, preheated the mold, threw out the first eight drops, and ran the spout for two full seconds before sweeping the mold under the stream and filling it.
The results were dramatic!
Attachment 91283
I still have some variances, but I'm almost certain that came from the times I put the built up lead in the ladle back into the pot. This cooled the melt, which in turn made the mold run slightly cooler. I wish I could afford a 40lb magma pot, but that just isn't in the cards right now.
But dang! I'm scaring the hell out of it with my Lee 20 pounder eh? LOL!

Now you'r talk'n!

prs

[felix]

I challenge you guys to bench the gun at a given distance of your choosing and see if there is any change in accuracy from your lightest boolits, target weight boolits and your heaviest boolits.

Yes, the 222 bench gun on-hand can tell the difference in only ONE TENTH GRAIN difference at 50 yards. Keep in mind, though, a CAST boolit is not a SWAGED BOOLIT. The former has hidden air holes which DO without doubt throw booits randomly when compared to the latter. ... felix

[prs]

I don't open the gate 2 seconds before the pour, but most of one second. Most sprue plates have enough room at the heel end to accept that initial "cold" ejecta from the spout. That helps. I find new molds to be inconsistent regardless of prep effort. As they age to be old buddies, the result is improved consistency.

prs

[Pat I.]

Yes, the 222 bench gun on-hand can tell the difference in only ONE TENTH GRAIN difference at 50 yards..... felix

Really? What kind of groups are you getting at 50 yards that you can see a one tenth grain difference in bullet weight on the target? Inquiring minds NEED to know.

[BruceB]

The former has hidden air holes which DO without doubt throw boolits randomly when compared to the latter. ... felix

I would amend felix's statement to add the word "may"...... the cast bullet MAY have hidden air holes....

This one-tenth-grain variation showing up in groups with .22-caliber rifles also MAY be the reason that we see large calibers, over the long run, being easier to work up to good accuracy. Such minor variances have more effect on lighter bullets than heavy ones.

I don't weigh cast bullets, as a general thing. The shooting I do simply doesn't require such intense concentration on minutiae. Not that there's anything wrong with such detail work; I enjoy reading about the experimentation, and the results from it are often educational.

I found out THROUGH WEIGHING MANY LARGE BATCHES, that my visual inspection detects more flaws than does weighing. I attribute this to my casting method, which uses very high heat, which (I think) minimizes the possibility of internal voids in the bullets.

For example, I once weighed every bullet in a run of over 800 from an RCBS 2-cavity mould for the 416-350 design. The MAXIMUM SPREAD was less than one grain in bullets averaging around the 365-grain mark. Visual inspection rejected just three bullets out of 800-plus. They were cast from COWW at 870 degrees, and my Ruger #1 rifle will group TEN of them inside one inch at 100 yards....departing at 2050 fps.

Similarly, a Model 70 in .338 has grouped ten 220-grain cast bullets (LEES!) inside the magic inch at the same range.

With any luck, I hope to embark on a campaign this coming year with my first .22-caliber cast bullets. I will be using my current casting methods at the outset, but I'll be VERY curious to see if I have to go to the lengths reported in this thread. I may be an old dog, but y'all know that the old saying about 'new tricks' just doesn't hold water....at least, not for us bullet-casters!

[waksupi]

Really? What kind of groups are you getting at 50 yards that you can see a one tenth grain difference in bullet weight on the target? Inquiring minds NEED to know.

That comes in when you start playing the serious bench rest game.

[MBTcustom]

That comes in when you start playing the serious bench rest game.

Which, incidentally, Felix has. More than most.
Just sayin.
If Felix says he can see 1/10th, then he can.

[Pat I.]

That comes in when you start playing the serious bench rest game.

What exactly is "the serious bench rest game"? Are you saying that jacketed bullets are "serious" and cast bullets aren't? Are you suggesting that someone would test a heavy or light varmint class "serious" rifle at 50 yards either in a warehouse or outside? If you think cast bullet benchrest isn't as serious as any discipline out there my suggestion is you build yourself a rifle and come out to a match.

[HARRYMPOPE]

I agree-
When you go to cast bullet matches and Stolle's,Halls and Nesika Acions are on the line its serious! Thats what it takes to win Heavy or UNR class these days.You are not going to take a Mauser 98 put on a fat barrel and win a thing.Those days were 30 years ago when it was not so serious.