Wide variance casting weight

[MOshooter]

I am trying to figure out and lessen the weight variance I am getting casting with a Lyman 20 mag bottom pourer and a Lyman 215 grain semi wadcutter using the four cavity mold

I am using this boolit in a scoped S&W 629 44mag so I am looking for accuracy and consistency for a 100 yards.So far my boolits are varying a very wide range from the 215 grain mold,the weight variations are from 206-211 grains with the majority of the bollits weighing in the 208-210 weight range.

I have several questions about this
1 How can I get a more consistent weight from my pours?
2 How large of weight variance is acceptable as a rule of thumb? Say shooting out to 100 yards?

Thanks

[mooman76]

The more you cast, the more consistant you will get. Try to keep everything the same. You my try separating your different cavity boolits to make sure or see what if any differance there are between cavities. Check for mould alignment each time you cast. If your mould isn't closed by a hair, it could throw you off a couple grains. Also when I have longer casting sessions I tend to p/u little tiny pieces of lead between the mould halves which also adds to the weight. You might have to just cast allot of boolits and separate them by different weights. Each individual have their own eight toleances according to their needs. Remember for you boolits on a 200gr mould 2gr. is only 1% differance.

[onondaga]

That weight variance is about normal. If your general loading methods are excellent and you have found the accuracy sweet spot for your load you should be able to group 1" at 50 yards without weight matched boolits.

The .44 is not the only caliber sensitive to LOA, chamber fit, boolit fit to barrel , seating tension, cartridge case length, weight, wall thickness, primer pocket uniformity, and powder charge ignition and weight and crimp consistency so much more so than boolit weight. In fact if you gain NO accuracy when changing to use weight matched boolits this is a sure sign that you really have arrived at the sweetspot of accuracy for your firearm and the sweetspot is broad enough that matched bullets make no difference at all. A really balanced sweetspot will even tolerate a surprising swing in charge weight along with bullet weight swing and still group an inch at 50 yards.

If those things have been dialed in to perfection you will gain very little to nothing by matching boolits, but here are some suggestions:

1) Maintain pot temp 100 degrees over fluid temp of your alloy.

2) Maintain mold temp 100 degrees under fluid temp of your alloy with casting cadence.

3) Only add sprues and ingots when you begin a new melt so your pot temp doesn't drop during a casting session.

4) Keep your nozzle stream length short and consistent at 1/4 to 1/2 inch.

5) Keep your sprue puddle size the same size.

6) Keep sprue plate tension the same.

7) Keep hand squeeze on your mold handles firm and constant.

8) Inspect mold faces for splatter that swings bullet weight by opening mold.

9) Cast consistently with sufficient temp controls of your alloy and mold that your fill-out of mold is consistently the same under magnification.

10 When cutting your sprues , cut at the same moment of solidus consistently so you don't have some sprues chunk out and some cut smooth and flat.

11) Get real good at evaluating and controlling your fill-out with the important temp controls of mold and pot or get a good thermometer and use a watch to time sprue solidification as a monitor of your casting cadence to solidify sprues at 4-6 seconds.

12) Only flux and skim the pot once at the beginning of a session melt. Cover melt with sawdust and keep casting till your pot has 1 inch left. Your metal is pouring from the bottom so don't fuss with the top of the melt or add sprues, just cast and later check your boolits only when the next melt is cooking or you are done.

Gary

[MOshooter]

mooman Thanks for the advice.
I did weigh each boolit with the most boolits in the 208-210 weight range,I think the rest will go back in the pot 206,207,and a few 211's
Casting the Boolits look great I keep my pot at 725-750 degrees.Seems my mold stars heating up fairly quick when my boolits start hanging in the mold,I may be casting too fast? and probably need a more consistent method in cooling my mold back down to a more acceptable temp with the same consistent rhythm.

Thanks again

[MOshooter]

Gary Thank you
I really appreciate the in depth outline for consistently poured boolits. I see a few that I need to work on #5 and quit doing #3 :mrgreen:
I also haven't been doing #12 covering my melt with saw dust? I have been fluxing every 20 minutes instead of once.

Thanks again for the advice

[stubert]

I would keep them all with the variance your'e getting. 1% is fine.

[Frank]

Great info here. Electronic scale makes it very easy to sort. If they're weight different then sort them and put them in baggies.

[MOshooter]

I would keep them all with the variance your'e getting. 1% is fine.

Thanks Stubert,if I keep the 208-210 grain? wouldn't those be within 1%?...Now if I keep all the 206-211's I will have a 5 grain weight differential which is about 2 1/2% variance?


Great info here. Electronic scale makes it very easy to sort. If they're weight different then sort them and put them in baggies.

I agree a lot of great information and I really appreciate all the knowledge and input.I thought about saving a grouping different weight boolits,I may save them and see what my next batch is weighing.
Those electronic scales sure are nice and make life easier :mrgreen:

[williamwaco]

onondaga +1

Your variance is quite good for a bottom pour. I only know two ways to improve on it and you are not going to like either one of them.

With handgun bullets and a long bottom pour session - say 1000 bullets I get about a 6 grain range with 95% of the bullets in a 2 grain range.

I first learned that if I want really consistent weights, I need to use the ladle. when using a ladle on a nominal 247 grain bullet, My weight varies from about 243.7 to 245.5.

Since you didn't buy a 20 pound pot to ladle pour bullets, I find the pot can almost equal the ladle if you maintain a fairly constant lead level of no more than two inches in the pot.

You will notice the lead comes out much slower and with much less force. Using this method, you can get more consistent weights.

After all that bad news, the good news is forget it!

With handgun bullets of that weight you will not notice any difference in accuracy unless you are shooting them in a scoped rifle, and even then I doubt you would notice it. ( I do not know anyone who has actually tried it. )

[cbrick]

Another thing you can try, usually the first pours of a casting session will be the lightest bullets. If your pre-heating your mold this should be only the first few pours. If your not pre-heating the mold it could be as many as 12-15 pours before the mold is at a consistent temp.

Also, I haven't seen an electric pot yet with the exception of PID controlled pots that won't get considerably hotter as the level of alloy goes down. I only cast until the pot is about half full, then add the sprues, rejects & more alloy with the mold on the hot plate.

Rick

[MOshooter]

onondaga +1

Your variance is quite good for a bottom pour. I only know two ways to improve on it and you are not going to like either one of them.

With handgun bullets and a long bottom pour session - say 1000 bullets I get about a 6 grain range with 95% of the bullets in a 2 grain range.

I first learned that if I want really consistent weights, I need to use the ladle. when using a ladle on a nominal 247 grain bullet, My weight varies from about 243.7 to 245.5.

Since you didn't buy a 20 pound pot to ladle pour bullets, I find the pot can almost equal the ladle if you maintain a fairly constant lead level of no more than two inches in the pot.

You will notice the lead comes out much slower and with much less force. Using this method, you can get more consistent weights.

After all that bad news, the good news is forget it!

With handgun bullets of that weight you will not notice any difference in accuracy unless you are shooting them in a scoped rifle, and even then I doubt you would notice it. ( I do not know anyone who has actually tried it. )

Thanks William I thought 6 grains off was a large margin??? I also really appreciate all the casting advise,I may have to try out a ladle with those consistent numbers you're casting very impressive!


Another thing you can try, usually the first pours of a casting session will be the lightest bullets. If your pre-heating your mold this should be only the first few pours. If your not pre-heating the mold it could be as many as 12-15 pours before the mold is at a consistent temp.

Also, I haven't seen an electric pot yet with the exception of PID controlled pots that won't get considerably hotter as the level of alloy goes down. I only cast until the pot is about half full, then add the sprues, rejects & more alloy with the mold on the hot plate.

Rick

Rick Thanks for the advise

[noylj]

Is it just me or is the O.P. complaining about the natural order of things and worrying about weight variations that are more than just typical?
The weight range is in my normal range and I tried sorting by weight years ago and found that it had NO benefit out to 50 yards in my .45 Auto and no statistical benefit at 100 yards in .44Mag through my T/C Contender.
It did seem that the heaviest bullets (the ones that I assumed had the least voids) were the most inaccurate and the light ones (that I assumed had the largest voids) grouped right with the average weight bullets.
Also, intentionally making sets of rounds that represented a true mix of weights still grouped right with the grouped averages (except for the 3-5 heaviest outlier bullet).

[MOshooter]

Is it just me or is the O.P. complaining about the natural order of things and worrying about weight variations that are more than just typical?
The weight range is in my normal range and I tried sorting by weight years ago and found that it had NO benefit out to 50 yards in my .45 Auto and no statistical benefit at 100 yards in .44Mag through my T/C Contender.
It did seem that the heaviest bullets (the ones that I assumed had the least voids) were the most inaccurate and the light ones (that I assumed had the largest voids) grouped right with the average weight bullets.
Also, intentionally making sets of rounds that represented a true mix of weights still grouped right with the grouped averages (except for the 3-5 heaviest outlier bullet).

Me being the OP I am not complaining,just trying to figure out what is an acceptable weight variance and how I can improve and uniform my casting skills definitely not complaining??????

[noylj]

Very good. It just sounded like the typical newbie who expects perfection and spends more time trying to solve problems he probably doesn't have then he does shooting and seeing if his concern actually means anything.
Most people from my generation never expect perfection and worked with what they had and, slowly, worked out what variables actually affected the target and gun.
They started off casting and shooting and looking at targets to see if there was a "problem," rather than starting off looking for problems.
I know when I started casting, I was just happy to have some nice looking bullets and worried about "details" like weight variation after I had been casting for a while and had decided to try and "improve" things--and I knew this was much better than buying bullets. Weight variation came after barrel leading, alloy, temperatures, lubricants, and load development.
Also, just so you know, if you cast some bullets that are not very pretty (say, have a wrinkle or two like I do) but the base and first driving band are well-filled out, they will group just like the pretty bullets out to 25-35 yards and, often, longer range.
I guess what I am trying to say is that I want the newbie to have thrill of success rather than immediately looking for problems. If all you see are problems, you are not going to be a caster of boolits for very long

[MOshooter]

Very good. It just sounded like the typical newbie who expects perfection and spends more time trying to solve problems he probably doesn't have then he does shooting and seeing if his concern actually means anything.
Most people from my generation never expect perfection and worked with what they had and, slowly, worked out what variables actually affected the target and gun.
They started off casting and shooting and looking at targets to see if there was a "problem," rather than starting off looking for problems.
I know when I started casting, I was just happy to have some nice looking bullets and worried about "details" like weight variation after I had been casting for a while and had decided to try and "improve" things--and I knew this was much better than buying bullets. Weight variation came after barrel leading, alloy, temperatures, lubricants, and load development.
Also, just so you know, if you cast some bullets that are not very pretty (say, have a wrinkle or two like I do) but the base and first driving band are well-filled out, they will group just like the pretty bullets out to 25-35 yards and, often, longer range.
I guess what I am trying to say is that I want the newbie to have thrill of success rather than immediately looking for problems. If all you see are problems, you are not going to be a caster of boolits for very long

WOW I didn't know you knew so much about me??? lol, and how off course one can get from the original post and question????
I go from a complainer to a newbie in just 2 of your post is that called pessimistic or what???? ROTF...

FWIW I have been shooting and hunting over 42 years and grew up in a reloading room with bird dogs in the backyard.And yes I am a bit of a perfectionist that's why Whitetails drop 5 football fields away and why I have been in business for 21 years...Now you know a little bit about me.