Analysis of cast boolit weight variences

[rbertalotto]

I was reading the Lyman's Cast Bullet Handbook, 4th edition. One of the authors talks about only keeping bullets that fall within .6 grams of each other. Six Tenths of a grain. I was surprised at that number so I went to the "lab" and did some weighing.

I used the same technic as spelled out in the handbook of making a visual chart to log the various weights.

First up are some lubed bullets cast from Wheel Weights.......

http://images109.fotki.com/v779/photos/2/36012/9869255/P1020711-vi.jpg

The next group was from "manufactured" bullets that I had bought before I started casting myself.....

http://images110.fotki.com/v629/photos/2/36012/9869255/P1020712-vi.jpg

And another series of "manufactured" bullets....

http://images9.fotki.com/v114/photos/2/36012/9869255/P1020714-vi.jpg

This group is from bullets I cast yesterday. Not lubed yet.....

http://images55.fotki.com/v608/photos/2/36012/9869255/P1020720-vi.jpg

And finally a very surprising outcome. What's up with those Bad Boy bullets????

http://images109.fotki.com/v779/photos/2/36012/9869255/P1020725-vi.jpg

Comments? Anyone else ever weigh their boolits and see how consistant they are?

I'm going to keep accurate records as I shoot these boolits to see how this affects accuracy.........

[303Guy]

Interesting results - and layout.

Funny how there seems to be weight groupings like that. I've found that there will be gaps in the weight range too. Mold or alloy temp doing it? I bought myself a scale that has a 0.01g resolution for NZ$18 (less than US$). It's faster and more accurate than my NZ$100 one!

[John Boy]

Anyone else ever weigh their boolits and see how consistant they are?
Only for bullets that I shoot for BPCR and Schuetzen - long range, 200m to 1000yds in the 165 to 570gr range. My 45 Colt ones - don't really care but usually they are with 2 gr variances
I see that each of your bullet batches have a bell curve. This is normal but the variances can be tightened with several casting techniques:
* Only drop poured bullets when the pot/mold temperature produces a sprue puddle that frosts at 5 - 8 seconds.
* Then hold that temperature consistent for the whole casting session
* Pour your lead: tilt mold to the right or left - put the ladle spout firmly into the sprue hole - turn the mold vertical - keep a good head pressure for a 5 second pour with the spout still firmly in the sprue hole. Your bell curve will tighten up if you maintain the same smooth consistent rhythm

I cast for 0.5gr bullet variance and weigh each one. Those outside the curve I use for practice.

[DrB]

Neat plots!

How many cavities is each mold? Can you annotate your original post for each plot of weight's for your molds with the number of cavities?

I'd bet the multimodal plots are from the different cavities... Though it could also be temperature related I suppose. So I'm wondering if there are multiple cavities for each plot with multiple modes. If you have two modes from two cavities that can give you three peaks in the distribution from the overlap of the tails.

That could be making too much of this though as your sample size is relatively small from the standpoint of resolving a distribution. To get the tails pretty well and get a fairly smooth distribution curve you might do several thousand samples (!). 10,000 is the number we'd usually use in numerical studies, but that's clearly off the deep end for what you are doing.

You might cast three or four more noting the cavity and plot them to see if they consistently fall into one of the humps of your plots.

[rbertalotto]

First mold is Two Cavity. Not sure what the "manufacturers" are using. The two Lyman molds are single cavity.

My furnace (melting pot) uses a PID to control temperature within 15 degrees. I'm running my allot at 725 degrees.

My molds have a hole drilled and a temperature probe attached. Mold are held to 350 degrees +/- 10 degrees.

My three rifles that use these bullets (1895 Marlin, Winchjester 1885 and Pedersoli 1874 Sharps) all 45-70, all shoot under 3" at 200 yards. The Marlin has irom sights, the other two have Leatherwood Malcolm type scopes of 6X.

I just find it interesting that there could be this type of varience, especially those Postells with a bunch of "Bad Boys".....We're talking nearly 10 grains over the average. I didn't even think this was possible.

The reality of all this is, if you don't weigh and sort your bullets, you are going to have all kinds of fliers I suspect.

[waksupi]

If you get some of Gussy's handles, you can cut this variation considerably.

[Doc Highwall]

I will second the handles from Gussy.

[leadman]

The bad boys might be larger in diameter. Sometimes a speck of lead will keep the mold open just a touch.

[1Shirt]

Much of weight variance is due to casting technique, speed of casting, consistancy on the part of the castor, etc. Any variance of timing, can be a difference in weight. For handgun, I am satisfied with 1/2 to 1 grain difference, as I am not a match shooter. For rifle in large cals above 30, am satisfied with 1/2 grain variance. For small cals 22-6mm, I want exact weights and seperate them accordingly on the basis of bell shaped curve. The ones on either end of the curve go back in the pot- or in the cull box to be used only for plinking. Good thread!
1Shirt!:coffee:

[John Boy]

For folks that weigh by 0.5gr increments, here's an easy way to make a 'Bullet Board' for the measurements:
* Put a long piece of masking tape on your work bench
* Mark it in 1/2 gr increments:
0 - .5 - 1 - .5 - 2 - .5 .... out to 9.5
Lay the bullets under the specific increment. Then you can double or triple stack them depending on how many you cast by standing a couple bullets at both ends of the stack to keep them from rolling around

[rbertalotto]

OK, I give up!

Gussy's handles????????????

[DrB]

Fellow named jim gussy of cabintree sells locking mold handles that are supposed to tighten up roundness/weight of boolits by ensuring more consistent pressure on mold halves.

I've never used them or heard of 'em... I had to look 'em up in case one of these old guys was sending us after some "shore line." :)

I take it they help...

Thanks again for posting your plots... Interesting results, especially given how much you are doing to control lead and mold temps. If you happen to experiment with your technique and repeat your plots, please share them. Would be great to know what ends up working or not for you.

[Doc Highwall]

The handles have a over cam feature that give the exact same closing pressure each time the mould is closed. If you have a high gripping pressure when you start casting and as your hand gets tired the lighter gripping pressure will make bullets that are heavier. For the best match bullets these mould handles have no peer.

[reloader28]

I've never weighed pistol boolits.
I weigh all my rifle boolits and keep them within a .5 grain.
My .223 cal boolits are usually kept within .2-.3 grain.

I used to get 2 grains difference in my 150gr RCBS 30 cal 2 cav mold until I figured out the cavities were a tad different. I beagled one side out and that cut it back to only 1 grain difference.

I made some Lyman 173gr FN 30 cal single cav one night with 50/50/2% alloy and in 200 boolits, I threw back only about 9 or 10. The rest were all within .3 grain.:grin:

The planets were all aligned perfect that night.8-):drinks:

[geargnasher]

I've done that too, but it's been a while. Doing it several times isn't the most fun I can ever remember having, so thanks for posting your work.

Gear

[noylj]

Each cavity will cast a little different, and I expect commercial casters use two-cavity molds when they can.
I don't know what current knowledge is, but I always felt that if I didn't flux frequently, my alloy would shift.
I have found that, for pistols, the extreme light and extreme heavy bullets tend to shoot just all well as the bullets in the peak(s) in the bell curve(s).
Since these appear to be for a rifle, you might want to segregate by weight and see how each set of bullets groups in terms of group size and location on the target. This will tell if there is any "thing" to correct.
I know that I felt that the light bullets MUST have voids and would be inaccurate, while the very heavy bullets must have the least voids since there are no impurities heavier than lead that should be in my alloy. However, with my pistols, I never saw any difference.

[Bret4207]

Grams or grains? 1 gram is 15.4 grains.

[rbertalotto]

GRAINS!!!!!!!!!!! Sorry, I corrected the OP

[HollowPoint]

I did a similar test back when I first started casting and I got results that resemble yours.

Because I was new to casting I really had no idea why there would be such a variance in weight.

I'm still not totally convinced that any individual reason sighted here is directly to blame with these different weights from the same batch of cast bullets. I suppose it's a combination of various contributing factors.

Now days if I'm looking for Load-Work-Up precision, I sort them by weight.

The only difference for me is that I can live with cast bullets that fall within 2 to 2.5 grains difference. This is for my rifle bullets. Pistol bullets generally don't get this kind of weight sorting.

Why 2 to 2.5 grains you may ask? Well, when I work up loads for my rifles, I use the "OCW" method. My charge weights are done in .3 grain increments with any given cast bullet. These cast rifle bullets fall within 2.5 grains because I've weight sorted them.

I don't know if this makes any sense at all to anyone else but me. I'm not trying to come across like my rationale is right or wrong compared to anyone else. It's just the way I work up my loads. It always seems to work out well for me given enough time and testing.

("OCW" = Optimum Charge Weight.)

HollowPoint

[6.5 mike]

Thanks for the info on Gussy's handles, I've look at them on his site thinking they would help me. I do weigh all my boolits when first using a new mould. What I do if it's a 2 cav, is mark one (usually the front) with a marker so I know which one came from which cav. After they cool I take them in the house to weigh & measure, use an elec scale & mic. SWMBO says I get to play with my toys longer this way, lol. The pistol boolits are just to see if the specs are close to as what it should be, & the rifle are checked closer. I do 10 of each, check 5 that day, & do the other 5 when I get back off the boat. This gives the 2nd batch 2 to 3 weeks to age.
I got a rcbs 7 mm 145 sil from a member here a while back that drops so close together if I hadn't marked them I would not have been able to tell which cav was which. Brp & Noe moulds are the only others that do the same for me.

[rbertalotto]

More on the subject with range testing.........

I loaded up a bunch of Lyman 457-132 Postell boolits that my Pedersoli 1874 Sharps shoots extremely well.

Using a 6X Leatherwood Malcolm scope at a range of 200 yds, here are the results that various weights have on accuracy. Totally unscientific as there simply aren't enough shots fired for a real statistical analysis. But interesting none the less.....

Bullet Weight Test #1, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 525.3 - 525.9 bullet weight
http://images110.fotki.com/v630/photos/2/36012/9730091/0704111119-vi.jpg

Bullet Weight Test #2, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 526.4 - 526.8 bullet weight
http://images53.fotki.com/v52/photos/2/36012/9730091/0704111119a-vi.jpg

Bullet Weight Test #3, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 527.3 - 527.8 bullet weight
http://images29.fotki.com/v1017/photos/2/36012/9730091/0704111119b-vi.jpg
BTW, that is two boolits into the hole at 9 o'clock....

Bullet Weight Test #4, 5 shots, 200 yds, 24g SR4759, .010" away from lands, Random Weights 521.3 - 535.6 bullet weight
http://images35.fotki.com/v1132/photos/2/36012/9730091/0704111120-vi.jpg

All were shot over a Ohler 35 chronograph.....

The ave velocity of the 15 weight sorted boolits was...1206 FPS
Extreme spread of 41 FPS, SD of 14.......

The ave velocity of the RANDOM weight boolits was...1221 FPS
Extreme Spread of 42 FPS, SD of 15

Comments on any of this????

[rbertalotto]

OK, once again the fine folks over here on CB got me thinking........Thinking about contact pressure of the mold handles that is. So I decided to figure out a way to keep this constant.

Gussy makes a great set of "Constant Pressure handles", but I'm inpatient and want to do some casting tonight.

So I built these:

http://images33.fotki.com/v1074/photos/2/36012/9874505/0704111648-vi.jpg

And I wrote a whole "How To" article on my web site if you want to make a set for yourself......Didn't take me an hour, beginning to end.

www.rvbprecision.com

Now I have to try them out and see if they improve things around here!

http://images53.fotki.com/v536/photos/2/36012/9874505/0704111647-vi.jpg

[DrB]

More on the subject with range testing.........

I loaded up a bunch of Lyman 457-132 Postell boolits that my Pedersoli 1874 Sharps shoots extremely well.

Using a 6X Leatherwood Malcolm scope at a range of 200 yds, here are the results that various weights have on accuracy. Totally unscientific as there simply aren't enough shots fired for a real statistical analysis. But interesting none the less.....

Bullet Weight Test #1, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 525.3 - 525.9 bullet weight

Bullet Weight Test #2, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 526.4 - 526.8 bullet weight


Bullet Weight Test #3, 5 shots, 200 yds, 24g SR4759, .010" away from lands, 527.3 - 527.8 bullet weight

BTW, that is two boolits into the hole at 9 o'clock....

Bullet Weight Test #4, 5 shots, 200 yds, 24g SR4759, .010" away from lands, Random Weights 521.3 - 535.6 bullet weight


All were shot over a Ohler 35 chronograph.....

The ave velocity of the 15 weight sorted boolits was...1206 FPS
Extreme spread of 41 FPS, SD of 14.......

The ave velocity of the RANDOM weight boolits was...1221 FPS
Extreme Spread of 42 FPS, SD of 15

Comments on any of this????

Actually, this is PLENTY of data points for a potentially interesting regression analysis, but I'm not sure you can make anything from it as you've done it.

This reminds me of something that's bothered me before in my own testing. Really, the order of the different weight "settings" should be randomized (don't do all of a weight range at once), and/or sequential so you can separate thermal, fouling, wind convection, and maybe other effects from the effect of weight, don't you think? If the weight settings are more evenly distributed over time then cumulative and time dependent effects are more easily averaged out to determine the effect of just your weight parameter...

Also, my supposition would be the primary differences between the different weights of bullets would be related to internal and not external ballistics, and so I would be tempted to reduce your range for the shots down greatly to reduce any impact of wind, etc., and make trips downrange less time consuming.

It was interesting that you shot the last group with various weight settings, but that might have been more informative if you noted which impact corresponded to which weight. I think a better experiment would have been to order your load block with rounds of known weight in random (or evenly distributed) order, then put one shot each into sheets of graph paper with a printed aiming mark. I would have tried to have a fairly dense/uniform distribution of weights over the weight range of interest. Later you can extract POI for each shot and do a regression analysis.

Also, if you were going to go to this much trouble after weighing each, I probably wouldn't have coarsened your weight data by just blocking bullets. Why not keep track of the weight of each as exact as you can measure if you are going to go to all the trouble?

All of this would have been more work... :)

[DrB]

Roy, checked out your website and enjoyed the projects. Think I may have to do the PID. Was wondering though why you left the original system/thermostat/rheostat that came with the pot in place?

:hijack:

[rbertalotto]

Thanks DrB. Lots of good "thinking points" in your post. As I practice with the gun more and more, I'll keep better track of what is going on, I would think that after a while, a theme will develop that we can analyze.

I'll stay on it.

As far as modifying the lead furnace. The "dial" on both of my pots is simply a rheostat. They are not any type of thermostatic temperature control. So simply setting them to "High" effectively removes them from the circuit. I'm not aware of any of these casting furnaces having any type of thermostatic control.

[Bret4207]

I have done several tests using boolits that are visually as near perfect as I can make them and grouped in wt ranges of under half a grain, 1/4 gr IIRC. They shot good but I still had fliers and my unsorted groups were still usually only slightly larger, some were decidedly smaller! My conclusion? Well, I think air voids are an obvious issue. Another issue MIGHT be length. When we size boolits we're actually swaging them. The larger diameter a boolit, the longer it will be for a given finished diameter- unless, I think, we're compressing air voids. So there are couple things we might want to add to the testing-

Group them for wt. before sizing
Group them for length before sizing
Group them for length after sizing

Maybe that will add a new dimension into the results.

[rbertalotto]

Thanks Bret,

But I have to discount the air void issue. If you look at my boolits, they all fall within a relatively small range as a percent.

But then I have what I call "Bad Boys"..........(I was going to call them BFBs...Big Fat Bast...ds). These boolits are all MUCH heavier than the norm. I'm hoping my "constant pressure" pliers will resolve this issue.

I've cut apart my lightest boolits and I've not been able to find any voids.

Next step will be to measure the length of these BBs after sizing to see how much they actually grow in length. You might be on to something here.

[41mag]

Interesting discussion so far. While I haven't progressed into rifle boolits yet, I am quickly getting my feet wet on pouring up several different calibers and weights for my handguns. This past Wednesday, I sat down, and set up the pot with my newly acquired thermometer stuck off in the alloy, then I cleaned and lubed my 6 banger mold up, and slid in the probe from to monitor that temp as well. Turned on the digital read out and sat the mold up to pre-warm as the alloy melted.

Once thing got up to my previously marked setting on the Lee 1-10 dial settings, I started checking temps. I ad previously marked my setting when I poured my initial batch of Lee 300gr boolits for my 454 and figured this would be an easy way to remember.

This said the WW alloy reached 675 as a top end temp on the thermometer. I allowed plenty of time for it to stabilize and started to pour. The mold temp was initially 215 degrees and the first couple of pours resulted in some wrinkles. It warmed up quickly to 310-320 before I noticed frosting just starting to form on the noses. At this point I really wasn't counting seconds between pours I was just simply running things up to see about where things started to change.

So I cooled the mold down to about 295 and poured two full loads as the 10 second timer reset the temp on the meter. So now I was using the 10 second delay between temp checks as a timer. This proved to be fine and allowed me to cast around 6-8 pours before I had to once again cool the mold with my fan.

I poured up close to 60 or so before the sprue handle called it quits and broke off even with the bolt. So not to let a good thing pass, I simply swapped molds and went on to another Lee 6 banger for the 210gr WC 41 cal TL. For this one however I had drilled the hole out for the thermocouple to me inserted in. So I just poured until I had about 6 or so through it and cooled it down a count of 20 in front of the fan, then resumed again until the TL grooves started to get a bit frosty.

I ended up with a bit over 50 of the 41's before I decided to try out yet another mold I had found off in a box of shelved stuff and just cleaned up. It's the Ideal 358311 160gr RN. THis being totally new to me is a well used old mold. I figured I would throw out a bunch just to see how they poured and how they might shoot in my TC's 10 and 12" barrels. Anywho I close to 60 of them keeping the temp in the pot sitting around the initial 675'ish area.

Sorry to have put up such a prefix to this, but I'm new to all of this and working hard to get my feet under me and on to producing consistent boolits to be utilized for hunting. This said, I had hoped from reading the initial post that by weighing out my newly cast boolits I would have come back to hopefully find quite a few comparisons among the post on accuracy variations from separating by weight, or keeping the temps in an average span to produce boolits of certain weights more consistently. Don't get me wrong, I am still very interested in this, and know from a couple of other treads that I'm on the right track.

My results were as follows with my little bitty sample,

On the Lee 300's I randomly grabbed up 15, which averaged (8)306.20grs +/- .02. The heaviest of them weighed (2)308.10 and the lightest was (1)301.70. The other3 were between 304 and 305.8.

On the 41's out of 20 grabbed from the pile, I had (9) @ 213, (5)@ 214, (3)@ 215 and the rest were under 211grs.

For the .357's I snagged 10 which went (5)@163, (3)@ 162 and the other 2 under 161.

So I realize I don't qualify for the most detailed study, but what did strike me odd twas that most folks rarely if ever even weigh their handgun bullets. I might be anal about a few things, but figured that if I was gong to go through all of this to "make" my own bullets, that I should at least throw in some QC, other than simply looking them over just to make sure they don't have holes in the bottoms.

Should I even make this effort to weight out and separate them? Is it really going to mater at ranges of 50 - 100yds, with boolits ranging from 140grs thru 310grs? I'm not shooting matches, but I generally do my best to load my ammo to match quality if possible. So is it reasonable to expect the lower velocity rounds to shoot good even with the weights being separated by a decent spread of say 4 or more grains?

[rbertalotto]

Great post Mike. Thanks for taking the time to do this.

I just statrted using a BBQ thermometer on my molds. Result will be posted as I cast more boolits.

[rbertalotto]

UPDATE:

Results with "Constant Pressure Pliers Handles"

I finally had a few moments to analyze the results of using the constant pressure handles I built;

http://images55.fotki.com/v608/photos/2/36012/9869255/P1020784-vi.jpg


As you can see. Huge improvement. 3.7g variation. I'm still not sure how you folks are getting 1/2 grain variations. I have a long way to go to get there. But this is huge for my stage in the game.

Here's a quick video of how the pliers are connected to the temperature probe.


http://public.fotki.com/Rbertalotto/gunsmithing-reloading/constant-pressure-m/p1020782.html


BTW, I found my best bullets were cast with the "1-20" Allot at 750 degrees and the Lyman mold at 425 degrees..........

Thread on the constant pressure handles:

http://castboolits.gunloads.com/showthread.php?t=121114&highlight=rbertalotto

[41mag]

Well I dumped a bunch of 300gr boolits yesterday minding the pot temp and mold temps as posted above. I haven't gotten a chance to run them over the scale just yet as there were simply too many of them to deal with last night. I also dumped quite a few of the 230gr RN TL ones for my 45 which will also get weighed up. I'll post my results as soon as I get them weighed.

Also found that my thought of using a 1# Folger's plastic coffee bucket for storage might have to be dedicated to something else, as when I was done picking through the 300's, I had it full enough I could just snap the top on and then could hardly pick it up.:o Those darn Lee six bangers sure are nice to use,but they sure do empty the pot quick.:grin:

Oh yea, in the above post I noted that I started to see some frosting on the boolits when the mold temp got up to around 320 degrees. Well it turns out that is was actually caused by a heavy area of soot from when I sooted the mold. I noted it again yesterday, and stopped and checked the mold. I dusted it ever so lightly with a fine hair paint brush and cured that right up. Not like the other boolits will shoot any different from it as it was purely superficial, but the ones from yesterdays pour were all very pretty.

[rbertalotto]

Mike, if you could plot them like I did above, that would be greatly helpful to the cause.

Thanks

[44man]

I have had funny results weighing boolits and sorting them. I never remember shooting better and seem to have more luck just taking them out of my box and using them as is.
So after reading this I took my 320 gr 45-70 unlubed boolits and weighed them. I only had 50 left. Most were within .2 gr in each pile, many were exact. From one side to the other the highest weight change was .8 gr and I had three piles.
These were from my home made two cavity mold and ladle cast.
I don't think the scale will ever be put to use weighing boolits again! :veryconfu
I suppose little bitty boolits should be weighed but will they vary more then store bought J word things?

[rbertalotto]

I must be doing something wrong or it's the salt air here on the east coast. I'm all excited when I see a 3.8g variance over 130 bollits and folks are telling me they are seeing a two tenths of a grain variance!

I suck at this boolit casting stuff.............[smilie=b:

My Benchrest rifle, custom boolits (J-word) will be within .3 to.5 grains for a 65 grain boolit out of a box of 100. It amazes me that folks are seeing smaller tolerances with heavier boolits with all the inherent variables that lead casting introduces.

Onward and forward!

[pdawg_shooter]

I am NOT a target shooter, just a hunter. I do weigh my rifle bullets and reject any over 1% + or -. A 400 gr bullet is accepted if it falls between 398 and 402. I average 50 bullets and apply the 1% rule, load and go hunting. For handguns, if it looks good it shoots good. Works for me.

[rbertalotto]

I agree on the handgun boolits. And just about any boolit shoots "good enough" out to 50 yards.

But it's those 600 yd shots that really get your attention and all the little stuff gets exagerated.

[btroj]

For a BPCR rifle the weighing makes sense. The difference on the rams will be enough to matter. For 100 yard shooting I can't se spending e time worrying it. Then again I am not a bench shooter.

This is definitely one of those niche things in casting. I feel the same about your constant pressure handles. For BPCR they make sense, for a hand gunner, no way.

With weighing you will need to pay close attention to slight changes in rhythm, pot temp, etc. So many things can give that slight variance you want to avoid. You are truly trying a very technical, difficult area of casting. Good luck.

[41mag]

With weighing you will need to pay close attention to slight changes in rhythm, pot temp, etc. So many things can give that slight variance you want to avoid. You are truly trying a very technical, difficult area of casting. Good luck.

Well for me, my personal goals are simply to be able to control what I am pouring and get somewhat more consistent results from it. As far as sitting down and weighing every single bullet I shoot, nope ain't going to happen. I know form past experience that event eh factory J's vary sometimes quite a bit, but I still am able to shoot tiny groups with carefully developed loads. This said, I at least know they have some sort of tolerances that they allow, and also QC most of their products.

This is simply all I am doing, gather enough info that when I set up for a pour, I know within reason that by keeping this, that and the other consistent, I will end up with at least something VERY close to what I had before. Since this is all new to me, I gotta start somewhere and this doesn't seem such a bad place to start.

[ColColt]

OK, I'm going to ask if no one else will that doesn't have a set of those "gussy" handles. It seems to me there should be two wooden handles instead of one as you generally expect else how are you going to keep your right hand from getting burned. I looked a them on Cabintrees' website and couldn't help wondering. Maybe I'm not getting the right picture. I know gloves help but maybe that's all that's needed.

[41mag]

Ok here is my contribution to this. I ended up with 286 from yesterdays pour.

I separated them in 2gr increments, starting at 300grs, and going up to 310grs. The lightest one I weighed was .297grs, and it went with the other 6 culls I tossed as I went through them for the second time.

So here is what I ended up with,
http://i49.photobucket.com/albums/f285/41nag/Shooting/Cast%20Boolit%20Loading%20and%20Shooting/P7110234.jpg

Top row was 300 - 302grs, second row was 303 - 305grs, third row was 306 - 308grs, and bottom row was 308 - 310grs.

Out of these I noted that the second column contained around 75% weighing 305+grs, the third column contained around 80% weighing 307+grs, and the last one contained roughly 50% at 308+grs and the others at 309+grs, with only one hitting the 310 mark.

I doubt very seriously that I would ever notice the differences in them if simply loaded and shot. However, it is nice to know that even with my rookie pouring I am still pretty darn consistent with keeping them mostly within roughly a 3 grain span. I have to give credit to the folks that posted up previously on what temperatures they normally pour at and what they try to keep the molds at as this was around the same area I was pouring mine at. Keeping the pot between 675 and 700 and the mold between 300 and 335 for the most part. There were times where it reached up to 350 but this was usually when I loaded it up when it was already pushing 330, and the added pour would jump it up.

So there ya have it. I am happy with my results, and will probably simply pour from the second row down back in the 1# plastic can and wait until I am ready to lube size and shoot them. They should make some pretty nice hunting boolits for sure. The others will go back in the pot to be poured again, and hopefully hit the mark a little better with the second time round.

[btroj]

Looks like you have the hang of it. Bet some of the light ones were early in the pot, mould was a bit cooler.

I would say that for all but accuracy games you could loads them all and shoot them.

[rbertalotto]

Thanks mike, very helpful

As you can see, you are experiencing a 7g variance with a 300 grain cast. The exact same ratio I was experiencing with my 500+ grain boolits.

That said, I'd still like to see how folks are holding .2g variances. I'm begining to wonder if their scales need calibration :mrgreen:

As one of the other posters noted, it's all a mater of your expectations and what you want to obtain in your accuracy. Benchrest shooters will weigh primers to have ABSOLUTE consistancy. Bullets with even a .1g variance will be set aside. Brass is weighed and culled. But these folks NEED all ten boolits to go into one small hole at 200 yards. Nothing else matters.

My problem is, once I started shooting BR, and I have rifles that can literally hit a fly at 200 yds (I've done it a few times), and then I take out my hunting rifles or these cast boolit rifles, and I'm shooting 2" -4" at 200 yards, I'm slightly dissatisfied. So I drive myself nuts to wring the most accuracy I can out of the rifle.

To me, "The only interesting rifle is an accurate rifle"........If I just wanted to go to the range and make noise, I'd bring fire crackers. I'm not suggesting that folks that go to the range and just haul off and fire a few hundred rounds aren't having fun. I know they are. But I get huige enjoyment by going to the range with 20 extremely accuratly loaded rounds and sometimes taking an hour or more to shoot them, always looking for that super small group. This is what I shoot and reload for. Sure, there are times I take out my AR15 and a big ol bag of 223 reloads and head to the range "to make noise". Or take a few semi-auto handguns and just plink away. To each his own.

I'm having a BLAST with this cast boolit stuff........nuff said![smilie=w: