Acceptable weight variance in cast boolits

[Ken77539]

I was curious - I just spent the last couple of days sizing, sorting and weighing out about 2000 rounds of cast boolits in 9mm, .44 and .45 calibers and found that in each caliber the weights varied from 3-4 grains from high to low. I load my cartridges usually in lots of 50-100 rounds and would like to get a consensus on what the CB community would consider an "acceptable" weight variance within a given lot. This ammunition is just for plinking - no hunting, competition or PD - but even so, I would like to maintain a certain degree of consistency in performance.
I have them sorted out to the last grain and will eventually load them this way, but for my intended purpose, am I being too critical?

Thanks.

[onondaga]

Some shooters say +-1% of average bullet weight, so for a 300 gr bullet that is +-3grains.

For match bullets I sort to +- 1 grain no matter the bullet weight.

When working up a load for accuracy, I DON'T use bullets sorted for weight until I get a load that groups less than 1 inch at 50 yards for rifle or pistol because so very many other factors are much more important to accuracy than boolit weight. When I get the 1 inch group with unsorted boolits, sometimes the sorted boolits don't even make a difference when you have the optimum accuracy sweetspot load. That is a good thing to happen.

The best I have done is reduce a .720" group @100 yards to a . 410" by matching boolits +- 1 grain instead of +- 3.5 grains with a 30 cal 152 grain rifle boolit ----What does this matter to anybody but a nutball like me with too much time on my hands? That is the difference between an eye socket shot and an eye pupil shot......really!

Gary

[FAsmus]

Ken;

There has always been considerable cussing/discussing about as-cast bullet weight ~ all you will see here will probably be a re-hash of what has gone before: Each shooter giving his view and you figuring out what you want to do with it.

For me, weighing bullets I intend to shoot for matches, fun or informal practice shooting with friends in long range big single shot rifle shooting is part of the casting process: I weigh each bullet right when it drops from the mold. This additional procedure provides me with instant on-the-spot information about what causes weight variation ~ that being alloy heat, mold temperature and casting cadence. If all these are held within certain perimeters bullet weight will follow pretty easily within +/- 0.5 grain for the whole lot. (These being bullets that weigh 500+ grains each) And, when an odd weight fluctuation shows up I have a pretty good idea about what caused it.

For pistols I must admit I have never weighed any bullets at all besides establishing that they are what I expect from a given tool. The short guns have always done well for me, but I never used them for match shooting.

The 30 and 7mm rifle shooting I do is pretty much the same: visual inspection is all I bother with and this includes bullets I use for shooting in the CBA Postals.

But, back 25 years ago in schuetzen shooting I used to weigh my bullets within +/- 0.15 grain ~ and I really don't know that it did any good.

Good afternoon,
Forrest

[RobS]

The difference in your boolit's weights are not likely to be seen with the cartridges and purposes you are using them for. I wouldn't sweat it. I don't weight my handgun boolits but I do for accuracy in my rifles. Casting rhythm (tempo), mold temp and pot temp have a lot to do with keeping weight variances closer.

[FAsmus]

Gentelmen;

In doing the weigh-as-I-cast program I have learned that fill technique is a big variable.

Now, I cast by the ladle method and can't speak for you bottom-pour fellows but if I fill by fitting the ladle to the mold and turn it over for pressure feed I will get a certain weight, say 492 grains from my favorite 44 mold. Then, same alloy, same day and one cycle from the 492 grain bullet and I go to the Ed Woskia pressure wave method the weight goes up to 496 grains, consistently!

All tools have certain individual "preferences" for fill-method of course but this difference has been noted in pretty much all my casting.

Good day,
Forrest

[RobS]

FAsmus:

Good point on fill technique and sprue puddles. Keeping things consistent with any approach will yield more consistent boolits.

[altheating]

Years ago when casting for my Rem 700 Muzzleloader is was using a RCBS .45-300-FN mould. (I think) It would cast boolits of 333 gr filled out. It would also cast a lot of 330 grainers. I would weigh every one of them, throw the 330 grainers back in the pot. The lighter boolits just would not shoot in that muzzleloader. The 333 gr boolits would cloverleaf at 100 yds. Hard to beleive 3 grains would make that much difference. I now weigh every one! I think it makes even more difference with the smaller caliber boolits. I cast, figure out what the heaviest boolit is and keep them, everything else goes back in the pot! Thats just my way, I'm sure there are many other opinions on the subject.

[Hardcast416taylor]

Ken. This is what I have adopted as a plan for acceptable cast bullet weights. After you are done casting grab a large handful from the total pile. Weigh these bullets and sort them as to weight. If there is no greater spread than 3 grains - don`t get excited about the weights of the rest of the pile. For a variance as small as 3 gr. - load em and shoot em! If you are looking at match weights or super hunting close weight, then sort out enough of a similar weight for that purpose and load and shoot the remainder.Robert

[williamwaco]

You are asking specifically about handgun bullets. I have fired a zillion handgun bullets I cast myself. For MANY years, I never weighed a single bullet. They were inspected visually only.

A couple of years ago I bought a Thompson Contender in .357 magnum and scoped it with a 2.5 to 8x weaver. I was pleasantly surprised to find my unweighed "plinker grade" loads produced below 1 inch five shot groups at 25 yards and about 1.5 to 2 inche groups at 50 yards. I thought "Wow what would happen if I used matched cases and weighed the bullets?"

I visually sorted about 1000 Ballisti cast #651 and Lee 358-158-SWC selecting only bullets that were visually perfect.

I then weighed every one of them. I found a maximum variation of about 6 grains in both bullets. In both groups 90% of the bullets fell into a 2 grain range. I wound up with four groups of bullets. Two groups from each mold and all the bullets in each group weighed within a one grain variance. eg 156.0 to 156.9 and 157.0 to 157.9. All the bullets that fell outside these groups were tossed into the plinkers box.

I then bought two boxes of L&B .38 Special Wadcutter ammo to get a supply of matched cases. (Ouch! that hurt.) ( This factory ammo was phenomenally accurate at 25 yards.)

Now I was ready to be amazed. I knew I was about to prove two things: The Ballisti-cast bullet was going to out shoot the Lee bullet and the accuracy was going to amaze me with bench rest-like groups.

Well, I was amazed:

This is what I found.
The Lee bullet was slightly more accurate than the Ballisti-Cast and the groups at 50 yards shrank but not enough to notice visually. Averaging over 20 groups with each bullet, the average group shrank by no more than 1/8 inch at 50 yards when compared to loads with unsorted commercial cases and unweighed bullets.
All groups were fired with bullets within a one grain weight range.
( And yes, If there are any statisticians on here, I am aware that those results are not statistically sufficiant to prove one load more accurate than the other.)

And I know you will ask.
There were two loads. 4.0 grains Accurate No.2, and 4.5 grains Unique.
There was no difference between the accuracy of the different powders.
CCI small pistol primers.

WOW. Isn't this hobby great! There is never a dull moment!
You can learn something new every day, and there is no end to things to try out.
AND almost every new experiment rewards me with a surprise ending.

[Longwood]

Now if you were to take a wide spread of bullet weights and mismatched cases and do a similar test, I would love to see the results.

[brad925]

Consistant temp, distance from the nozzle on the bottom pour pot and rythm is the key. I casted 250 rds of 45-70 with my Lee 405 HB mold last week and when weighed they all were between 398 and 400 grs.

[williamwaco]

Now if you were to take a wide spread of bullet weights and mismatched cases and do a similar test, I would love to see the results.

May do that one day.

Right now I am testing flat based perfectly square base handgun bullets vs the same bullet with varying degrees of rounded base.

[Longwood]

May do that one day.

Right now I am testing flat based perfectly square base handgun bullets vs the same bullet with varying degrees of rounded base.

Another good test to do is nick some bases and shoot them to see what happens. If my base has an even, but rounded edge, I shoot them.