sorting bullets by weight

[TommyD]

Hi Veral,

I have another question of a more general nature, so I am starting another topic.

After casting bullets, how precisely should I be sorting them by weight? I have seen some postings by long range precision rifle shooters who segregate their bullets by a tenth of a grain, but that seems a bit excessive. Of course how tightly you weigh them will probably vary as a percentage of the total bullet weight. A 1 grain difference in a 60 grain .22 bullet is much more significant than a 1 grain difference in a 300 grain .45 bullet.

In my case, what kind of variance should I allow when casting a 260 grain .45 bullet? .1 grain? .5 grain? 1 grains? 2 grains?

With a large enough sample size, almost anything can be statistically significant. But what is the balance point for PRACTICAL significance? Where does it begin to make a noticeable difference in accuracy?

Tom

[ND Sharpshooter]

If you're shooting those 260 grainers in a revolver, I'd say + or - 2 grains from average would be good.  For longer range, + or - one grain.  With my 360 to 420 grainers for 40-65 use, I group them into two grain intervals.  For example the 417 and 418's together, the 419 and 420's together, the 421's and 422's together and all the others get remelted.  Also, I'm using a two cavity mould.  With a one cavity mould I'd cut back one grouping.  Works for me; HOWEVER, I'm NOT into beating out everyone else out there shooting.  I'm in this for my personal enjoyment, not competition.  In the eyes of those serious competitors out there, I'm a non-factor.  Depends on your goals.

[Veral]

  Depends on who made the mold and how careful you cast.  So I'll start my answer kindly.  Try sorting a lot of bullets by weight, shoot the different lots, in what ever weight variations you want to test.  If you can't see a difference in accuracy with the different lots, don't ever do it again.  ---  Now I'm going to try to discourage everyone from weigh checking.
 
  In my book I go into some depth on this issure, and give a test I performed the last time I weigh checked bullets, 20 some years ago!  Since that test I like to say. "Weigh sorting is something people do when they don't know how to make their bullets shoot accurately."  I expect that is a bit candid, perhaps even mean, but I don't like to have people lead into chasing their tails with meaningless work that ruins all the fun of casting bullets.  So the statement is kinder than reccomending weigh sorting.
  To keep the account real brief, unsorted shot as well or better than straight run, and the culls, by weight, shot as well as the close weight groups.

  If you are using an LBT mold and cast per the instructions there will be no weight variation in bullets from each cavity, though there is often 1 or 2 tenths of a grain difference in cavities.  I once cast 100 bullets and weigh checked each one.  The result was exactly 50 of each weight.

  The only reason weight variations in cast bullets cause inaccuracy is if they have invisible internal voids, and LBT mold design eliminates them if you run it hot and keep the mold tight shut with every cast.  Bullet design has far more to do with good accuracy than slight weight variations, so if you are straining out nats to tighten accuracy with a poor design, you are fighting a losing battle.  If the design is strong and the bullet properly fitted, and barrel lapped (with most barrels) slight weight variations won't effect accuracy enough for the average shooter to find it.  Especially handgunners.

[Lloyd Smale]

veral hit this one right on the head. Bullet design is the most imprortant part of an accurate load. Powder and primer seating dept ect come second and bullet weight variations come in last. I used to sort all my bullets and recast the ones that were out of my specs. Then my best friend who shoots more and is a better shot then just about anyone ive ever met came to the house one day while i was sorting and said he take my rejects. He even took the ungly ones. He left with a smile on his face. He later told me to shoot groups with the worse rejects i had and see how it turned out. Well after alot of testing my standards is whats a reject changed. I no longer weight any cast bullets. Small weight variations me very little at ranges out to 100 yards if anything. Even wrinkled bullets and deformed based bullets will shoot surprisingly well for plinking. If i was going to enter some long range rifle competion id probably sort bullets but bottom line is a handgun is a pretty crude instument with a lot of variables and a few grains of bullet weight is a small problem in the big picture.

[Steve P]

A buddy and I have a lot of molds.  Several are from Veral.  We shoot silhouette.   I know we both weight the bullets, however I do not know my buddies method.  I sort mine to nearest full grain.  if 139.9  it goes in 139 grain bucket.  If 140.1 it goes in 140 grain bucket.  etc.  I cannot say one batch is more accurate than another.  However, I can say that our scores improved by several targets per match by doing this.   I save the extremely different weights for barrel fouling, plinking loads, etc.  Anything that pops out 100 bullets within that full grain cup gets loaded into a box of 100 for match ammo. 

This doesn't sound like much, and for light weight bullets, probably isnt.  But our 200 grain 358 bullets when weighted into 1 grain cups are now + or - .5% variance.  No-one sells bullets to this variance.

Steve   

[Smokin7mm]

OK, I am the "BUDDY" replying. 
I basicly sort by weight to an extent.  I do it to sort out the defective bullets (ie; unseen voids).  Similar to what Steve does to basicly eliminate any that are extreemly under weight.  I will say that Veral's moulds are the best casting that I have used and produce almost 100% keepers.  I think that out of say 1000+ bullets cast that about 98% fall within that 2 grain range, with the bullet in this case being a 41cal 240gr LFN.  In fact if I actually sorted down to the .1gr and then took the center of the grouping it would probably fall within 1 grain but that is way too much work. Those that are under could be due to the mould not being fully up to temp.  When I sort I use a dillon electronic scale, throw the bullet on the scale to get the rough weight.  I do not wait for the scale to lock on to the weight as I know instantly if it is a "keeper" or not.  With Verals moulds this is probably more piece of mind than anything else.  Bullets from his moulds cast more consistantly than any other I have used and they do shoot!.  I purchased a FA 41mag a while back and had a mould (lyman 220grSWC GC) already.  I did quite a bit of load testing with this bullet and the results were VERY disappointing even with bullets sorted to .1gr ( I was getting frustrated and wanted to eliminate all variables with the bullet) still the groups were horrable.  I got Verals 41cal LFN and shazaaammmmm...  the gun started to perform.  Thanks Veral. 
Bret

[Veral]

  Well, thank you Bret!  I do truely intend to have all my molds send back your kind of report!   I'm not bragging when I say that weigh sorting to .1 gr is crude compared to the quality control I put into every mold, and I can spot flaws that no customer would ever find.  That helps in holding bullet weight (and groups), close..

[calvon]

One day after casting several hundred 9mm bullets in a LBT mold I decided to weigh some. At random I weighed 20 bullets. The heaviest weighed 137.3 grains, the lightest 136.4. Mean weight was 136.9 grains. Extreme spread was 0.9 grains and standard deviation was 0.2 grains.

Since then I have paid no attention to weights. I wait until the melt is up to about 800 degrees before casting and I preheat the mold by dipping it in the melt prior to casting. I have very few rejects.

Metal is straight wheelweights.

[Veral]

  Beautiful report.  That's the procedure I reccomend.  Get the mold hot before saving bullets, then save all that don't have apparent visual flaws.  And you're using the cheapest alloy available.  Weights would get slightly tighter if the alloy contained more tin, but groups probably wouldn't be a solid proof that the money was well invested!