Verifying weights of cast bullets

[Blackhawker]

Typically when loading jacketed bullets from a reputable manufacturer such as Hornady, Remington, etc, it is usually not necessary to check the weights of manufactured bullets.  I've also found that with most bullet casters, bullet weights are within a percent or two of the advertised weight.  Unfortunately, over the years I got into a bad habit of trusting what is written on a package and not checking actual bullet weights.  Well, I didn't have any accidents or anything but I thought I'd post this just as an interesting point of safety and a "good to know" kind of thing. 

For the past year I've been loading gas checked bullets for my W&H rifle in 38-55.  As a side note; the barrel was ordered to fit as an accessory barrel to the original 45-70 Buffalo Classic so the frame in which it is mounted is an actual SB2 frame.  I have ordered bullets from a bullet caster (name not revealed here) and have been quite satisfied with the product.  The bullets I typically use are 265g FNGC's.  I've decided to try another caster due to price and  recommendations from other members here.  The new source of bullets arrived the other day and for kicks, I decided to weigh them to check for consistency.  The new bullets I had ordered are 255 RNFP with plain bases (no gas checks).  As I weighed them, I was surprised to find a lot of variances in weight, running anywhere from 249 to 256 grains.  Most of them were actually 250 grains as opposed to the listed 255 but this is to be expected due to alloy densities etc.  After weighing these bullets, I decided to check the bullets I have been using for the past year to check to see which caster has a more consistent weight.  What I was surprised to find was that the 265 grain bullets I have been loading for the past year are actually 286 to 290 grains.  That's quite a bit off from the listed 265 grains. 

OK, what am I getting at here?  Without verifying the weights of the bullets ahead of time (as I should have been doing), I may have come to problems as I approached published max loads for 265 grain bullets when I was unknowingly loading bullets of nearly 10% more mass for that given charge.  Again, fortunately, nothing has happened probably due to the fact that the published 38-55 loads are typically listed for low pressure rifles and the SB2 frame can withstand much higher pressures.  However, had this been a different load for a rifle of pistol of lesser strength, I may have run into some problems. 

Admittedly, I was a dope for not verifying the weights of the bullets but I leave this message of my mistakes as a reminder to others to do so when purchasing bullets from various bullet casters or small name businesses.   

Just out of curiousity, has anyone else come across anything like this in the past?

[Steve P]

Bullet weight is going to vary depending on the alloy being cast.  For this very reason, a buddy and I will make up a large 100-200 lb batch of ingots at a time so our alloy always stays about the same.  Difference is generally within a grain or two so we do pretty well.

When you are working up loads and are starting at least 10% below book max, you should be ok regardless of the weight of the cast bullet.  This is as long as you are working up loads that are at least 10% below max for that given cast bullet weight.  i.e. if 30 grains of powder is max for a 250 grain cast bullet, if you start at 27.0 grains, or less, you should be ok, even if your 250 grain bullet mold and your alloy actually weights in at 270 grains.  There are exceptions to this rule and one of them is when using H110 or WW296.  You need to confirm bullet weight and powder weight with book loads.

My buddy and I also weight our bullets if they are used in competition.  He weights his bare.  I weight mine with gas check and lube.  (It doesn't make a difference which method you use as long as you do it consistently with a given load for a specific gun.)  We keep them within 1.0 grain.  As in the example above, if I am casting a 250 grain bullet, everything from 249.0 - 249.9 goes into a bucket.  Anything from 250.0 - 250.9 goes into another bucket.  Anything from 251.0 - 251.9 goes into another bucket.  etc.  We then load boxes of 100 that are within the 1.0 grain.

Years ago I talked to several of the bullet makers and asked them what constituted a #1 bullet vs seconds.  Most said the right finshed look and weight that was +/- 3%.  You can see why a lot of competition shooters will weight their bullets.  Using the +/- 3% for a 250 grain bullet is 242.5 - 257.5.  I am thinking 15 grains variance in bullet weight will make a difference in accuracy.  Some guys will poo-poo this statement saying it doesn't matter.   I think it does.

If you have a mold that has more than one cavity, a lot of time you can confirm if each cavity is casting consistently.  For example in my second paragraph above I mention sorting to nearest whole grain.  Based on normal curve the majority of my bullets should land within 3 or 4 grains and I should have a few heavier and a few lighter.  If I find that about half of my bullets weight near 245 and the other half weights nearer to 250, then maybe my two cavity mold is not casting the same.    Again, may not be that big of a deal, unless you are looking for that added accuracy along with the lower cost.

Bullets that are lighter than typical or heavier than typical can either be melted back down (what my buddy does) or used for plinking rounds (what I do.).

Lots of good reasons to weight cast bullets.

Steve

[Blackhawker]

Steve, I absolutely agree that the alloy density will give variances in weights.  1 percent difference on a 250 grain bullet isn't all that bad but I do think that 3% on either side is pretty bad and one will more than likely see some accuracy issues.  Since I don't shoot any kind of competition shoots, I'm fine with being a few grains on either side of say a 250 grain bullet.  The bullets I use are by no means rated as competition grade.  I plink a lot so I shoot low budget stuff when I can....if it's decent quality.   I refuse to shoot crappy stuff or bullets that vary 15 grains or more (3% as in your example).  I put too much time into loading to do that. 

The thing that really got me was the bullet sold as a 265 grainer.  Even the mould number suggests 265 but when I found them to be almost 290 grains it was sort of a "wake up" call.  Again, fortunately, this is a 38-55 load and the published data is fairly low pressure stuff.  I do agree that with some of the ball powders, this can be an issue.  Nonetheless, I just thought I'd pass along the story so that other people don't make the same mistake I have and possibly have problems with their loads or even an accident.

Thanks for the comments Steve....good info there!
Chris