So I bought some Zero 124g 9mm projectiles.

I was lead to believe Zero made good bullets but it turns out that every single bullet I weighed from the lot I got is actually 125.3-125.4g.

Comparing load date for a 124 vs 125g projectile yields some pretty significant differences in both charge and COL.

For instance, using HS-6, Hodgdon says the starting load for 124g is 6g and 1.150 while the starting load for a 125g projectile is 6.4g and 1.090.

I'm assuming this bullet weight discrepancy is why I was seeing a lot of unburnt powder, my load was (a minimum) of .4g light and the cartridge was too long.

Is it normal for projectiles to be heavier than advertised or should I be skeptical of the quality control of these particular bullets?

1 grain plus or minus on bullet weight for plinking ammo makes no difference that you can likely notice.  

The different loads are likely more to do with different bullet styles, which leads to different OAL, than does the 1 gr of bullet weight.  

If I recall correctly, the 124 bullets I usually see are FMJ or RN profile.  The only 125 gr 9mm I have loaded were Hornady FN FMJ.  There is a lot of difference in how a 124 RN FMJ and a 125 gr FN FMJ get loaded.  

And with 9mm, small changes in OAL make a big difference on both pressure, and also on how well the round feeds into the chamber and headspaces.  There always seems to be one gun with a shorter chamber so you cannot load for it to the same OAL as your other 9mm guns.


If I am wrong, maybe you should post up the loads you are looking at so we can see what you mean.  

Also, different load manuals will give different recommendations for the same bullet/powder quite often for various reasons.  


So my thought is something in those loads is different, and it isn’t the 1 gr of bullet weight.

First pick a COAL that will allow all cartridges at that nominal length to easily chamber in all of the firearms you will be shooting those reloads in.  Bullet length and seating depth isn't going to be exact so you want something that is short enough to fit, minus at least another 0.005-0.010" fudge factor.

Then load a ladder starting low and working up.  I typically don't start at the min load because that doesn't always reliably cycle semi autos.

I usually do max minus 8-10%.  I'll load at least 5 rounds for each gun I want to test function in.  Shoot the workups starting from lowest to highest charge.  Look for the range that gives you the desired characteristics most important to you( function, accuracy, recoil, velocity, cleanliness, etc.)  Continue your load development focusing more in on that range.

If you want bullets that are more exact in their weight, you need to buy better bullets.  Hornady and RMR are good choices.  That said, I really don't think the difference you're seeing is going to cause any issue.  If you had a 125 gr. Bullet that you couldn't find data for, you would be using 124 gr. data to base your workups off of anyway.

Also- you asked about QC.  If they only vary +/- 0.1 grain, that is actually a pretty consistent bullet weight.  They just are not the exact advertised weight, which is not super uncommon.  

Again- does Hodgdon list the exact same projectile at both 125 and 124 gr?

Alot of the shorter coal might be for a conical shape vs a round nose.

I looked it up.  Hodgdon website lists only one HS-6 124 gr load, it is for a Berry’s plated Round nose with hollow base.  Plated bullets load like lead bullets, because essentially that is what they are.  

An equivalent load to the Berry’s is a lead conical nose 125 gr that Hodgdon lists.

HOWEVER- Zero bullets 124 grain is a copper jacketed round nose FMJ style.  

Hodgdon lists the 125 gr Hornady HAP (the flat nose FMJ I mentioned above- you don’t want that data as it is the totally wrong style).  

So that leaves only the Sierra Round nose FMJ 125 gr to compare.  And honestly, that should be a pretty close match up to the Zero bullet as it is just a different company’s version of the same bullet.


Not sure what you were looking at, but if you were comparing a plated Berry’s 124 gr to a copper jacketed FMJ you can’t really do that.  

Use the 125 gr Sierra FMJ data.  


I could have just written that had I bothered to look it up the first time and realized you couldn’t possibly be comparing similar bullets, but I got there eventually I guess...

Edit: Never mind, I think I'm reading an ambiguously worded statement wrong.

The other thing is your scale might be reading slightly different than others. Do other jacketed bullets from major mfgs weigh out to what is on the box?.


I agree with the answers others have given you , a bullet that runs less than 1% difference in weight won't change your load performance much ,messing about with the OAL because the profile or nose shape in a small case like 9mm can change things up . Bullet construction such as jacketed ,plated , cast , coated can have considerable different results