Day: October 15, 2026

Does Weighing Each Charge Matter? (Part II)

By Joe Berk

Two days ago I posted a blog on loading .223 Remington for the Mini 14 with IMR 3031, and I asked the question you see in the title:  Does weighing each charge matter?

In a word:  Yes

Some associated questions:

Does weighing each charge make for a smaller group?

Again, the answer is yes.

Does weighing each charge make the velocity extreme spread and standard  deviation smaller?  Surprisingly, no.  I saw only a small difference with the 25.5 grains of IMR 3031 loads (in fact, the spread and standard deviation were slightly smaller for the cartridges charged directly from the dispenser).

So what works best with IMR 3031 and the 55-grain full metal jacket boattail bullet in the Mini 14 rifle:  The minimum load, or a near max load?  With the bullet I used in my rifle, the near max charge was the clear winner.  Just to check out the lower end of the charge spectrum, I also loaded with 24.0 grains of IMR 3031.  The extreme spread and standard deviation were atrocious, and the accuracy was poor.  This is a cartridge that likes to be loaded hot when shooting the 55-grain bullet.

First, all the usual accuracy caveats:

    • I’m an old guy.
    • My eyes ain’t what they used to be.
    • It was windy as hell out there.
    • I was shooting into the sun.
    • I didn’t trim my brass.
    • I didn’t clean the primer pockets.
    • I used old brass.
    • The way I had my targets posted was distracting (more on that below)

You get the idea.  I have a bunch of excuses.  It wasn’t me.  I didn’t do it.  It’s not my fault. I would have made a good criminal, I think.

My targets. I shot at 50-ft pistol targets at 50 yards. The top left target was with the 24.0-grain IMR 3031 load (with the propellant dispensed from the dispenser straight into the case). The top right target was with the 25.5-grain IMR 3031 load (again, with the propellant dispensed from the dispenser straight into the case). The bottom center target was with 25.5 grains of IMR 3031, but I weighed each charge using a powder trickler to give me exactly 25.5 grains in each case.  There are 20 rounds on each target.

It may not look like much now, but you can see a bit of the black bullseye on a previous target peeking out between the two upper targets.  It’s also just above the bottom target.  That bit of black was enormously distracting using the aperture rear sight on the Mini 14.  I had a hard time hanging on to the target I was aiming at.  I didn’t realize that when I stapled the pistol targets to the target stand, and it may have skewed my results with respect to group size.  Live and learn, I guess.

Here are the group size and chronograph results:

Why, you might ask, is the standard deviation and spread slightly larger for the more-precisely-metered 25.5-grain load?  I can’t say.  There might be other variables at play I didn’t control, or it might just be normal statistical variation.  But the group size says all I need to know.  Weighing each charge makes for smaller groups, and that’s usually what I’m chasing.