.1 grain of powder

Does .1 grain of powder make a big difference in 45 ACP @ 50 yards.  My Dillon Square Deal will not throw consistant loads. Target is 4.1 but it drops a few @ 4.2

Nothing I would be worried about.  Many set reloaders set powder measure based on an average of at least 10 samples - exactly to account for such variances.  For me, a .1 variance is well within acceptable limits.

Tap the hopper before pulling the handle, that may help.

Sorry for it being upside down, but these two targets were when I shot up some leftover chronographing ammo.  The loads were 3.8, 4.0, and 4.2 of two powders Bullseye and 452AA.  The gun isn’t a full-up “Bullseye” gun but the accuracy is at least equivalent to a Springfield RO.  Anyway, the shots outside the main group were called.  Since I was just using up ammo, I didn’t adjust zero.  But the upshot here is that there was .4 grains difference in the loads and they still shot well.  A .1 or .2 grain difference won’t amount to much.

A good gun will shoot a range of loads well. In my testing my gun shot 3.9-4.1 in the same roughly 2" group at 50 from a ransom rest, of the 9 total loads (different powder/bullets) I tested they all averaged 2.5". Clearly this was my gun and ammo that I loaded, your gun and loads may have different results.

Not sure what powder you are using but some powders also meter better in some powder measures than others.

Just getting back into Bullseye. Forty years ago Uncle Sam provided all the ammo I wanted and it shot well in our pistols. Now I have to roll my own. Great information from all, appreciated.

Makes no noticeable difference in my experience…..spend your time perfecting trigger control and sight alignment. Far greater dividends.

What everyone else said above, your loads should work fine.  I also load 45 on an SDB.  Make sure you are using the small powder measure bar.  I load with WST, it meters very consistently.

I had a SDB 30 years ago cost me 189.00 shipped from Dillion.

Dumped powder in 10 case then weighed total. Ended up @ 4.097 grains average. I dont think I can get any closer to 4.1. Thank again for all the input.