I went to a range just north of Blacksburg, VA today to try out the new Chrony.  I got the Alpha model Shooting Chrony. I have to say, it’s a cool piece of a equipment. Cool in the sense that I now know my loads are pretty inconsistent. I’m on par with Wolf ammo, which isn’t good enough for my likes. I shot five rounds of everything I had. Velocity for .223 averaged 2717 fps out of my 16″ barrel, with high being 2775 and low being 2640. Velocity for the 6.8 Remington SPC upper was 2149 on the low, 2212 on the high, with 2181 being the average.
One thing I will say, is that Silver State Armory’s 6.8 Remington SPC loads are consistent with 2421 being the low, and 2453 being the high, averaging 2436 fps.
I’m using Sierra Game King 55gr jacketed soft point, with 20 grains of IMR 4198, using CCI small rifle primers. For the 6.8, I’m using the Sierra 115gr open tip match bullets, 22 grains of IMR 4198, with CCI small rifle primers. I’m guessing my variability has to do with not precisely measuring each load? But for plinking I don’t really care too much. It’s consistent enough for that.
“I’m guessing my variability has to do with not precisely measuring each load”
Could be. If you’re worried about it you could try weighing them out. But, as long as it shoots well, velocity spread (as long as it’s not huge) doesn’t matter much until you get out past 600 yards–it matters a whole heck of a lot at 1k. Or, some loads are more sensitive than others, even if each charge is measured out. Tweak it up or down a few tenths (or grains even), change your primers, pick a new powder, etc., and you might find one really small. But, again, it’s only really necessary for long range. I don’t know what my 600 yard load’s velocity spread is (but it wasn’t particularly small) and it still holds X ring elevation at 600. (A 6″ circle–at least when I don’t let the post drift up into the black, that can get ugly)
One trick is to find a load where the load, the load plus a few tenths, or the load minus a few tents all shoot to the same spot. That way, when you throw your charges, even if it’s not right on, it still shoots well. (To do this one, with the .223, start with 19.0, 19.2, 19.4, etc., up to max) Shoot two of each charge at the same target, you’re looking for a string where three charges in a row go to the same place. The center of those loads will tend to be more forgiving of charge variation.
I do appreciate the advice. I’m still new at this.
I don’t recall the exact numbers, but I believe I was getting about 2800 fps with very little variation using 52g soft point Hornadays over 26.5g of H335.
One thing I noticed early on was that the powder dispenser that came with my Lee reloading press was a lot more accurate with the pistol powder than with the rifle powder.
Also the little yellow powder scoop that came with the kit delivers a near-perfect 26g of 335 every time. That and a trickler, and I can weigh every charge. It’s slower, but rifle rounds take about twice as long to load as pistol rounds anyway, so the net increase isn’t that great.