Reloading blues

[coach4christ]

Ok I'm working up a 308 load using 155 scenars, lapua brass, cci br2 primers. Rifle is a new Bartlein with the chamber cut with a bisely reamer (if that makes a difference). Anyway doing load testing this morning and my velocities were all over the place. I started with 44 grains of varget an worked up in increments of .3 grains. I loaded 3 rounds of each load. Anyway my ranges for each load was rediculously large. The smallest was 22 fps. I use an automatic dispenser. I then weigh each charge thrown on another set of scales to double check the charge weight. Both measurements were spot on last night. Where am I messing up? I was hoping to get the range of my velocities to be <8 fps. Is this possible?
Thanks for the help,
Will

 

[DT1]

New brass or previously loaded? Flash holes may possibly need to be uniformed. We're you shooting groups or just getting velocities? If the groups were good, I wouldn't worry about it too much. Could also be an anomaly with the chronograph.

Good luck in sorting it out and developing your load!

 

[coach4christ]

Once shot brass. Shot groups and cronied each shot.

 

[Lumpy Grits]

Put fresh batteries in your crono.
LG

 

[DT1]

Put fresh batteries in your crono.
LG

+1 I usually chalk anomalies like you're experiencing up to the chrono. Things like weak batteries, changing light conditions etc can make a frustrating difference in SD spread. Sounds like you're paying close attention to detail with your reloading practices.

How were the groups?

 

[coach4christ]

2 good groups around 1 inch at 200, 4 groups around 2 inches at 200.

 

[HumbleEinstein]

I chronographed about 8 different loads through my rifle with two different traditional units and had numbers that were very low and erratic. The results were not matching up with the real world either. Then I used a magneto speed and got very consistent numbers that were almost dead on compared to real world observations. I've come to the conclusion that the traditional chronograph is inherently flawed. That may be overstating, but I'm going to stick with the magneto speed and not look back.

 

[Road_Clam]

My Alpha Master is extremly fickle to light conditions. Not too sunny, not too overcast, definately doesn't like sun and clouds. When I trickle measure and I see ES's over 50 I pack up the Chrono and try another day... Had conversations with other Chrony users and the share the same experiences. The best conditions for consistant readings for me seems to be bright sun with the diffusers, or lighter overcast without the diffusers.

 

[DT1]

Lighting errors can be reduced or eliminated by putting your chrono aparatus in a wooden or heavy cardboard box. It is a cumbersome process but it tends to make readings more accurate and consistent. They are used in major IPSC matches when bullet velocity is needed to determine power factors.