General thoughts
3 shots won't prove a load, BUT it sure can cause it to be rejected from further consideration. A small 3 shot may get bigger with more shots, but a large 3 shot damn sure won't shrink.
My personal method is to use 3 shot groups for the primary workup, than retest those that show the most promise with 5 shot groups, with a 10 round group as final proof for the best of the best.

Scales, there is a difference between accuracy and repeatability. Accuracy (what is "guaranteed") is how close it is to a standard. Repeatability is how close it reweighs every time.
For reloading purposes repeatability trumps accuracy. That is to say a scale that averages +/-0.00 but varies by +/-0.5 is useless due to repeatability, but one that's off by 0.5 but repeats to +/-0.00 is highly useable.

Finicky...

Have you thought about the bullet being the problem. I switched bullets brands in same weight and had difficulty getting satisfactory results. Perhaps the bearing surface of a particular projectile is what makes it require exacting tolerances for satisfactory results.

It's just a suggestion, and I'm always right!

The once or maybe twice I had a very small difference drastically improve a group I was unable to repeat it.

Not that I recall. Then again I dont load less than .5 grain difference.

quote:

Originally posted by GSSP:
Mike,

.2 gr? Depending upon the powder scale; +/- .1 gr accuracy, could the spread be larger than .2 gr? Possibly .3 gr? Then I could see a difference. I wonder if the accuracy node is too small to keep using the same powder. Might be difficult to keep it within the same accuracy node depending upon weather, loading techniques, component consistency. Just a thought!

Now, if you have an Acculab VIC 123 or something as accurate that measure +/- two 100th of a grain.......?

Alan

I agree that .2 grain is too narrow unless you are willing to tune it for temperature. The load can't be very tolerant of pressure changes for any reason, including primer or brass inconsistency.

I had a Cooper .223 that would do the one hole thing at a particular charge. Any movement off that charge opened it up. Instead of using that I found a more tolerant load and then tuned seating depth to get back to the original group.

quote:

Originally posted by rodell:

quote:

Originally posted by GSSP:
Mike,

.2 gr? Depending upon the powder scale; +/- .1 gr accuracy, could the spread be larger than .2 gr? Possibly .3 gr? Then I could see a difference. I wonder if the accuracy node is too small to keep using the same powder. Might be difficult to keep it within the same accuracy node depending upon weather, loading techniques, component consistency. Just a thought!

Now, if you have an Acculab VIC 123 or something as accurate that measure +/- two 100th of a grain.......?

Alan

I agree that .2 grain is too narrow unless you are willing to tune it for temperature. The load can't be very tolerant of pressure changes for any reason, including primer or brass inconsistency.

I had a Cooper .223 that would do the one hole thing at a particular charge. Any movement off that charge opened it up. Instead of using that I found a more tolerant load and then tuned seating depth to get back to the original group.

Well done. I like it when a Reloader uses reasoning in his process! I commend you!

My 22.250 with .2 grain powder variations

How many times did that difference repeat itself?

quote:

I made 7 different loads starting from 44.6 thru 45.8 grains of varget in .2 grain increments.

i usually dont load in .2 grain increments. i start at .5 in most short actions. But no. see no improvement with .2 i have had loads that would shoot .50 today and shoot it again tomorrow and get .950 if i can shoot an avarge .750 load in 3 different days. thats a good load for hunting.