I would check the scale with the test weight before each loading session and if it's only off 1/10 of a grain I wouldn't worry about it.
I promise you the electronic scales used in reloading have at least that much variability. I don't know how accurate the Lyman weights are, but I would suspect they show a bit of variability from run to run. You may be able to call Lyman and find out if the weights are NIST traceable, even then Lyman is going to have an acceptable range for their QC department to use. If you really want to be anal retentive you could send the weights to NIST to have them checked.
What really matters is consistency, just make sure that your indicated value doesn't change between loading sessions. That way you know when you measure 25gr on your scale it is repeatable, don't get hung up on 0.1gr error, that's plenty accurate for a reloading scale. Your powder measure will throw charges +/- 0.1 - 0.2gr depending on powder choice and you will still have accurate safe ammo. What will really drive you nuts later are different loads from different manuals for the same powder, in addition to watching those loads change over time.
What really matters is consistency, just make sure that your indicated value doesn't change between loading sessions. That way you know when you measure 25gr on your scale it is repeatable, don't get hung up on 0.1gr error, that's plenty accurate for a reloading scale. Your powder measure will throw charges +/- 0.1 - 0.2gr depending on powder choice and you will still have accurate safe ammo. What will really drive you nuts later are different loads from different manuals for the same powder, in addition to watching those loads change over time.
+ or - .10 is not going to make a difference, as stated consistency is the important thing to watch for. Find your rifles load and get busy.
0.1 of a grain? I normally have a variance in powder of 0.2 up or down even on pistol powder before I even start to worry about it,unless you are loading for say .25 auto then you may want to stay on the low side. I have never owned a check weight and just use a jacketed bullet from a respected manufacturer every once in a while to check my scale.Also you can use new pennies,I don't remember what they weigh but its on the internet somewhere.
Also as was said,consistency is more important than exact weight. The reccomended powder charges are just that,a reccomended place to start and stop. I have had blown primers before I ever got close to a max charge before,start on the low side and watch for pressure until you find an accurate load.Do not try to magnumize a cartidge,accuracy usually goes out the window,buy a magnum for that.I have also found that around 96% -98%of max is usually where the best accuracy from a rifle happens,YMMV.
Also as was said,consistency is more important than exact weight. The reccomended powder charges are just that,a reccomended place to start and stop. I have had blown primers before I ever got close to a max charge before,start on the low side and watch for pressure until you find an accurate load.Do not try to magnumize a cartidge,accuracy usually goes out the window,buy a magnum for that.I have also found that around 96% -98%of max is usually where the best accuracy from a rifle happens,YMMV.
Like what they said. Start low and work your way up.
How low, well it doesn't have to be the lowest stated charge.
But you dern sure don't the top/hottest one either. Work your way up to it and keep an eye out for stress.
Be sure and write down the charge weight and primer so you can duplicate a good working load or adjust from previous ones.
