That will all depend on your gun, and the powder. There are as many opinions as there are powders. I have guns that will only shoot true black powder, and a few that shoot synthetic better that true black. The newer "in-line" guns...
http://wiki.answers.com/Q/What_reacts_like_black_powder
Make up several ounces at a time, and keep in the fridge, that way you have another feeding ready to go, (you just heat up slowly in a pan or bowl of warm water).
http://answers.yahoo.com/question/index?qid=20091231085...
The Ezi-action® Powder Measure enables an accurate quantity to be measured not estimated. It has been found that wastage or overuse can be as high as 20-30% where a scoop is used.
http://www.nzpump.com/powder-measure.html
It all comes down to your question, doesn't it? http://en.wikipedia.org/wiki/Smokeless_powder Single base powder has a shelf life. Double base powder has no know shelf life, such as ball powder. A little research on the subject and the eas...
http://www.benchrest.com/forums/showthread.php?p=483025
The accuracy of the powder measure will remain the same. But, the adjustment will become much more fine and easier than the stock way. No more stumbling with tools.
http://www.mrdial.com/faqs.html
Consistency is the name of the game in reloading. I agree with the first two posters. It will change the point of impact of the round. Tune your rifle to that cartridge...keep your reloads the same...shot will fall on same spot. A few grain...
http://answers.yahoo.com/question/index?qid=20080810053...
Sorry, we don't have your rifle here, nor do we use a crystal ball. What shoots well in our rifles may not work in yours. Each rifle and set of components combine in a unique way, making an exact prediction of accuracy in another rifle impo...
http://www.speer-bullets.com/about_us/faq.aspx