Yes, they will affect accuracy, as they are a variable in the recipe, just like the powder, brass and bullets. Some powders, especially in longer cases with slow powders, need a hotter primer like the Winchester LR or even a magnum primer to light them up uniformly. Other powders would generate way too much pressure from a hot primer and a full dose of of powder. If you buy 100 primers, load up a recipe with works for you and shoot a group of 5. If it is good, run back and buy more of the same lot, and mark them as such. Date them. They last a long time, but the point is to know what batch you have of each primer.