Have found E-Tips to shoot best when seated up to .1 inch deeper than lead-cored bullets, including Ballistic Tips.

Any of the 4350s (including Accurate's) will generally work with 100-grain bullets in the .257 Roberts, along with IMR4451, which is very similar in burn-rate. So will a bunch of other powders with a burn-rate on either side of the general 4350 will work as well. Have gotten excellent result, for example, with Ramshot Big Game and Hunter.

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