You may already know this, but lead / jacketed / all-copper load data is different because of different friction developed by the different materials.
So cast bullets are going to have different data, even if they are the same weight as a jacketed bullet. I believe lead friction is lower, so less pressure. Substituting lead data for a jacketed bullet may cause dangerous overpressure.
And all-copper bullets (like Barnes) are going to have different data, even if they are the same weight as a jacketed bullet. I believe all-copper friction is higher, even with multiple grooves. Substituting jacketed data for an all-copper bullet may also cause dangerous overpressure.
But the main problem with jacketed bullet data substitution is COL. The ogive (the part that touches the rifling) is far closer to the point of a RN, for example, than it is for a FMJBT.
Using Sierra's COL's, the 150gr RN has a suggested COL of 3.000" (in .30-06, since that's what is being discussed.) But the 150gr FMJBT has a COL of 3.250".
If you develop a COL for your rifle for each bullet you reload, this won't be a problem. But if you use a COL for a bullet with a slimmer profile when seating a "stubby" bullet, you can unintentionally jam the bullet in the rifling.
And this "perfect storm" of dimensions won't happen every time. If it is grossly overlength, the round won't chamber. No problem. It is the combination of dimensions that just jams the bullet and permits the action to close...
Most manufacturer's COL's are designed to prevent this, for that particular bullet. And, unless your rifle has a short throat, things will be fine.
I'm aware your question didn't address all of this, but I believe it is a more complete answer...
Good luck.
Last edited by dmazur; Today at 01:32 AM. Reason: changed "wrong" to "overlength"
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