Ned Ludd
Silver $$ Contributor
I've had pretty good luck seating the 80.5s at .012" off the lands in .223 Rem. Unfortunately, there is no guarantee that seating depths that have worked for myself or anyone else responding to this thread will be optimal in your specific setup. I would suggest testing the 80.5s at seating depths from .003" off to .030" off in .003 " increments. I'd be very surprised if you didn't find an optimal seating depth window within that range.
However, if that somehow does not provide the precision you're after, I would then go back and try seating them from "touching" to .009" into the lands, again using .003" increments. I'd rather not have to seat a bullet into the lands unless it's absolutely necessary (i.e. it won't shoot anywhere else), especially a tangent ogive design like the 80.5 Fullbore bullet. Nonetheless, it is not uncommon for .224 heavy bullets to tune in from around .003" to .007" or so into the lands if they don't seem to want to shoot jumped (off the lands). Some of the downside(s) to seating bullets into the lands include that the optimal window may be much narrower than for jumped bullets, the initial pressure spike may be increased, you may have issues dumping powder into the action if you ever need to open the bolt and extract an unfired round, and you may need to "chase the lands" pretty rigorously in order to maintain peak precision.
With respect to your question about whether 24.5 gr Varget is too much powder, no one here can answer that question definitively without a lot more information about your load and specific setup. You obviously chose the 24.5 gr charge weight, so what made you decide on that specific charge weight? My point is that I'm assuming you must have previously had a good reason to believe that 24.5 gr was an optimized charge weight. Has anything changed that would alter your opinion on that? If yes, then you should probably be starting from scratch with a new load development. Piecemeal selection of charge weight and/or seating depth is not a good approach. It requires a LOT of luck to work, and luck is not something we should really ever need or count on during the load development process. A well-structured and rigorous incremental approach to the reloading process is usually more than sufficient to identify a stable load that shoots well. In fact, I would consider it the exception rather than the rule when such an approach fails to deliver. My point is that if you're unsure whether your charge weight is optimal, then it probably isn't. Starting over with the load development won't hurt anything, and may ultimately provide better results than simply trying to find a better seating depth optimum using what might be a sub-optimal charge weight. If you're not sure whether the charge weight is optimnal, fix that issue first. Then do your due diligence with seating depth and you ought to end up with a load that shoots very well.
