Okay I have a problem I've never had before. Hornady has a load for the 6.5x52 Carcano that uses WLRM primers. I have FLRM primers on hand. I have never substituted a different brand (primer) before so l don't know what to do to start loading. Do I start at the lowest powder load like always or in the middle or where ?
One of the problems with primers is that many manufacturers dink around with them. As I noted in one of my GUN GACK books, there have been at least three versions of the CCI 450, their small-rifle magnum primer, since it was introduced in the 1960s. The first just had a thicker cup, to withstand the higher pressures of newer cartridges, but the amount of priming compound was the same as in the CCI 400 "non-magnum" primer. The next version used more of the same priming compound, but in the early 1990's CCI switched to a hotter compound--and at the same time also started using the hotter compound in their large-rifle magnum primer, the CCI 250.
All of which is yet another reason I tend to rely far more on chronographs than "pressure signs." If muzzle velocity is in the ball-park listed by various manuals, then pressure probably is as well.
Of course, one problem with the 6.5x52 Carcano is there aren't many data sources anymore.
I am guessing the load you're working with is one of those listed for the 160-grain Hornady round-nose bullet--which is the only bullet they used the WLRM for. All their other Carcano data uses the standard WLR. I don't know the reason for that, or their warning: "Only Winchester WLRM primers should be used with this data." You might contact Hornady and ask--especially since these days it's hard to find ANY primers, much less the "correct" primer for such a specific load.
