Hmmm, I would certainly worry about a LP primer in a LR primer pocket as it would sit extra deep and S&W revolvers, especially those with frame mount firing pins are notoriously short.
Unlike small pistol/small rifle primers which have the same exterior physical dimensions, large pistol primers are shorter than large rifle primers.
Could work — or could give misfires.
Do you seriously think I'd recommend doing something that I hadn't done extensively & had confidence in??
There is .008" in height difference, listed in the SAAMI specs, for LPP & LRPs.
In my past checks primer pocket depths themselves vary widely, even between the same brand/caliber brass.
Yes, I'm sure it could make a difference for someone in some revolver but I've done this extensively in my reduced 460 & 500 Magnum handloads & have never had a FTF due to an insufficient primer strike.
And while light strikes have been commonly reported (& I've experienced) in certain revolvers, notably N-frame 45ACP & 10AUTOs, which have their own set of unique circumstances that can contribute to that, I don't recall seeing such complaints about X-frame revolvers.
Certainly I've not experienced it & in looking in my personal database I see my 500ES's firing pin measures only .4835".
If that firing pin was in any of my 45ACP or 10AUTO revolvers it would surely have caused problems & have been replaced as they commonly need a firing pin .490" or longer to fire reliably, especially when firing without moonclips, & I usually prefer the firing pin be closer to .500" in these models.
Frame mounted firing pins are cheap & easily replaced if that's what needs to done.
And while these reduced loads are still powerful they're intended for range use, not as self-defense loads though they sure could fulfill that, such ammo would need thorough testing before being used as such.
As in anything new, make a small batch & test them in your revolver before loading them in bulk.
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