Guys before you get real wound up with the tar and feathers and the big lengthy safety speeches. I would suggest you compare the saami spec pressures of the two cartridges the OP asked about, and a few things like the 41 and 44 mags, 480 ruger,454 casull and 500 S&W.
I'll also point out that using large pistol primers in the big bpcr cartridges is pretty common practice.
Yeeeep!!
When I was actively competing on our local High Power matches I fired a bare MINIMUM of 100 rounds per month, assuming NO load development and NO practicing, which was extremely rare. Every single one of these cartridges, light cast bullet loads, were loaded with LPP's. Never a single misfire after firing cumulatively around 3000 LPP's in 7.5x55's and 30-06's.
The subject of primer height came up in a thread earlier this year and rather than answer via rectal extraction (that'd be an uneducated guess), I measured some of my primers. Here's what I came up with from primers I have on hand:
Pistol:
Fed. 150 & 155- .120"
CCI-300- .122"
CCI-350- .118"
WLP- .120"
Rifle:
WLR- .127"
CCI-200 & 250- .124"
Real world difference, about .005" or about the thickness of a piece of printer paper. Maximum difference: about .009" or about the thickness of two pieces of printer paper. If either of these differences causes misfires in a rifle, it ain't the primers fault!
Would I as a matter of habit load LPP's in rifle cases for full-power loads? No, but I darn sure wouldn't let it stop me from shooting if it were all I had!
My son several years ago aquired a large amount of mostly military primed 223/556x45 cases. I have just got around to testing proven handloads in said primed cases.In almost every case using the same lot of powder,I am getting flattened primers firing them im my M 11 Savage.I have suspected that since the only variable is the primers,perhaps I am dealing with pistol primers.Anyone have any thoughts on that?The package deal he bought was from a person who was getting out of loading and included a press,dies,thousands of assorted primers and around 2000 of the primed cases in 223 Remington.I need to load some loads with known good CCI SRP and see if I still get flattened primers
Flattened primers do not universally mean high pressures as they can be caused by many different things. The absolute worst case of flattened primers I have ever seen was in my fathers 35 Whelen. New Remington cases had shoulders set back too far which of course created a headspace problem. Upon firing the primrs would flatten horribly.
So, your flattened primers could be caused by high pressure loads or from someone who full-length sized the cases and set the shoulders back too far .
35W