Large vs small primers for 450BM. PP vs RP?

[Enfielder]

I bought some mixed once fired brass and all of the Hornady cases have large pockets. The rest (Starline, Winchester, Federal Etc.) have small pockets. At 38,500 PSI it seems like I could run LPP or SPP since 454 Casull runs at 65,000psi with a SRP. I know that is assumption and the statement is a bit of a stretch with lots of info missing. That’s why I’m here asking……
I guess the real question here is what are the max pressures for pistol primers and minimums for rifle primers?

 

[mcb]

It would probably work with pistol primers but the rifle primers are often a touch hotter than regular pistol primers of the same size. Lots of powder in that 450 BM and the rifle primers (and Magnum pistol) primers might get you more consistent and reliable ignition. All my brass is small primer and I have had good luck with Winchester small rifle primers. I am not that hard up for rifle primers yet...

 

[reddog81]

There's typically a lot of powder in a 450 BM load. For the small primer brass I'd stick with rifle primers or at least magnum pistol primers under the assumption they will do a better job igniting all the powder.

Is the larger primer brass meant for LPP or LRP?

 

[Cheesemaker]

Most pressures I have seen in loading data (LPP) has the pistol primers max'ing out around of 35k-36k PSI (not CUP)i. I have no idea if this is a "real" limit or not.

Personally, I would favor rifle primers (large or small) over pistol if the pressures are exceeding 35k PSI. Not for (possibly) any ignition benefits, purely a pressure handling benefit.

 

[Enfielder]

There's typically a lot of powder in a 450 BM load. For the small primer brass I'd stick with rifle primers or at least magnum pistol primers under the assumption they will do a better job igniting all the powder.

Is the larger primer brass meant for LPP or LRP?

I don’t know the answer to that. I’d have to contact Hornady for that info. The Saami spec for 450 shows a small rifle primer since ( I’m guessing) it’s meant for AR bolt face tolerances. 0.473 case head

 

[Enfielder]

I have this big old box of LPP I’d like to burn up.……
40grains of H110 under a 250FTX. it might be a pressure limit for the primer…