mickb wrote:mate again it isnt just about pressures, its whether the pistol primer can light up a rifle charge twice as heavy. The brisance of pistol primers is a lot lower than rifles.
I have heard of cast bullet folks using large pistol primers in their rifles but only using pistol powders aka reduced loads off stuff like unique and alliant etc
Also again, the large pistol primer is short for the rifle pocket, it will sit recessed which also I assume mean it may set back under firing as its not supported by the bolt face. Again, not sure what effect this has in real life, but I assume its not ideal to have a primer backing out at high speed. But getting back to the first point I think lighting up the rifle charge is going to be the main drama anyway. Magnum large pistol primers may have more chance..
It's a possibility. Best way to find out would be to try it. Might be an issue with very slow rifle powders. The slowest powder ADI suggest for the .444 is AR2208, it seems to prefer the faster powders, and especially pistol/shotshell powders. If APS950 is here to stay, and supply is good then that might be the answer. It's a little faster than the old AR2205 so I would imagine pistol shooters are already testing it in a variety of pistol chamberings.
Primers are supposed to be recessed, these will just be a little further recessed. It might be an issue if you have a short striker perhaps.
Bottom line is, if you can't get large rifle primers try large pistol ones, just don't try to push them up to full-noise rifle pressures.