lets go ahead and get the legal crapola out of the way..
this is for educational purposes only. if you attempt the herein information then you agree to be bound by the terms outlined below. if you do not agree then do not attempt. you do so at your own risk.
me (the author), and castboolits, and all people associated with listed and unlisted shall not be held liable for any damages incurred by trying the herein contained information. any damages, death, injury, disfiguration, loss of limb or bodily functions, or destruction of property is the sole responsibility of the person or persons who try the information set forth in this video.. any damages or injuries incurred, listed or unlisted, shall be the sole responsibility of whomever decides to try the contain information. by going forward with using this information you agree to be bound by said terms above.
ok. down to business.. https://www.youtube.com/watch?v=q8KmWCTWCEo
now we get to the fun stuff of improvisation.. this is a tutorial (sort of), on how to use small pistol primers in large rifle cases. this information is for a emergency situation only, like if you cannot get large rifle primers anymore (like in a post collapse environment) and should not be the sole means of priming cartridges. with this system, if you can find any type of ammo or component then you can make ammo for your rifle. your rifle may or may not be able to set off this primer adaptation, so it is best to test one b4 putting powder in the case or trying a lot. it is also worth noting that in some rare cases the primer does stick out just a hair when seated. this may or may not cause problems with semi automatic rifles or bolt guns with super tight head space..
the military bolt actions, especially the Mauser, has no problems with this. i have even done this in my SKS with good results.. it even set off the H414 spherical ball powder .308 load that i made... but i use this method a lot in my cast bullet loads using pistol powder and have never had a malfunction.
im not sure how it changes the pressures, if it does at all, but as always, start at the lowest setting of published data and work up.. always follow the instructions in the manuals.