According to Remington, the 7 has a 25 greater cup thickness and they state on their web site: "In rifle cartridges, the 6-1/2 small rifle primer should not be used in the 17 Remington, 222 Remington or the 223 Remington. Want to solder electrical wire or another electronic component to a piece of stainless steel? You can do it if you have the right flux, in this case.
In Winchester testing labs, primers are constantly and rigorously tested for consistency and sensitivity at temperatures and conditions far beyond the range of normal usage. 300 H&H 300 Savage 300 WSM 300 Whisper 300 Winchester Magnum 303 British 307 Winchester 308 Winchester 32 Auto 325 WSM 338 35 Remington 357 Magnum 375 H&H 38 Special 380 Auto 40 S&W 416 Rigby 44 Mag 444 Marlin 45 Auto 45 Colt 45-70 455 Webley. Fuel/oxidiser compounds are added to increase the eject gas temperature and volume for rapid and complete main-charge ignition.
