Terminus Apollo action ,small firing pin 6mm Creedmoor

[Ironworker]

What is the purpose of the extra small diameter firing pin on my custom Terminus action ? I bought some Federal factory 6mm Creedmoor ammo. Opening the box,it was small rifle primer ! I heard I might get poor ignition in winter conditions ? Had to try it out in NV desert today,30 degrees ,I had zero problems,in fact it shot very well,under 1/2 MOA .

 

[Evan]

More brass surrounding the primer means you can run more pressure before the case head expands. Same story for your small firing pin - less unsupported primer to extrude into the pin hole in the bolt and possibly pierce, which allows you to again run higher pressure before hitting problems. Some of those fantastic speeds and nuclear loads you see on the internet are, in fact, extremely high pressure that far exceed the rated maximum. Small firing pin, small primer, and hard brass allow for it to happen.

 

[RegionRat]

Not all powders will give ignition problems in colder weather, but some ball powders will.