Using a standard shotgun primer isn't what i consider as 'taking a chance', when they work 100% of the time for a year, then another, and then yet another.......................... Standard primer have ignited BH in the TC rifle, as long as BH has been available. Easily hundreds and hundreds of shots. Once the plug were modified in the CVA rifle, standard shotgun primer have ignited BH without a delay, thousands of times. These rifle have been tested in conditions no sane hunter would endure.

In my Knight rifles, no magnum primer fits as nicely as W209 primer. It is near mandatory to use W209 in them rifle. In the TC rifle here, nothing fits better than W209 primer. The CVA rifles and breech plug, in this house, are adjusted to use STS primer, and them magnum primer won't fit.

Using standard shotgun primer, is not 'taking a chance'.

'Taking a chance' is passing a snow plow in a storm, driving after drinking, writing a check with insufficient funds, adding air to a slow leaking tire, telling a fib, purchasing a lottery ticket....................

If one cannot find magnum primer locally; one needn't worry needlessly; they are not needed.