Great rifle. My first inline was the same 700 54cal. SS. I stiill use it, more than any of the other ML's I own and I do have a 700 in 50cal.
My 54 I shot for many years with just the #11 niple useing CCI mag caps with T7 loose powder.
I switched to the 209 system and was told it is Canadain from Qu.
Check with gander mountian or bass pro shop.
The 54.
The 50.
The 54cal of mine loves 100gr. T7 purple MMP sabots and 50cal. 300gr HP Speer Gold Dots.
You will want to get one of these for taking the bolt apart for cleaning.
I got it at Gander mountian for $10.00.
Al