Good afternoon Dwayne,
All seems to be going great in BC for you.
Like you, I'm always looking for the Holy Grail of rimfire accuracy without costing an arm and a leg.
Hence the reason CCI of any sort is not in my ammo box. Recently because of all the hoopla over how
well it shoots I bought some CCI SV to try out again. Unfortunately my rifles showed it to be mediocre, ie Minute of Berm.
A while back I decided to shoot a 50 rd box at a target just to see how well they would do. My first mistake was centering on the
bullseye and after 10 rounds I had to guess at the center. I ended up shooting 45 rounds but I can't remember if they were RWS Subsonic or
Norma Subsonic. The rifle was a Kimber HS in a Varmint stock with a 6X scope. That target is below.

[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]

On another day when proving a point to someone, I cleaned the barrel of a custom Rem. and a Sako Quad. I shot 5 rounds per target of Wolf MT and compared the 2 rifles. The Sako was wearing an 8-24 scope and the Rem. a 6X. That scope power of course was the issue. Like the target above, these were shot at 50yds.
Below is that target. This type of grouping is what I expect out of my rimfires at 50yds. Anything other than that is not of any interest to me.

[Linked Image from i.imgur.com]

So I certainly understand your chasing the elusive 10 rounds in a ragged hole at 50yds...............with a repeater, and I should add, a Sporter weight.