I'm liking the look of that case of "Ball" ctgs., Caprivi. As long as the ball is full sized or several of full sized balls, they'd be fun.
That is a NICE little gun.

I just measured the muzzle of my Brazillion Single shot .410 that shoots so well with both 2 1/2" and the .444 Marlin cases with 1/2 ounce + trimmed off WW .410 wad and 12gr. Unique with crimped G/C. and it's .400".