No 4 in 30.30

[browningautorifle]

That would be the biggest thing I think. I thought many times of doing a #4 or even a #1 up in 30-30. The forward lips are way out and would need sorting. The rim is smaller too...I wonder if you used a block at the rear to sit the cartridge forward, you'd need to alter the rear lips. Then the feed might be better, you can use pointed bullets too. I think it would be great.