What does this bit do????

[38Super]

The main problem with 10 in a mag is difficulty inserting on a closed bolt. When I started I had mostly the older 'round' end springs which I think are stiffer.
The latest mag I've got has the 'square' ended spring which is better.

I'll have to find (or make) some shorter buckshot rounds then.

I had loads of trouble at the weekend with some homemade slug that seemed to be very tight in my gun causing the action to be a bit slow, not closing properly and light strikes. They were a bit long at 2.4" LOA (usual diet is Power Blue 2.25" LOA) but about .010" fatter. Same problems as the buckshot (also 10 thou fatter than PB).
I'm wondering if my chamber is just a bit tight.

[Blackstuff]

Have you seen this video, might be worth a try;

https://www.youtube.com/watch?v=JiOIkGEVcnA&t=0s

[38Super]

Yes I have seen it. Wish I'd seen it 3 years ago. I took the option of sanding my followers in the tight mags instead. I could go down to Shield and borrow their mag 'tool'. Got to go there anyway to try out the muzzle brake.

Not sure I'm having the same issue though as my mags run 100% with Power Blue and S&B slug. The issue looks ammo related rather than mag related.