Grizz Mag Spring Power???

[Beaner1976]

I just recently purchased a S&J follower and 870 police mag spring for my 12.5Grizzly. The police spring was much longer then the factory spring so I ended up shortening it to around 19 inches. I snipped short pieces off at a time and tryed it out until I found what I figured to be a good pressure (just pushing up on the follower and feeling the resistance with my finger). It has more push now and the spring itself is beefier. But my question is, how much power is to much? If I left it longer will the resistance in the tube be to great and cause issues(damage shells, break shell stop, or slam out the shell to hard). Is there some kind of rule of thumb to judging proper mag spring strength. I went hunting today and the gun cycled flawlessly but Im just curious if anyone has any insight.

 

[CanAm]

Too much power is when it becomes difficult to load the last rd into the tube. If it is really bad you could cause excess wear on the latches, but the loading would be really tough then.