Can you over-tension a mag?

[PineTar]

Cut and crammed a wolf spring for stock P220 into a Mec-Gar 220 Mag. Do I need to worry about over-tension issues or anything?

 

[Gammon]

Just cut the spring to a length that allows the top round to be depressed when the fully loaded mag is inserted into the pistol with the slide in battery. The mag should enter the mag well and engage the mag release without too much effort. Too long a mag spring can make the fully loaded mag difficult to seat with the slide in battery. Also the excess pressure caused by an overly long mag spring can cause the top round to drag on the slide which might produce a malfunction. Mag springs are relatively cheap; cut one down until you get the results you want. If you screw up you can always try another spring.

 

[winter]

I run a G26 10rd mag with 11 rounds.. No adverse effects.. Not ever.