[M4 Magazine Extension; need new magazine spring?]

Thanks DAdams! Appreciate your help.

[M4 Magazine Extension; need new magazine spring?]

In interest of reliability, is anyone using or offering for sale a longer magazine spring to work with the extended magazines on the M4? Is it necessary?

 

I'm having feeding problems with a brand new M4 and am wondering if it may be that the magazine spring is too weak after installing a magazine extension.

 

Any help or comments would be most appreciated.

 

Thanks!