Here is one way to add a cool 68% force to your gas system: The original gas piston is 0.550 dia. You can fit up to 0.712 dia trough the RSB with very minimal Dremel touch up.
This will give you a force increase of about 68%. I will send you pictures of the M77 adjustable gas bushing on Monday. A bushing like that could be used to couple a larger gas tube to the existing gas block.
Do not weaken the spring. You may need that force to get through the forward feeding and locking stroke reliably.