The new guns use a stamped piece of spring steel instead of the machined part of the old ones, but either can have the tension reduced by thinning the rear "leg" with a hand grinder (Dremel tool) and a sanding drum. Run the drum over the inside of the spring part, taking care not to thin the part where the screw enters. Use long passes and cool the part in water after each pass to keep it from getting hot. The new stamped part should take only a few passes to reduce tension.
Warning - don't thin the spring in just one place or it will break, and don't thin it too much as some tension is needed. Also make sure to polish down any burrs and sharp edges as they often catch on the cartridge and make loading difficult.
Jim
