I've had a similar problem with my M7 caused by the ejector shaving brass from the cartridge case head. The shavings eventually lodge inside the ejector hole causing it to get stuck. I've polished the face of the ejector where it rubs against the case head as well as the ejector hole to reduce the brass shaving. Played with trimming the spring to reduce the ejection force but finally decided to reinstall a full power spring. I've come to the conclusion that my problem is most likely too little headspace which causes the case to jam or stick and not rotate when closing the bolt. With the polishing the brass shaving is reduced. May need to bump the shoulder back more on my reloads and try that first. It's always confusing when these things happen. Not a professional gunsmith but you know how that goes.
Remington couldn't fix it when I gave them the first try. They are a do it yourself proposition unfortunately.
More likely you run handloads on the very hot side...
The case is bigger after firing, therefore the bigger problem comes during ejection, not loading.
The idea of reducing spring force because the ejection is weak is backward.