While waiting on hold to RA my super-bolt back for the Foamy upgrade I was thinking about the intermittent reports that even some of the boiled SBs are still breaking.
If delrin doesn't work out, I guess other materials will be considered. I know titanium is out due to expense, and I think I remember Tom saying that the weight difference between aluminum and stainless wasn't enough to make the project viable - so I was brainstorming. What about a severely fluted aluminum sleeve that can slipped on the bolt and held in place with set screws? The entire body of the sleeve could be fluted to the max, while leaving a circular face on the end to stop blow back. The aluminum would wear over time, but since it would be removable, could be replaced.
Potential problems, the retention set screws backing out and gouging the inside of the body. (Especially the new Extremes) This could be rectified with lock-tite; even the red to be especially sure of no loosening. Since the bolt is all metal there would no problem with heating it to remove the screws when it is time to change sleeves.
Second problem (related to the first) the retention screws loosening and the sleeve being fired from the gun. I'm sure decent retention system could be engineered to avoid this - but it would be a concern.
What do you guys think?