I just got my new to me Schultz and Larsen in the mail today. I bought one that was advertised as "the bolt would not close" and needed repair. Thanks to the posts in this thread I knew that I could adjust the headspace to make it work. When I stripped the bolt I found a .038" thick spacer between the bolt lock and the bolt body. When I assembled it without the spacer it was too loose. I found a steel washer that was .025" thick and close to the other dimensions of the spacer. By using my dremel to open the hole in the washer from .400" to .435" I made it fit and stoned the burrs off. The washer is smaller on the outer dimension .630" vs .660" and fits fine. I checked the headspace of the bolt by using a feeler gauge between the receiver and the rear of the bolt lock block without the firing pin spring in place. With the .025" spacer I can close the bolt with resistance on a 0.0015" feeler gauge. It closes freely without the gauge. I think that I will not get it any better than that. This whole process took less than two hours. I think that someone must have stripped several of the rifles and mixed up the headspace spacers, I remember someone in this thread that had cases "ballooning" and he must have been missing or had the wrong spacer.
By the way, my bolt stop is not like the others I have seen here. Instead of a hex head screw to keep the bolt from rising to the final removal notch in the reciever I have a spring loaded plunger. This makes it easy when inserting the bolt as I just push ahead to compress the plunger and lower the bolt. Looking forward to shooting this beauty.
270 totheend