Double trouble, a cautionary tale.

[HisSoldier]

My 1970's Mauser had what I considered to be too heavy a trigger, 6.9 pounds. I read much of what was said here about fixing it, plus Henriot's Ebook, and finally bought a 1974 Shooting times magazine that told how to work on it. He said to take the sear ledge on the firing pin down .015-.020". I decided to go slow and took it down .010". I did the other things too including reset and over travel screws to the the trigger.
I was very happy when I found it was 4.5 pounds, but when I shot it I took the careful man's method, load only one extra round. Sure as heck, it doubled. I shoot through a baffle box so my neighbors won't have to listen to the boom.

When I shot it it happened so fast I foolishly assumed both rounds were in the target, I got up to walk downrange to look but saw a splintered hole in the top of the baffle box! The second round went up at a 35 degree angle, through the top of the box and through the roof! I hate to think what a full magazine would have done!
Anyway, I've fixed the problem, it wasn't the .010" I took off, it was a bad angle on the sear lever. I rehoned it and now it works, still 4.5 pounds.

But, there is a better way to test than loading only two rounds, in my later tests I loaded one live round and below it a snap cap, after shooting the first round a "click" on the second pull tells me that the sear/firing pin is still under pressure. Had I done that before there wouldn't be a hole in the roof of my shop.