Good and bad

[activsean]

I just received 2000 friendswood 155 grain 40 cal boolits from powder valley. I loaded up 100 or so with 5.2 grains of bullseye and took them to the range. The good was that I was shooting inch or less groups at 10 yards and 2-3 inch groups at 20 yards out of my sig 226. The most accurate that I have shot. The bad was that I had 3 rounds out of the hundred that failed to go into battery in the sig. The gun has about 8000 rounds through it. Prior to this, I have always shot or loaded 180 grain boolits in the gun and have never had one single burp from the gun.
Is the spring going bad or am I loading too light???

 

[Certaindeaf]

It well could be too light but I doubt it. If the load locks the slide back, it should be strong enough/full power enough to chamber a good round.
I think your chamber/throat might be a little tight/short and or some of those slugs/case combo are just too wide to seat.
Make sure to do the "plunk test" with your removed barrel. Good luck