I posted this in your other thread too.
We had a brand new rifle built with one and it failed after about 30 rounds. On one instance I was shooting a group and it would not release, I imediatly lifted the bolt handle and it fired upon bolt lift. Supposably, I got cleaning fluid in it while doing the barrel break in and that caused a problem. We sent it in and Jewell wanted $25 to repair it. They said it was dirty and failed from years of "Wear and Tear". When we informed them it was new, they sent us a new one right out no charge. Ironically, a freind had one fail a few weeks after that from dirt. It is my belief that the tiggers with a very light pull ( under 1 1/2#) have parts that rely on very close tolerances for them to move. Even the smallest amount of dust or cleaning solution in the wrong place can make them fail. I have since decided that on a rifle I hunt with I will stick with the triggers that do not go under 1 1/2 pounds. I believe they have a more reliable mechanism and I set them at 1 1/2 lb and all has been good.
Hope this helps.
I will add that I had an almost identical problem with another manufacturers trigger. This was a new custom rifle
that had never been to the range and it failed. It to was dropping the pin upon bolt lift too. I took it out of the stock and found that the highly recommended smith had installed a USED trigger that would not adjust above one pound. Not the 1 1/2 to 3 lb I had requested and picked out of his book.
So in conclusion, I think this is a probelm with the triggers designed to go under a pound and not just Jewells.
and yes, Jewell recommended we use lighter fluid to clean them and also recommended we remover the trigger every time we cleaned the barrel to keep solution and oil out of it. They said to clean the trigger each time we had it off with lighter fluid.