After a long plane ride, we had two different Encore's that would consistently not fire the first time the trigger was pulled. You could see where the firing pin had struck the primer but not enough to set it off. After the guns were cocked again and fired it would go off. After being fired quite a bit we had less and less trouble with them not going off on the first trigger pull.
Both frames are two years old and never had this problem until out hunting trip. Any ideas on what the cause was or a solution so that it will not happen again.

On his web site, Mike Bellm claims that the hammer springs, as they come from the factory, are a bit weak. His trigger job, includes replacement of the factory springs with stronger ones.

Besides something being wrong with the gun, there could be a problem with the ammunition or primers though with this happening in two different guns, it wouldn't seem likely. Specifically, military primers are harder and may need a bit more force to detonate. Some say CCI primers are harder but I've never had a problem with them. A rimless bottlenecked case that was sized excessively or a rimless straight walled cartridge that was crimped excessively could cause headspace to be excessive and interfere with primer detonation as well.

He also said that if you have a hammer extention you need a 55 lb hammer spring to make up the weight of the hammer extention.

Used to have that problem, especially with rimless cases, now I FL size with shellholder maybe 1/2 turn off to cause a slight bump at case neck where cartridge should headspace on. Cartridge now fully supported front and rear and should fire......r in s.

I think Ray is right on. Make sure your frame is closing tight. Also check th firing pin. My neighbor had one that was pitted on the end, casuing light hit, esp with hammer extension.

Sounds like a headspace problem to me also.
As to them going off after you shot it a bit, fouling more than likley help hold the cas back where it belonged.

What remains a mystery though is that both guns functioned without flaw for two years and then after a plane ride both guns had the same problem.

I had the same problem and called T/C it was my hammer extension if you have one on your gun try that