On the latest mission of the Lady G two of my gunners shared a kill on a EA. I gave them each a possible 1/2 credit for the kill. After the mission the Lady G only received 1/2 credit over all for the kill, so does each gunner receive 1/4 credit for the kill. I'm thinking yes but not sure. Thanks for any help.
If I understand your question, I believe yor are misapplying option rule 7.6.2 for resolving kill claims.
In this case, when two gunners fire on the same enemy figher and it goes down, regardles the results each gunner rolled individually, both gunners record a CLAIM for one kill each.
After the mission, you would roll on table 7-6 FOR EACH GUNNER, and award them kills based on the results. It is thus possible for a single shot down fighter to result in anywhere between 0 and 2 kills for the crew overall.
A little strange when you get more than one kill per fighter shot down, but as the long explaination in 7.6.1 points out, awarding kills was a morale issue, as much as anything, so it's not really supposed to be mathematically correct.