I checked the rounds that were left after the 5th week, and they all still had a puddle of oil on them, except for the rounds with WD-40 on them.

It was still there, but some of it had evaporated, as expected.

So, I re-applied it to those rounds.

Here's a picture to show the puddles.

Week Six:
Today, we fired the remaining rounds (5 each) of each type of oil.

I decided to do a little practice on double taps, just to avoid wasting the ammo.

All 30 rounds fired just fine.

Lessons learned:
1. Was this test "fair"? No, absolutely not.

It was about ten times more severe than any normal situation, where oil might come into casual contact with a cartridge. No one puddles oil on the primers of their ammunition for 6 weeks at a time. This test was a Worse Case Scenario.

Might different ammunition and different oils react differently than those in this test? Yes, that is possible.

2. Will casual oil likely invade and "kill" primers in cartridges? No. This rumor is greatly exaggerated.

3. Is it possible that in some case, under special circumstances, that oil might kill a primer in loaded ammo? Maybe. But it would have to be a worse scenario than this one.

4. Should we then just get oil all over our ammunition? No, of course not. There is no need to court disaster. I will continue to keep my ammunition as dry as possible.

But I won't be paranoid about it any more.

And shooting stuff is fun.

And there you have it, boys. Another myth busted.