I believe the bomb materials, at least the one which was planted on Hitler's plane, and failed to explode, were from captured british SAS material.

Some of the reported attempts on Hitler's life were hopelessly inept, and never had a chance of success. Von Stauffenberg's was at least well planned, but he surely could have used a better bomb.

From what I have read, they were not even close to producing a usable atomic weapon, in part due to the fact that they chose "heavy water" as the moderating medium, where we chose a much more convenient graphite medium.

One account claims that deception helped influence this decision.