I think the point is that the crime lab's conclusion that the gun was 24-30" away from the victim's head was due to allegedly faulty GSR testing - testing that would likely have been accurate had factory ammo been used in the gun.
Bias told the investigators the revolver had been loaded with extra-light handloads.
During the grand jury inquest, the following exchange came with a senior investigator on the stand:
Prosecutor: "In fact, the uh, the rounds that were uh, taken that night and the rounds that were tested were rounds that Mr. Bias himself had reloaded, is that correct?"
Sergeant: "Yes, that's correct."
However, the test ammunition taken from the Bias home (not from the gun) and submitted to the crime lab for examination included cartridges with R-P headstamps. The loads in the gun, and in the box it was loaded from, were all in Federal +P cases.
Apparently, the handloads taken for testing were full power loads, NOT the light handloads Bias claimed were in the gun. The tested loads deposited visible gunshot residue until a distance of 50" was reached. Factory Federal 158-grain lead semi-wadcutter +P would leave visible GSR at that distance or greater.
No particulate matter, sooting, tattooing, or other evidence of GSR of any kind had been found on the victim's hair, head or clothing. The medical examiner took pains to measure the dead woman's arm's reach, and determined approximately 30" for that measurement. The investigators and experts were unanimous at the trial: she could not have shot herself without leaving gunshot residue.
However,
With duplicate loads in an exemplar six-inch Smith, Ayoob and Co. determined the light 2.3 grain Bullseye load with the 115-grain bullet would deposit GSR to perhaps three feet. At that distance, it left only about a dozen loose particles. At 24" there was still only loose particles, and even at 20" the powder would still be in very loose particles, with virtually nothing embedded.
Due to this testing and the realities of time, blood, etc., they concluded it was entirely possible Bias was telling the truth and the gun had been in his wife's hand when it discharged, and there were well-established reasons why no GSR might have been found on the body when the totality of the circumstances were considered.
I'm not saying he was innocent, just that if he was telling the truth, and had factory ammo been in the gun, the GSR would have been consistent with his story. I would want it to be consistent with my story, for sure - and I don't want to be the name on the next case y’all are discussing!
Also, let's not forget that we (at least I) should be unconcerned with saving $20 on ammo that's honestly no better than factory, when it could result in the possibility of this even being an issue in court, because if it's an issue, and even if we win, the defense of that point will cost you far, far more than you saved.