The Ashcroft Frequencies is an urban myth that has arisen in recent times of a set of 'cursed' frequencies to which the beam of a swap rifle may be calibrated. As the rumors go, these frequencies were locked out by software patches and hardware updates implemented by shadow government agencies after researchers found that it allowed the beam to slip outside of our mundane reality, intersecting with entities that dwell within realms of existence parallel-yet-invisible to our own.

It should be stated straight off the bat how dangerously untrue this legend is. Swap rifles are highly controlled for good reason - they are dangerous tools even when used responsibly and when the myriad built-in safeguards (there to ensure a user doesn't accidentally insert their mind into an airborne microbe) are functioning correctly. Enabling the frequencies requires most of those safeguards to be circumvented. Thankfully the overlap in the Venn diagram of individuals intelligent enough to make such technical modifications and stupid enough to actually perform them is minimal. That being said, a number of genuinely modified devices are in circulation along with a great many fakes.

A small subculture of self-named 'psychonauts' have taken to using these devices and documenting their out-of-body experiences online. Their reports are wild and fanciful, with claims that they have exchanged minds with the disembodied souls of the deceased, with aliens, with alternative versions of themselves, with angels and demons and self-transforming fractal machine elves.

Their methodology is crude. Working in pairs, they visit areas of particular 'spiritual' significance, and then use a modified rifle to repeatedly trade bodies with their partner until the beam (which forms the psychoelectric ego-bridge by which the neural energy is exchanged) hits 'something' on the 'other side'. It is then the duty of their partner to wrestle the being inhabiting their body into reactivating the rifle to bring the psychonaut back from wherever they find themselves.

The sheer amount of cumulative brain damage received from thousands of rapid-fire bodyswaps may go a long way to explaining the fantastical stories these people return with. Numerous of these foolhardy individuals have already 'lost' themselves in this process, their minds blasted from their heads, many undoubtedly now trapped in some wretched vessel, be that insectoid or ameboid (though certainly not machine-elven), and beyond our ability to locate or identify them; or mercifully deceased.

The government has gone to lengths to confiscate any modified rifle it can and clamp down on the psychonaut subculture, though they continue, with many enjoying a following on social media.