Consider this calculator https://www.engineersedge.com/calcul...l_pres_pop.htm
If you use the following values you can get an idea of the safety of a gas through grip
P = 1800 psi (The burst rating on a CO2 safety)
R = 0.25" (this means the passage is 1/2" diameter, which is considerably larger than most gas through grips)
S = 14000 psi (this is using the WRONG, but lowest number from MatWeb for 6061 aluminium
E = .80 (80% joint efficiency)
This yields a resulting wall thickness of 0.0445"
Most gas through grips are around 3/8" dia passage, and 3/4" or larger outside diameter... Running those numbers... with a wall thickness of 0.1875" and an OD of 0.75", the result is 7000 psi.
Personally, I like to down rate things... No need to expose yourself to unnecessary risks, so assume 50% and you still have 3500 psi with a 2x safety rating (My engineer friends can chime in and point out that this is not enough, according to the industry, if this is the case.)