Exactly. Interesting note on work hardening;
Penn Stainless inventory now includes Alloy 420 (UNS S42000) in sheet, sheet coil, plate, round bar, processed flat bar and tubular products.
www.pennstainless.com
Therefore they fully anneal the cap and then draw it through progressive dies to make the closed-ended tube. This work-hardens the material as you progress through the die sets. Copper is a great example of work-hardening where repeated bending of wire eventually breaks it.
What I like about the hotter caps is that they do an excellent job of directing heat to the center of the load. These caps make combustion much easier but not along the chamber walls. More often than not, combustion is a coal in the very center of the load. Removing the cap just before ignition prevents the load from combusting. The density of the vape is so much thicker than anything I do on regular daily sessions with lesser caps. They require a little more diligence. Alas, this unique performance hasn't been matched with offerings in recent years.
My experience - gain-ratio measurements - IH current with the VC divided by IH current without the VC 4A over 1A for instance... is a 4:1 GR cap
I have 6.0, 6.2, and 6.0 caps as my hottest. They all have DYn-nnnn serial numbers.
5:1 is my '18 VapCap - no serial number
4:1 are several early and late '19 caps & my original C-Vap logo'd DD cap. Either external serial numbers or inside digger. This includes a '19 PhantoM.
3.x non-captive caps are from the parts department at Dynavap. Daily drivers.
2.high-x was my 2020 cap.
4:1 caps are comfortable. They rarely combust and they provide good heat and a solid draw without dipping to get a full set of lungs.
6:1 caps are a treat but require attention. Almost like drinking your vape. Some strains can be too much even for the best iron-lungs out there.