Regardless of the temperature for efficiency and consistency you want to be using the smallest amount of gas possible to propel the BB at your desired FPS and reliably cycle the system ready for the next shot.
What does this come down to?
Air seals, Friction and Weight of dynamic parts, Work effort and Stability of materials in different temperatures.
Air seals;
Gas tight mag obv.
Healthy gas route seal in mag.
Mating fully with nozzle entry.
Nozzle fully sealed in bucking.
Air tight bucking.
Floating valve closing fast and sealing.
Piston lid seal that reacts fast, but doesn’t drag.
BCG turning off the gas knocker, properly in time - not too early or late.
Friction - freely moving, minimal contact, not side loading;
Floating valve.
Nozzle.
Bolt.
Buffer.
Buffer spring.
Weight of dynamic parts;
Lightest nozzle, bolt, buffer.
Work effort;
A bucking that is too tight will hold the nozzle firmly requiring more effort to pull it out.
A nozzle that isn’t free in the bolt or BBU will do the same.
A piston lid seal that is too big or binding will also increase effort.
A bolt that is poorly made will side load the receiver or buffer tube
@Wild Weasel.
Increased weight of dynamic parts.
Stronger buffer springs.
Materials like nylon etc have massive dimensional changes for small temperature changes, materials like these are best avoided.
As a general rule all parts ‘flowing’ gas should be of high quality plastics to maintain the intended dimensions and best resist the effects of icing.
Pretty much everything above could be broken down further.
The short fix is the stock TM design is very good.
Non of the buffer parts need to be ‘upgraded’, the buffer is very light in TM plastic, and the spring is suitable for all UK assault FPS (300-350).
Yes fit a lightweight CNC bolt, the UAC ones are a nice fit.
The stock nozzle and piston lid seal are fine, as is the stock bucking (within reason).
Yes fit an NPAS or similar, plastic please, mod the TM one ideally.
PS sorry you didn’t get around to actually doing your testing!
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