Piston advice please

[Hangtight]

Right, I've got a couple of pistons laying around and I need one for a mildly stressed build (M100, 170mm barrel, around 20rps). Do I go for the full metal rack that had holes hacked in it by the previous owner and that I made a bit neater when I was bored...

Before

View attachment 22236

After...

View attachment 22237

Or the bog standard, single metal tooth JG one stood next to it.

 

[Sitting Duck]

Might need a m110 for a shorter 170mm barrel

Use what piston fits and works....

Which one fits in not too loose/wobbly but doesn't bind

Also check at full retraction which one may not "bottom out"

some pistons at full retraction can hit back of box

Are the heads still on the pistons ???

check compression whilst you are at it - at least suss which piston head & o-ring gives best compression

Might have replace self tap screw with M3 bolt - maybe on cheap heads they go through the head & tighten up inside

so you might need a m3 nut washer etc... with threadlock or nylon locking nut

Any of them have that mofo chunky metal spring spacer in piston ?

F*cking dump that pile of crap if possible they weigh about 7 or 8 grams - that is a LOT

the metal chunk is about 9mm thick so that can be replaced with a 5 or 10mm plastic spacer-much lighter

The issue is - by the time you f*ck about trying to put together something that ticks every box possible

you wonder is it worth f*cking about just for a basic piston ffs

well maybe not all the OCD crap unless you are really sad like me - but was more for possible pointers

Use the one that works the best - hopefully without the chunky metal crap inside

Swiss cheese pistons at best you will lose about 10 to 15% of the piston's weight unless you go really nuts

(risk of weakening if you go too mad near the rack)

if you keep the metal chunky bit then what is the point of any swiss stuff

also the bare piston will be about 12gms or 13gms - so what you save 2gms and I find the white cheapo pistons

these are quite damn tough for what they are and take a bit more cleaning up to remove all the strands from swissing

In other words - dump the spacer or replace with something lighter - a 10mm spacer will be about 1.2gms

so you save more weight by using that than swiss cheese

you could probably get a basic cheapo piston at 15-16gms complete & metal rack one at about 22-25gms

weight or swiss means little - it what works best - no bind or too loose wobbly fitting

doesn't run risk of bottoming out at rear of box, decent pick up tooth and good compression in final use

Soz too much waffle- just what one works best with the least hassle/work is my short answer

 

[PopRocket123]

Don't suggest anything ocd inducing to him. He gets so anal about these things it's amazing he's not gay

 

[Sitting Duck]

nowt wrong with a bit of OCD unless it gets out of hand....

 

[Hangtight]

So rude! Youth of today... mutter, grump, bah!

I don't have to fix and tune your Airsoft guns you know son. Just for that you can wear a nice big, colourful "Shoot me" sign next skirmish.

 

[Hangtight]

They've both got cylinder heads, and as they stand both weigh 24.3g complete. The Swiss cheese one seems to be a glass reinforced nylon, full metal rack with the second tooth absent (by design) and the third one ground entirely off by the previous owner. I only ever take off as much tooth as required to just clear the sector gear, but I think this one should just pick up the fourth tooth without breaking the sector. It also has a bearing fitted. I was concerned that I'd taken too much material out for it to be robust enough, but I left as much as possible by the rack.

The Jing Gong one is bone stock.

In over thinking it again. Flip coin, put one in. If it doesn't break, it was the right choice. Carry the other one as a spare. If I have to fit that then order a new SHS one just in case...

I'll add a M110 to the list. Don't Krytac PDWs have around a 170mm barrel? What spring do they come with and what fps as standard?

 

[ImTriggerHappy]

Try the ICS or Lonex pistons over SHS. SHS are a bit cheaper but I find the other two a bit cheaper. The older ICS 8 hole silent piston and the reinforced pom ones are still my go to for most things. I wouldn't use a full metal rack in most guns though because all AEG's need a point of failure and the piston is the cheapest.

 

[Sitting Duck]

What ever works best - what ever you feel might operate more effectively

personally I like to leave the runners intact especially if on some v2's having a rear window

on G&G's or a couple of others that are solid like most v3's

no rear window I will use if possible the swiss shs one:

on others I like to leave the piston guides/runners intact in case it might wobble a bit on last 3 teeth

where it passes the rear window and swiss my own if I can be ar$ed....

That was a heavy mofo piston in the HC05

but some people go way way too nutz imho

 

Sorry but THIS is WAY WAY OTT - and besides seems like a part metal SHS one

Somebody went got the dremel out and got way way too carried away I think

different piston's bottoming out can happen at rear of some boxes with some pistons

often they might look at bit close but in reality/use the highest tension point of spring

will ensure they fire the very second the last tooth slips off sector

BUT it can bottom out if using full stroke or pistons with just one last final tooth

Usually very rare but if building from bits n bobs or MadBull Alien pistons were supposed to be a bit long in the tooth/length department I saw somebody once say...

often I may Short Stroke a tooth or two so this doesn't matter (3+metal teeth, last one must be metal)

but if using a stock one with just one metal final tooth then perhaps give a quick once over to be sure etc...

Agree with Trigger, need a weak point to avoid full on damage if she jams

But also owners need a sprinkling of common sense too....

How many times have we seen a new player's gun jam and then they proceed to full auto even dry firing to clear

std lame gun it might not be too risky but whack the juice up or motor to 20rps and risks greatly increase...

ZZZzzzzz - yeah m8, you got a jam and that was slowing the piston firing so THAT was why it all smashed up on auto

Are you sure ???

YES m8, coz I have done that myself a few times

NEXT TIME - get the jamming rod out instead and ease up on the trigger a sec

Still can happen I know - but think we have all done some "OOooh $hit - that don't sound right" moments

Just hopefully now we are a tiny tiny tiny bit more wiser than our first outing with our peew peew peew's