Sap Piston

[Impulse]

Has anyone got experience with it? I'm waiting on mine to arrive and I was wondering if I have to put one of the weighted sleeves on or if I can just leave it as is without any weights. With a rapax 2J spring in my build at the moment with the SCW piston, I'm pulling 2.3J on .45s so I'm worried if I put a weighty piston in it will creep over the limit.

Has anyone run one of these and if so has anyone run it without using any of the weights? I just don't want to damage it as soon as I get it!

 

[Skara]

What's wrong with the SCW one?

 

[Impulse]

What's wrong with the SCW one?

Noisy, even with the airbrake and all my attempts to further silence it. Want to try the SAP as I've heard it in action in a guy's rifle that he did very little else to and was suitably impressed.

I guess this is what I get for using a HPA VSR. Everything is loud by comparison!

 

[Skara]

I guess this is what I get for using a HPA VSR. Everything is loud by comparison!

Yup that is your problem

In my quest for silencing the striker, everyone always suggested "go HPA" which is a dumb advice honestly. I mean, if I were to go HPA I'd just get a MTW and call it a day.

/OT

I guess you already tried to add some weight to the SCW piston to slow it down (compensating for the creep with a softer spring)

The only experience I have with SAP pistons, unfortunately, is just forum/facebook posts about how shit it is for the striker's standard cylinder

 

[alxndrhll]

I can only speak for the SRS one but it's a lovely bit of kit. So much to move around to tune it exactly as you like, the threaded airbrake is a very intelligent move. Swapping out the weighted sleeves is super easy, the only real thing to be cautious of is the lube you're using on/around the buffer/dampening ring. It's advised to not use anything with silicon in it because that ring will absorb it which will eventually cause it to swell and need to be swapped out (my SRS one came with a spare, can't speak for the VSR one). Though I do suspect if you're on the hunt to try and make a VSR running a spring as quiet as HPA you're going to be sorely disappointed.

Cheers,
Alex

 

[Skara]

I think you're right.

I just installed the SCW piston and it's noticeably louder than the stock plastic one on my T-11 ?

 

[alxndrhll]

Out of curiosity what was the design of the original piston? Cup style or ring style?

It may purely be coincidence but I’ve tended to find that the ‘cup’ style pistons (stock SRS, WASP and SAP) are generally quieter than the ‘ring’ style pistons (stock Marui, SCW etc etc).

My best guess is the cup design natively generates less of a ‘slap’ against the cylinder head, but that could be entirely anecdotal. As for air brakes, I can’t say I’ve ever found them making much if any difference when it comes to sound. I’ve found them useful for tuning FPS and that’s about it (which is why I think the SAP has the best one, because it being threaded means any changes are reversible). 

 

[Skara]

The original is a ring style just like the SCW, but with a concave head (I'll upload a picture tomorrow of both pistons, but I'll do it in my T-11 thread to keep this one free from unrelated messages).

Also yep, by design they seem to be quieter (huge rubber pad impacting the cylinder head rather than bare metal/small o-ring).