Moly infused piston seals?

It will only make a difference if your lubricant fails, and even then as a last ditch effort to prevent friction. 

It's just moly filled urethane, but with no mention of how much, it could be so little it wouldn't matter anyway. 

I've never found any practical advantage to them over other makers urethane seals. They are good seals and well made, but don't expect them to do anything a red or blue one couldn't do. They both still need lube to work right. 
 
Thumper is right. Don't neglect proper lubrication. I've tried multiple seal types from all the popular suppliers. I have found the Vortek seals are the best blend of power and durability. They make the make much more power than the Weihrauch factory seals.

The Vortek seals initially fit very tight. So much so it was concerning to me. I sized the seals as I have the other popular seals. I gained a fair amount of velocity by sizing the Vortek seals only to find it was completely unnecessary.

Vortek seals will feel ridiculously tight when installing them. Don't sweat it. They will fire form and loosen up in a hundred or two shots.. You'll pick up 40 fps + from your first few shots. I use them in all my builds. They will produce more power than popular competitors without any alteration.

You can pick whatever tuning kit or process you want but I can tell you the Vortek piston seal is the way to top it. I make very few hard line statements. This one I'll stand on. 
 
Thumper is right. Don't neglect proper lubrication. I've tried multiple seal types from all the popular suppliers. I have found the Vortek seals are the best blend of power and durability. They make the make much more power than the Weihrauch factory seals.

The Vortek seals initially fit very tight. So much so it was concerning to me. I sized the seals as I have the other popular seals. I gained a fair amount of velocity by sizing the Vortek seals only to find it was completely unnecessary.

Vortek seals will feel ridiculously tight when installing them. Don't sweat it. They will fire form and loosen up in a hundred or two shots.. You'll pick up 40 fps + from your first few shots. I use them in all my builds. They will produce more power than popular competitors without any alteration.

You can pick whatever tuning kit or process you want but I can tell you the Vortek piston seal is the way to top it. I make very few hard line statements. This one I'll stand on.

So what exactly do you suppose is happening during the "fire forming" process? 

And why does it not happen with other makers seals? 

After all, they can't be "wearing in" because the moly is there to explicitly prevent that, right? 

If it forms or wears or self-fits or whatever, what keeps this from continuing to the point of becoming too loose? 
 
Thumper is right. Don't neglect proper lubrication. I've tried multiple seal types from all the popular suppliers. I have found the Vortek seals are the best blend of power and durability. They make the make much more power than the Weihrauch factory seals.

The Vortek seals initially fit very tight. So much so it was concerning to me. I sized the seals as I have the other popular seals. I gained a fair amount of velocity by sizing the Vortek seals only to find it was completely unnecessary.

Vortek seals will feel ridiculously tight when installing them. Don't sweat it. They will fire form and loosen up in a hundred or two shots.. You'll pick up 40 fps + from your first few shots. I use them in all my builds. They will produce more power than popular competitors without any alteration.

You can pick whatever tuning kit or process you want but I can tell you the Vortek piston seal is the way to top it. I make very few hard line statements. This one I'll stand on.

So what exactly do you suppose is happening during the "fire forming" process? 

And why does it not happen with other makers seals? 

After all, they can't be "wearing in" because the moly is there to explicitly prevent that, right? 

If it forms or wears or self-fits or whatever, what keeps this from continuing to the point of becoming too loose?

I can't say exactly why. I can say it does. I've used all the popular seals at least as far as Weihrauchs are concerned. Other guns I can't vouch for. I've put lots of Weihrauchs together with various seals. The Vortek seals always go in tight. Very tight sometimes. If I have to disassemble a gun shortly after initial install for whatever reason they're always much looser than going in. I'm not sure why. I think it's the material. Compressing air creates heat, which I believe sizes the piston seal after some cycles. I think other seals may use more urethane or silicone and are less changed by compression heat.

All my guns and ones I've done for others have Vortek seals in them. I'm not sure anybody I've done a gun for has worn out a Vortek piston seal yet. If so I haven't heard of it yet. I have them in all of my guns (Weihrauchs). I can easily get 10k shots out of them. Fall 2020 I finally replaced the seal in my Hw95 when the extreme spread stepped over 12 and my POI was wandering. I installed that seal in December 2015 and I'm sure had well over 10k shots on it. Wouldn't surprise me if it had twice that. 

They just work. I liken it to gravity. When I'm high off the ground, I don't have to know why gravity works. I only have to know that it does. After a while the evidence is clear and the reasoning doesn't matter. To each their own this is my experience.

Edit- "I can easily get 10k shots out of them". Well that provided there's nothing wrong with the compression tube finish, theres proper lubrication and they aren't dry fired.

Also I believe what keeps them from becoming too small is the flared cup design. The cup causes the air pressure to exert outward force and each cycle works the keep the seal fitted. Similar to a parachute seal with less outward force.

Be well

Ron