Good way to know if the Piston seal fit is good?

[byhsu]

Yes, the Seal did fit tight.  As for the Sleeve, I redid how it was attached, originally there were tabs folding out that were hooked at the opening of the piston, so they were impeding the steel sleeve from expanding when the spring was fitted, so it was tight.  I polished the spring and also I made a new sleeve with tabs that folded in and were placed at the bottom of the sleeve and they were retained by a metal washer (3/4") with 3/8" opening, so now the spring fits in perfect.

I no longer feel the piston slamming into the internals of the rifle when I fire, I was getting that with the old piston seal because it was fitting too loosely and it would slide down with gravity, this new piston seal won't slide down with gravity, I have to push it in. 

Firing cycle is very nice now, and It is more accurate, even with the Cheap Crosman Premier Hollow Points.

[Bayman]

Yes, the Seal did fit tight.  As for the Sleeve, I redid how it was attached, originally there were tabs folding out that were hooked at the opening of the piston, so they were impeding the steel sleeve from expanding when the spring was fitted, so it was tight.  I polished the spring and also I made a new sleeve with tabs that folded in and were placed at the bottom of the sleeve and they were retained by a metal washer (3/4") with 3/8" opening, so now the spring fits in perfect.

I no longer feel the piston slamming into the internals of the rifle when I fire, I was getting that with the old piston seal because it was fitting too loosely and it would slide down with gravity, this new piston seal won't slide down with gravity, I have to push it in. 

Firing cycle is very nice now, and It is more accurate, even with the Cheap Crosman Premier Hollow Points.

Excellent. Good news. POI steady now?

[byhsu]

Yes, pretty much, I will test it again this coming weekend when I get a chance.  Thanks for the recommendation on Vortek Seals, I like the cup style and that they fit a little more snug, the OEM seal on mine was undersized.