Question about PDI springs.

[HGI]

Ok I'm looking on WGC at these springs for TM shotguns....


I understand what the PDI 90 - 150 mean but what about when it says PDI0.8J or PDI0.9J??

This is one of these springs
http://www.wgcshop.com/pcart/shopper...S09J_srch_spas

[odp]

Those are approximate energy ratings.

0.8 Joules with a .2g bb is 293 fps
0.9 Joules with a .2g bb is 311 fps

Obviously there's no guarantee that you'll achieve those speeds, but it's probably a good guideline.

[HGI]

Ahh ok makes sence

Thanks.