whats the difference between these two?
Mass, alloy, precise shape, and possibly overall quality?
Had the exact same question come up a few weeks ago and they did not seem to be the same pellet. The Destroyers have been very accurate in almost every pistol or rifle we have. The Destroyer EX have not been tried yet in all the a.g. so will withhold judgement on them, but grossly they seem to shoot at least OK in some of the a.g. However they did not appear to be exactly the same pellet on closer inspection.
Here is a very interesting post 3 APR 2010 in the old GTA Bargain Gate (now archives), complete with pictures: http://www.gatewaytoairguns.com/airguns/index.php/topic,25845.0.html
I have a bunch of Destroyers; Medic has a bunch of Destroyer EX. Just now quickly tossed a few of the Destroyers on the scale and they are a hair under 8.0 gr; for the moment say 7.9+ or 8.0- I will check a bit more accurately tonight and ask Medic to bring over some EX so we're using the same scale.
Summary of what the GTA post showed:
Destroyer 250 / tin 8.0 gr well formed probably pure lead
Destroyer EX 7.4 gr 300 / tin odd die marks compared to originals probably lead alloy.
Some alleged differences in group sizes but there are so many variables on that, I'd be cautious making a decision based on a couple of experiences because YMMV.