What's the difference between Midsouth's Varmint Nightmare & Nightmare Xtreme?

[jasonprox700]

Does anybody know the difference between Midsouth's Varmint Nightmare and Nightmare Xtreme?  It seems the standard nightmare has a cannelure, higher BC, and is $4 less.
 
I will be using these in a 1:9 twist .223 and 1:12 twist .22-250 on paper, steel, and prairie dogs.

[LaOtto222]

It have only used MidSouth's Nightmare Extreme in 34 and 50 grain varieties. BTW - I have had very good accuracy with both in 1 - 14" twist barrels shooting them in 22 Hornet, 22K Hornet and 223 rifles. I am guessing the difference is the jacket thickness uniformity. Remember, I said guessing. Why would a bullet that has an extra step (cannilure) in it cost less? I sure would like to know who makes them for MidSouth

Good Luck and Good Shooting

[PowPow]

I also thought the difference was jacket thickness (still a guess), simliar to Hornaday SP and SPSX.
I have used the 55 VNE's in a 1:14 22-250 with H380 with pretty good results (albeit not THE best results for my gun).
Only on paper though.