BM winning chances

Well, I know that black market is definitely about luck.
One can win a weapon from a single crate other can't get it even with 300 crates.
But as far as i also know there are some weapons that are actually classified as "rare" or with a low winning chances.
My question is which one of those two weapons has a higher winning chance with 20 crates ( as i only have 20k ep)
1-M4a1 Patriot.
2-M14EBR.
Thanks in advance.

Comments