>SKS
>not easy
The magazine springs are usually rather soft, and the bolt locks open on the clip. To remove the clip you should be able to just flick it with a finger or thumb from behind, which causes the bolt to drop and shoot it forward out and away from the action. What difficulty are you having, in particular?
To answer your question proper, I've found that FAL and L1A1 clip cut dust covers tend to be pretty smooth and easy to use, and the FAL action in general is rather slick and has lots of room to stick your fingers without worrying about hurting them. If you want something even more comfortable than that, the Vz. 58/CZ 858 is nothing more than a modified SKS action turned into a modern combat rifle, and accordingly, the bolt functions in the same manner and they are compatible with SKS stripper clips. Due to the triangular shape of the bolt, how wide the receiver is, and how cleanly the bolt operates and handles when clip feeding, I'd say the Vz. 58 is probably one of the nicest rifles designed for a commonly used type of clip.
Bonuses are that the Vz. 58 is legal in many places where AKs are banned, it's an extremely simple and reliable gun with an even easier field strip than an AK, its action is extremely easy to clear due to how much space the breech gives you (while also keeping tolerances that avoid debris getting in), and the fact that it's a gun that takes both detachable mags and stripper clips means you can carry spares of each, giving you your choice of loading options that can make a big difference depending on the situation. In some cases a clip may be faster, or if you run totally out of ammo, all you have to do is lock the bolt open and feed the clips directly into the magazine - frankly, it's such a stupid simple and neat design that I'm amazed no country ever did anything similar (except for units that adopted clip cut FALs, which would mainly include Canadian C1A1s in terms of standard issue rifles).