Look at the fps rating at both the guns. FPS stands for feet per second, which ever one has more fps has more fire power. But be warded, sniper rifles are mostly spring, which means you have to cock them. Machine gun airsoft guns (AEG's) are electric. If its rpm, go for an electric, but be warned...lots of websites lie about the guns real fps so lots of times the gun will go in real life 373 fps when the website says it goes 400. Make sure to do alot of research before making a purchase, and read lots of reviews.
All airsoft can jam. Phrase your question better. Such as Does blowback airsoft jam more than spring airsoft?
Airsoft gi is a lot better. There website is way better, and there store is like 3 or 4 times bigger.
they both have the same firepower
M41 is not a standard airsoft model, did you mean a different one. Also it depends who makes them.
Yes. All you need to do is take disassemble your airsoft, take out the spring, and buy a newer, better one. I reccomend all airsoft at Evike.com.
As a general rule, you get what you pay for.
The M4 CARBINE IS BETTER THAN THE M16.
Better is a relative term. A sniper and an AEG are for two completely different gaming styles. The choice is a matter of personal preference and the specifics of the games you play.