So I'm looking at getting some straight mags for my CA94. I can get SD marked for $3.00 more per mag is this worth the money? I'm guessing they are the same HK made but not designated as military issued? I'm just wondering if down the road they may be worth the difference if I ever sell or if they may dry up and be more desirable to collectors / enthusiasts? or save the $3.00 and no biggie??

I say save the $3.00

I have a bunch of both. The MP5-SD was created in 74 (well it began its life then) and all of my straight mags that are dated before then have no SD nomenclature. All the 74 or newer ones have SD stamped on them.  I can't see any difference between the them. At one time, I heard that the SD models had a quiter follower so that it wouldn't make a noise when it got hit by the bolt carrier. But I've taken them apart and they all seem to be the same to me.

I prefer the curved mags for my SD though because they reportedly feed hollow points better.

I'd save the $3. Unless you want one just for shits and giggles. I bought a lot of 15 mags, and there was 4-5 of them SD marked, but it wasn't anything special past that.

I have several and they all work great. I've never ran HP ammo in them. All but 1 are marked SD. What are you paying for them? I would part w/ mine for $25 each. my email is [email protected]