Pinned mag

[Muffin]

I just got my 10 KA metal lowcaps(68rnd) in today. I recall hearing from others that you can somehow mod them to only house a certain amount of rounds. I'd like to change these all to 30rnd mags without having to count each one.
Is there such a way to make this possible without causing feeding issues?

[Styrak]

EDIT: Wrong advice. Here's the right advice, I forgot:

Do not move the lower plunger or spring. Just put a screw with a big enough diameter through the BB channel and through the spring, so that BB's stop at that point and the spring cannot slip past.

[Muffin]

So then just leave the spring where it is then? Or do you put more coils in the area where the rounds will be fed? I just want to make sure that it'll have enough force to avoid any missfeeding issues.

[Styrak]

Oopsies actually I forgot, I gae the wrong advice: do not move the lower plunger or spring. Just put a screw with a big enough diameter through the BB channel and through the spring, so that BB's stop at that point and the spring cannot slip past.
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