1) Original SIG 10 round mag
2) Plastic Black Dog 25 round mag
3) Plastic CMMG 25 round mag
4) Aluminium Black Dog 25 round mag
5) Plastic Black Dog 50 round drum mag
The aluminium mags are heavy, well built mags but they don't hold the bolt back on last round. The reason is that they have a shoulder that catches the ledge of the follower lower down and therefore the follower protrudes less from the aluminium mag than the plastic one.
If I put an original SIG mag follower in the aluminium Black Dog mag, then it sticks up enough to catch the bolt. See here the difference: the BD follower on the left and the SIG on the right:
And see here the difference when installed:
Here's what i know, from measuring all the followers:
1) The CMMG and the aluminium Black Dog mags both come with short followers.
2) The SIG mag comes with the long follower
3) I have one plastic Black Dog mag with a short follower. I don't know if they come with long followers at all
4) The drum mag follower is unique, it won't work in a straight magazine. However all the other followers are freely interchangeable amongst the mags.
My question is: who has these long followers? I need to get two for my aluminium mags (I have already swapped the follower from the SIG mag to one of my BD mags).
