How do I attach a high capacity magazine to a weapon

[GmanUK1965]

I have a high capacity magazine that is compatible with weapon but cannot figure out how to attach it. I read on internet that it can be attached by pressing T and highlighting upgrade so it shows as orange but it doesn't turn orange. It also states that it can be done in inventory by selecting it and placing it on weapon but it doesn't work

[inotna2001]

1. Equip the weapon
2. Drag and drop attachment to weapon, or right click the attachment and select the weapon from the menu.
3. To remove attachment, right click on weapon and click remove attachments.

[Bad Distraction Carnifex]

Drag+drop on the applicable weapon from within the inventory screen. If it's a unique weapon that slot may be taken up already by something else. You can later detach any non-default accessories by clicking the same menu that gives you the drop, drop all, etc options.

[NIKKE Reference]

If you are in an area where you can have your weapon out in your hands, you can also hold T to do it and get a little animation too.

[whispa]

if you equip the gun and drag and drop the mag on the weapon it should fit to the gun, that's what i did.

[GmanUK1965]

It is Valik Lummox's AKM-74S maybe that's the reason

[drkstorm1]

Note to controller players: Been playing on pc with controller. It was impossible to drag the mag over to the weapon and equip. I had to use the mouse then it went on easily.