This is a replacement trigger guard for Airsoft M4's.
I made this for mine to work as a spacer to push the back of the magazine forward, so the magazine would mesh with the hopup better.
For your application, either measure the required distance and edit the model or file/sand away material from the front until your magazines fit perfectly.
Electrical tape cushions are for suckers.
Tested to be functional with a Cyma M4 using Elite Force 140rd magazines. The forward end of the trigger guard would need to be extended further forward for my Echo 1 BAMF STANAG magazine and my A&K metal midcap magazine. As the EF mags are the best bang-for-buck and most common midcaps I see on the field, I'm happy with the results.
any PLA, ABS & PETG
May require sanding/fitting, but didn't on my M4. You will need a second roller pin just like the one in your trigger guard now for the front pin slot - and it will need to be trimmed so it doesn't protrude too much.
Something to be aware of is that if the magazine fit is TOO tight, the forward edge of the trigger guard will eventually wear down, possibly to the point of needing a replacement.