Weird on/off design and body mod

[Alexndl]

Got this on/off in a bundle purchase

Any idea who made it and if its worth using?
Unknown on/ogg on the left standard AGD on the right with onl style on/off top
20210927_163156.jpg 20210927_163208.jpg

Blue top is thicker than standard top
Pin is thinner
Seem to be missing oring on both side of the on off but its not the standard one (maybe 003?)
Tried assembling it but the pin does not fit well with the blue top (not sure they go together)


In the same bundle was this AGD body with a hole added on the top
Any info if this mod is usefull/would damage or be inefficient?
Anyone see it done on a body?
20210929_163203.jpg

[BrickHaus]

I keep coming back to see if someone answered this. Not yet.

I dont know why the body is that way, but Id consider making a homebrew meech hopper with it. Put a roller into that slot and let the bolt shoulder actuate your hopper every shot!

[Spider!]

I've heard of the body window thing. It was a "cool" thing.

It doesn't affect function, other than dirt and water intrusion.

Given the velocity behavior of mags with different return springs, I would expect some changes from anything touching the bolt. If you put anything in there, make light and consistent.

[Alexndl]

Ok, never knew it was a common mod... I could use a sight rail to block the hole and cover it if needed

[Alexndl]

Any info on the weird on/off?

[Alexndl]

Nobody?

the thin on off pin does not seem to go with any if the on off top I have
the on off body is not as long as regular on offn seem like it could work with the blue on off top but the hole is too small to pass the top of the pin...