Different RT On/offs?

[BiNumber3]

Quick question, I just noticed that I have 2 slightly different RT on/offs

1 has an o-ring groove on top (where it would contact the quad o-ring or similar)
and my other 2 don't

So, is there a difference between the 2? maybe one shouldn't be used without quad o-rings or something?

[ScreamingShiek]

Quad oring on/offs are for Emags, regular on/offs are for RT mags.

[reckid1986]

is one a ULT? or maybe someone modded one at one time for some reason

[BiNumber3]

Looks pretty clean if it was a mod. So is the groove there for quad o-rings? should I not use the on/off with the groove on anything other than an emag?

[athomas]

The only one that has an oring groove, is the ULT. If its not the ULT, then it is some aftermarket or modified part. Its not an emag part. Can you take a picture of it?

[BiNumber3]

Here ya go, it's not a ULT tho as the pin is still an RT pin (iirc the ULT pin's aren't compatible with RT on/offs):

<a href="http://i33.photobucket.com/albums/d74/BiNumber3/P1000543.jpg"><img src="http://i33.photobucket.com/albums/d74/BiNumber3/P1000543.jpg" width="600" height="450"></img></a>

[reckid1986]

looks like somebody modified it, no idea why though.

[athomas]

Hmmm, It looks like a modified retro on-off. It would make the oring sit farther down on the pin which would simulate a longer pin. I can't imagine that it worked well for anyone, unless they were using a short emag pin with a standard urethane oring in a gun that had a worn sear. It would have uncontrollable runaway shooting unless they could force a longer timing distance between when the on-off closed and the sear released the bolt.