Plugs In Lower Receiver?

[ssc]

I was stripping an older (1996) Bushmaster lower. It had a JP trigger and speed hammer from around the late 90's installed. When I removed the grip, the screw had a couple of extra washers and I could tell it was short. 3/4 inch. I looked in the hole and could see a plug. It had a hex head and I removed it. Took another look and there was a second plug. I removed it. The first plug had a tapered end and the second one had a flat end. The grip hole is threaded all the way through. I have never seen this before and my recollection is this is not required to set up the JP trigger. My thought was that maybe someone had tried this "trick" to adjust the original stock trigger??? And perhaps whoever installed the JP trigger didn't notice this???

I was hoping with the collective expertise on this forum that someone might be able to inform me what this double plug situation represents. Frankly, I am just curious.

Thank you for your time, Steve

[lysander]

Shortening the draw of the trigger.

The set screw pushes the back of the trigger up and the sear nose down so there is less engagement with the hammer notch.

The second set screw was there to act as a lock-screw.

[ssc]

Thank you for the info.

Regards, Steve

[tehpwnag3]

The set screw in the grip screw hole may not have interfered with proper install of the JP, but it definitely wasn't needed since the JP has both take-up and over-travel adjustments. I would agree that the original owner probably tried to improve the feel of the stock trigger and then installed a JP later.