[ark-and-spark]

Whats the best way to smash this rivet without a plinker jig?

 

[Kalashnikox]

You can use a bucking bar held in a vise. Put the bar in the vise, support it where you can and rivet away. It would help if you did that one before the top one.

 

[DWarner]

I usually just weld it in with my wire feed. No problems, so far.

 

[Tapeo1]

Are you talking about the long rivet on the UF? If so, then Kalashnikox's method works for me. If you talking about the small rivet at the bottom of the UF rear trunnion, then you can modify 24" bolt cutters to reach those lower rivets.