This could evolve into the new primer saga. :-)
I used hockey tape, one layer on the set. Drove dozens before replacing.
My experience was that if I drove toward a solid surface, it was hard to control the process. If I drove toward 'free air', it was hard to control the process. What worked for me was to place the work on either something like a moving blanket, or (better) a sheet of something like 1/2" thick carpet underpad. For me, the work needed to move just enough to 'bounce' the bar away from the shop head, without moving enough in-line or laterally to let the set come off the head.
If I had to rivet toward 'air', I'd use as many free fingers as I could spare to push back on the work (not the bar or rivet) so the work couldn't move much. This, with as much hand pressure on the gun as I could manage & still control everything, helped to keep the set on the factory head.
No claim that all mine were perfect, but the above is what worked best for me.
Charlie
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