Hey stevenf,
I just recently got a Belltec and have had only one chance to use it in rocky conditions. I hadn’t yet adjusted the hydraulic relief pressure, but it sure did work nice. That was in Williamson County – a couple of hours north of you and almost as rocky. I need to dig some holes about 30 miles outside of Boerne at my sister’s ranch, so I know it will get a good workout there.
For t-post in rocky areas, I’ve been using a pneumatic rock drill with a 100CFM Ingersol Rand portable compressor. The rock drill is a 35 pounder and I use a 1 3/8” x 2’ drill steel on it. It makes a nice pilot hole and I still have to use a hand held t-post driver which I like because the post ends up firmly planted in the ground.
The reason I mention this is you must have the 2” puff drill that they sell for the Belltec. I’ve wondered if it didn’t leave too big of a hole for the t-post to be firmly planted? I would like to hear your opinion on this as due to the cost, there aren’t too many Belltec owners around. I only have the 9” RAD auger.