Apologies forgot the smiley to indicate that it was supposed to be a joke, as you are using a car jack to "support" a rifle.
Of course nothing wrong with your approach and well done!
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Out of interest what was the small scissor jack from or was it a new one?
First saw them at my local F Class club back in the 90s. Some of them poorly made, tops wobbly, poor bases. Their scores reflected this.
The OP's base looks good compared to some.
Guys just got them cheap from wreckers.
Lots of the recycling centres and op shops have them as well.