I've used one of the little handheld spring loaded ones it was usless.
One year I had a broken arm that made using a knife difficult so I took my deer to processer. He had a electric one with rollers it worked fair. I haven't seen anything that works better than the mallet.
Another thing and I'm sure you know this. Any mature bucks get ground up completely. Once we get done buck hunting , we start laying down does and I like to take the yearlings. They get cut into steaks you can cut with a fork.
Sat on my big oat field last night counted 27 does out at one time. I never start taking does till later in the season though.
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