[T. O'Heir]

"...how I can fix it..." Depends on how bad the crack is. If the stock cracked from just falling over, the wood is likely very dry.
If you can open the crack a wee bit, go buy one of the needle style epoxy applicators and use that. Then put on a couple of padded clamps.
"...surgical tubing, very tight electrical tape, or inner tube..." None of which will ever be tight enough.