I asked, "Messenger of Allah, what do you say if one of us catches game but has no knife with him, may he slaughter it with a sharp stone or a split stick?"He replied, "Make the blood flow with whatever you wish, and mention the name of Allah."
حدثنا موسى بن إسمعيل حدثنا حماد عن سماك بن حرب عن مري بن قطري
قلت يا رسول الله أرأيت إن أحدنا أصاب صيدا وليس معه سكين أيذبح بالمروة وشقة العصا فقال أمرر الدم بما شئت واذكر اسم الله عز وجل
Its isnad is hasan. Nasai narrated it in the chapter on Hunting, section titled "Hunting when the game has started to smell," Hadith 4309, from the hadith of Simak bin Harb through the same route, and Hakim graded it sahih according to the standard of Muslim, 4/24, and Dhahabi agreed with him.