OP- Rem 742/740's had a history of jamming- the few I have were magazine related issues, something to check. A rem 760 purchased in 1975 has had a jam at the bench secondary to a faulty mag. It has never failed in the field.
6 hrs seems like a minimal amount of time to search- but I do not know, the weather, time constraints, area that you are searching. I understand that you never want to lose an animal.
WISDOM OF THE DAY- I double lunged a huge buck @ 15 yds with the bow many years ago. Massive blood trail, snow on the ground, last day of archery in Mi. I went into the house, changed and began looking. Massive blood, it went 75-80 yds then stopped!! No tracks leading from the blood, NO BLOOD, luminol confirmed. This was Jan 1, I finally found the deer March 29 after the snow receded. I learned that when the blood STOPS, start backtracking. I found the headless carcass, about 3 yds off the trail behind a blowdown, 40 yds back from where the blood stopped. I had been angry a my self for losing it, for 3 months. The animal will be consumed by the woods, and I learned a valuable, albeit painful lesson.
Someone asked why a functioning pump instead of a bolt- 5 shots quickly when shooting 5 animals, you may be good with a bolt, but not as fast as a pump. Accuracy is 1 moa, better with a better operator, with factory 30-06 180 gr PSP core-loct.
Jmorrison: I have shot over 200 whitetails and one "required" a second shot because it was going to cross off my property. It was dead on it's feet, 1" cube of heart was a site of first shot. I am curious as to what caliber/bullet you are using? I have found that deer shot under 50 yds- run, not far but still run. When I did crop damage I would prefer all shots to be 200 + yds, they would just drop. Shot 6 with the pistol 44 mag at 33 yards- all ran, all were recovered, Ammo was rem, fed,pmc,win, imi 240 the farthest went 90 yards. All were double lung with varying cardiac damage. I have switched to 240 XTP, they no longer run, with same heart lung shot.
The first shot is the most important one. Good Luck. Be Safe,