Originally Posted by
oldsmellhound
I would guess a combination of problems. First, you are using pellets that are 7 years old. I would get rid of those right away. Pellets (especially if not stored in an airtight container) are notorious for sucking up moisture which then affects how well they shoot. It is very possible that you had a clean miss or two due to the old pellets. Switching over to a fresh can of loose powder will solve that issue.
It's also possible that you were not finding blood trails due to shot placement. Lung shots that are higher up tend to not bleed much right away, and sometimes don't bleed much at all. If you want to anchor the deer right away, go for a solid shoulder shot- you will probably ruin some meat this way, but most of the time the deer won't go anywhere. If you are confident in your marksmanship skills, a neck shot is another option.
Just because you don't find blood right away doesn't mean the deer wasn't hit mortally. Make sure you visually record the last place you see the deer as it is running away and the direction it is going. If you don't find blood right away, wait 30 minutes then go to the place you last saw the deer. Check for blood as you slowly follow the path it was taking. Eventually there should be at least a few small drops of blood here and there. Even if the bullet didn't expand, a .45 caliber slug through both lungs is going to kill the deer - you just need to find it.
I never use pellets of any kind so I have no input whatsoever on that.
I prefer to shoot the deer I shoot through the lungs whether it's with an arrow, a bullet from a center fire rifle, or a round ball or conical from one of my ML's. I have NEVER lost a deer I've shot through the lungs. Many go down within sight and others within hearing distance. Oldsmellhound is right, they may not begin to bleed for a short distance, but they will bleed and most rather quickly. If they don't bleed from the wound entrance or exit, they will begin to bleed from their nose and mouth as their lungs fill with blood they begin to cough it out as they attempt to breathe. So don't ever assume you missed because the deer doesn't readily go down.
On another note... oldsmellhound is also correct that a shoulder shot is best for anchoring them right away. It does make a mess to butcher and you'll lose some meat, but you won't spend any time tracking. Personally, I'd reserve the shoulder shots for any deer I don't want heading into a nasty thicket like multiflora rose or heading into a deep revene or maybe if it was a trophy buck I just didn't want going any farther than where I can see it, but I don't worry much about the deer going too far with a good punch through the lungs either.
BPS