This is simple laws of physics. A one ounce lead weight compared to a 5 ounce lead weight moving at roughly the same feet per second. The 5 oz. lead weight will have more stored energy because of its weight, there for it will penetrate deeper. All store bought 30-06 bullets are going to have roughly the same powder charge regardless of bullet weight. the 150 gr. bullet will have a bit flatter trajectory than a 180 gr. bullet and it will also have more velocity because it takes less energy to move a lighter weight bullet. With this being said, there are plus and minuses to each bullet. The 150 gr. will give you better shot placement at distances of 200 yards and beyond because it flies flatter to the target. Because this bullet weighs less it will be impacted more by obstacles in the path of flight. At close ranges in thick cover, a heavier bullet is best. This bullet can hit a leaf, blade of grass, bone and even a small twig without it effecting its flight enough to matter. A smaller bullet will deflect greatly with any obstructions at all. With that said, none of them will shoot through a sizable obstruction and still hit a target and any of them will kill deer with the right shot placement. If I hunt heavy cover where I know I will not get a shot at more than 50 to 75 yards, I go with a heavy bullet. This also applies to arrow weights too. The heavier the arrow, the better the penetration.
I have shot deer at close ranges with a .270 140 gr. bullet through both lungs and they still ran over 500 yards. The bullet is moving so fast at the time of impact that it has very little time to expand. Alot of times it will leave the same size hole coming out as it made going in. This is where a heavier bullet makes up the difference.
I have another question about Close-up shooting with a 30-06 or a .270 WSM Rifle,guess it doesn't matter too much on the caliber but more on where to aim on a Deer thats very close (say around 10-25 yards away)?I sight my Rifles out to 100 yards dead-on the target I don't sight them at 1 or 2 inches high like most reccomend since like most on here I usually have Deer come in anywhere from 50-75 yards away all though I have shot several Deer out to around 100-125 yards at the most so far,for me I just haven't had the opportunity to shoot a Deer 200 plus yards away and probably wouldn't push that far a shot anyways?
So what I'm trying to say is if You sight your Rifle out at 100 yards and a Deer runs up on You at a close range do you aim high or low on their bodies vital area?Sounds silly but I've never sighted my Rifle's out to 100 yards then took a shot at close range? [&:] [8|]
Most of the time you can just hold on center. The bullet isn't going to rise or fall all that much. But, to answer your question, on most big game cartridges you would hold high on a close shot if you centered your rifle in at 100 yards. The reason for this is, the bullet actually drops before it starts to rise. It is kinda like a well hit drive of a golf ball. If you watch it close enough, you will see it actually drop some before it starts to get some loft. This is the reason most golf tees are built on mounds and not level with the fairway. If you sight your rifle in at 100 yards, chances are it hasn't even started to drop yet. At 125 yards or so, it may even be a little high. At 50 yards it will be around an inch or so low. I have shot the same rifle now for over 15 years. It is a 7MM Mag and I know how it shoots from 10 yards to over 500 yards. I have all the confidence in the world with this gun. Generally, where I hunt, if I can see it, I can kill it!