Here's my reply from our PM, so it can also help other shooters also.
Ok. COAL and OAL are the same thing- Cartridge Overall Length= COAL or OAL=overall length. Your COAL or OAL on the round pictured is 2.913". So your max length to fit inside the AR-10 mag is 2.840". To give yourself some room to play with in feeding and reliable functioning, you will want to seat the COAL about .010" to .020" shorter, about 2.820" or 2.830". That's the realistic max COAL measurements for your AR-10.
The Hornady Comparator tool you are using is for finding your base to ogive length, not the COAL. (See the picture below). The 162 A-max has a very long ogive to tip length. For this reason, it does not make a good AR-10 bullet, since it will have such a long jump when seated at the normal 2.800"-2.820" lengths. It is seated deeper into the case occupying more powder volume, and has a long jump to the rifling. It could still shoot well, and may work fine after you shoot it and see how it does. But the 162 A-max will have to be seated at normal length (about 2.820") and have a jump to the rifling when shot from an AR-10. I'm not sure what the ringlands are, but I'm assuming you're speaking of the rifling, or the lands. This is where the ogive of the bullet makes contact with the rifling, or rifling lands of the barrel. It is an important measurement when using bullets that are sensitive to bullet jump. The 162 A-max is an aggressive ogive design, and can be sensitive to the jump to the rifling. But if this is the bullet you want to run, you will have to seat it shorter and see how it shoots.
Most of the time gas guns run a lighter weight bullet, since the ogive to tip length is shorter, and it allows you to seat the bullet at normal 2.800" length, and still have a short jump to the rifling. Any bullet with a plastic tip increases the jump. So hollow points or soft points are popular. The 308 Win doesn't have this problem that much, but starting at the 7-08, down to the 260 Rem and 243 Win have this issue with their heavy for caliber bullets and longer ogive to tip lengths.
In an AR-10, it's important to select a bullet that will allow you ease of finding a good shooting load without it being picky on seating depth. Something like a Sierra 160 or 175 grain Gameking (lead soft point) or Sierra 168 Matchking would help in an AR-10. These bullets have a shorter tip to ogive length, and are more of a tangent ogive (meaning less sensitive to bullet jump). The Berger VLD bullets would not be a good pick in an AR-10, since they have a long ogive to tip length also. Some of their Classic Hunter bullets would be good, since they are a tangent ogive design.
You can see at the picture below the bullet on the right has a more "rounded" shape between the tip and the ogive. Where the bullet on the left is more straight and comes to more of a point, or corner, at the ogive. The bullet on the left is a secant ogive, where the bullet on the right is a more tangent ogive. Tangent ogive bullets are much less seating depth sensitive, and will tolerate a jump to the rifling better, which makes them better for an AR type rifle. But the tangent ogive bullets have a lower BC, so it's a trade off. Everything in shooting is a trade off. You have to decide what is your trade off and what you want to work with.
I'd say load up some test loads with the 162 A-max and see how it shoots. That will be the deciding factor.
Read these: http://www.bergerbullets.com/effects-of-...ve-cbto-part-1/http://www.bergerbullets.com/effects-of-...ve-cbto-part-2/