bucksnbeagles

bigbulls again thanks for the help. Buddy I'm plum ignorant when it comes to MOA's and other terms but thats allright by me. Around home we, or I should say, I measure my groups in inches. What does a minute of angle convert to in inches? While I'm on the subject about being ignorant to terms, what does a ballistic coeffiecent mean when looking at ballistic tables? As you can see I'm as green as a gourd when it comes to hi po's.

stubblejumper

MOA means minute of angle.One MOA is so close to one inch at 100 yards(actually 1.047") that most people just call it one inch at 100 yards.Since it is an angle it changes with distance and equals 2" at 200 yards ,3" at 300 yards etc.Ballistic co-efficient refers to how well a bullet cuts through the air.A higher ballistic co-efficient means it will maintain it's velocity better over long distances and therefore drop less than a bullet with a lower ballistic co-efficient.Generally pointed boattails have the highest ballistic co-efficients while flat based round noses have the lowest ballistic co-efficients.

bigbulls

MOA or minute of angle translates to 1 inch at 100 yards, 2 inches at 200 yards etc... It's not exactly 1 inch per 100 yards but it is so close that it doesn't matter.

Balistic coefficent basically refers to the bullets aerodynamic ability to reduce drag. This number will change depending on the design (boat tail, flat base, round nose, etc...) and the velocity the bullet is fired at. The higher the balistic coefficent number the better the bullets aerodynamic ability wich translates to its ability to retain more velocity and be less effected by wind.

Sectional density basically refers to the ammount of penetration any given bullet will deliver in a straight line. Take a 150 grain bullet out of a 270. It has a sectional density of .279. To get the same sectional density in a 30 caliber bullet you would need roughly a 190 grain bullet. So 150 grains focused on an area that's 277 thousandths of an inch will penetrate better than 150 grains focused on a area that's 308 thousandths of an inch. In theory a bullets of the same sectional density, same construction, and impact velosity will penetrate the same target medium the same distance even though they may be different calibers.


I hope you can understand this and I didn't confuse you too much. If you need better explanation visit these links.

http://www.chuckhawks.com/bc.htm

http://www.chuckhawks.com/sd.htm

bucksnbeagles

Thank ya boys, I'm a getting there!

stubblejumper

With todays new bullets sectional density is meaning less than it used to as well.Bullet construction means far more than sectional density.For example the 7mm- 140gr failsafe or barnes x will easily outpenetrate a 7mm- 175gr corelokt or power point(or most 175gr bullets for that matter) although the heavier bullet has a much higher sectional density.Sectional density is now only a concern if you are comparing bullets of conventional cup and core construction .Even the new bonded core bullets behave differently.

handloader1

I would go with the .300 RUM. You can use it to kill any animal in North America, and if you handload, it is even more versatile. Good luck.

bigcountry

As a RUM owner, I will tell you, that the gun is very versitile. But if i had a STW, I don't see a need for anything else. I like that caliber also. I have been looking hard at WSM. I just can't seem to get them to shoot bad. Any of these will serve you well.

m2fin

I just sighted a Rem 673 .300 sa ultra mag. The trajectory statement is correct. Zeroed at 100m the POI as approximately 3" high at 60m with POI at 275m of -5". No windage drift with a light breeze to 100m.

Nice weight rifle, just over 7lbs with scope. Really nice shooter.