Win XP3, Ballistic Coefficient

[travishunter3006]

I have been trying to figure out just what BC really is. The best way I can describe it is "a bullets ability to cut through the air"

I have been contemplating what bullet to have my wife shoot on the deer hunt this weekend, 150gr xp3 or 180gr xp3 (30-06). I won't shoot anything but the xp3's because of how this bullet worked on my cow elk hunt last year.

interestingly enough the 180gr bullet at 500 yards actually goes faster than the 150gr. I'm guessing this is due to its BC?


I finally understand what all that stuff means (kind of). now I need to apologize to some MMer's from about 6 months ago for all the sass I gave them about what I "thought" I knew.

My old eddystone 1917 likes the 180's the best. Can anyone tell me why? twist? barrel composition?

My wife is a dead eye, so After she tags her big 4 point this weekend, I'll post up pics of her's, mine and all the deer I helped my friends harvest.

30-06 SPRINGFIELD 180 GR. SUPREME ELITE? XP3?
BASIC INFORMATION
o Cartridge: 30-06 Springfield
o Bullet Weight: 180
o Muzzle Velocity: 2750
o Ballistic Co-efficient: 0.527
o Rounds Per Box: 20
o Rounds Per Case: 200
BALLISTICS
RIFLE BALLISTICS
DISTANCE
(YDS) VELOCITY
(FPS) ENERGY
(FT.LBS.) TRAJ.
SHORT TRAJ.
LONG
Muzzle 2750 3022
50 -0.1
100 2579 2658 0 1.9
200 2414 2330 -3.7 0
300 2280 2034 -13.4 -7.8
400 2103 1768 -30.0 -22.5
500 1957 1530 -45.1

30-06 Springfield 150 gr. Supreme Elite? XP3?
Cartridge: 30-06 SpringfieldBullet Weight: 150Muzzle Velocity: 2925Ballistic Co-efficient: 0.437Rounds Per Box: 20Rounds Per Case: 200
BallisticsRifle Ballistics
Distance
(yds) Velocity
(fps) Energy
(ft.lbs.) Traj.
Short Traj.
Long
Muzzle 2925 2849
50 -0.2
100 2712 2448 0 1.6
200 2508 2095 -3.2 0
300 2313 1782 -12 -7.2
400 2127 1507 -27.3 -20.8
500 1950 1266 -42.2






It was a big bodied 2 point.

 

[WesternSky]

You can think of a BC as measure of how aerodynamic a bullet is. If you think of a corvette and a jeep driving down the road at the same speed and they both put it in neutral, the corvette will travel further before coming to a stop because it is much more aerodynamic than the jeep.
Same thing with bullets. Two bullet weighing the same, but with different BC will have different trajectories.
The same thing applies to how much the wind will drift a bullet laterally based on the BC.

You do need to consider barrel twist when choosing a bulet weight. Heavier bullets need faster twist to stabilze the increased mass. With that being said, you often can shoot lighter bullets with a faster twist with aceptable accuracy. On the other side you may not be able to shoot a heavier bullet in a rifle that doesnt have enough twist.

 

[Cahunter805]

LAST EDITED ON Oct-19-11 AT 12:06PM (MST)[p]
Id shoot whichever the rifle likes. I personally don't care for the xp3 but if your rifle likes the 180gr go for it. Your rifle is most likely a 1:10 twist and could handle almost all 30cal bullet weights. Good luck and post some pics.

 

[Zeke]

+1 to the guys above....and....
Bullet twist is important and it's a hot topic when and if you're building a custom rifle. Until then, you should shoot a few rounds and see which YOUR gun likes. It may or may not have anything to do with twist. It may have to do with the barrel harmonics or "whip" from load to load. It would surprise you at how much a barrel moves around when it's fired. You're looking for consistency = smaller groups.

Shoot them and use what's best.

Zeke

 

[REDDOG]

LAST EDITED ON Oct-19-11 AT 04:41PM (MST)[p].

 

[VelvetyJones]

Come on reddog,tell us how you really feel?
this ought to piss the dawg off,right from winchester:

The new XP3? bullet starts with a two-stage expansion design, then combines all the best-known bullet technology into one bullet. It delivers precision accuracy, awesome knockdown power, and deep penetration all in one package - and it's as effective on thin-skinned game, like deer and antelope, as it is on tough game, like elk, moose, bear, and African animals, at short and long ranges.

note:'awesome knockdown power' (I didn't say it,winchester did)


[font color = red size = red size = 10 face ="face"]TAKE NOTE:MY SIGNATURE WON'T PLEASE EVERYBODY SO DON'T EVEN READ BELOW IF YOU'RE EASILY OFFENDED BY EVERYDAY BS ON MM[/font]

 

[travishunter3006]

I was just impressed with how well it grouped out of my eddystone 1917 at 100 yards and when i took my cow elk there just wasnt any room for any other bullet.



It was a big bodied 2 point.