Ballstics help

[MuleyHunterNV]

I plan on doing sme 1000 yard shots with my.270 winchester. I need some help on the drop.
I shoot .270 Nosler Ballistic tips in 130 grain. can anyone help?

[Springville Shooter]

What velocity are you shooting? I'll tell you right now that the 130 BT might struggle a little at that range, you might get lucky, but don't be disappointed if you can't do better than 3-4 MOA. If you're serious, there are bullets that will do much better. Get me a velocity and I can get you a ballpark number.---------SS

[chet]

ballistic coefficient is .433 not too shabby.....
assuming a muzzle velocity of 3000fps and a 200 yard zero, your bullet will drop approximately 312 inches at 1000 yards.

If you're dead set on shooting 1000 yards with your 270, try a berger in the 150 gr range.

[Springville Shooter]

ballistic coefficient is .433 not too shabby.....
assuming a muzzle velocity of 3000fps and a 200 yard zero, your bullet will drop approximately 312 inches at 1000 yards.

If you're dead set on shooting 1000 yards with your 270, try a berger in the 150 gr range.

+1.....I have seen guys have trouble with "hunting" bullets at 1000 yds even when coefficients are good. A friend of mine has a 7MM Rem mag that shoots 150 Nosler BT's into tiny bughole groups. The coefficient of this bullet is near .500 and he was still unable to get any type of grouping at 1000yds. Chets advise is good when he suggests the Bergers for your best bet. That being said, my 338 would shoot 225grn Nosler AB's near MOA consistantly so give it a whirl.-----------SS

[chet]

SS, explain this situation to me:

my 300win mag, shoots BT's and AB's well bellow MOA out to 300 yards. At 500 yards plus it opens up to 3 moa or worse. Bergers shoot 2-3 moa out to 300 yards or so, but tighten up and shoot 1-2 moa after that. same gun, same scope, same shooter....... I've heard of this before, in fact berger told me not to test loads at 100yards, the bullets need to "settle down". I'm struggling with the physics of this....... thoughts?

[Springville Shooter]

It has to do with the bullet spinning on its axis which is what causes it to remain stable in flight. Heavier, longer bullets are harder to stabilize initially hence the reason they have to be spun faster in the barrel to start with. However, once they do stabilize, they remain true for longer in flight and thus are better able to overcome the effects of drag and de-stabilization. Simply put, your Bergers are still wobbling around their axis when they leave the barrel, then somewhere downrange settle into their axis and true up......hope this makes sense? I have noticed that this phenomenon is much more pronounced when barrel twist rates are a little slower than needed to perfectly stabilize the bullets. In my long range bench guns with faster twist barrels, I don't notice this nearly as much and can usually shoot similar MOA groups all the way out.-----SS

[ntspdy]

Get your velocity and plug the data in here. Have fun.

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

[MuleyHunterNV]

My velocity is around 3100 fps. I hope that helps

[chet]

3100 fps would translate to about a 289" drop at 1000 yards if using a 200 yard zero.
You'll need a chronograph. Guessing your variables will not work while shooting 1000 yards.
Even when you think you have it dialed in, a little barrometric pressure change will throw it all off at 1000 yards. It's a long long long long long long long ways away and very few shooters are succesful at it.

[ridgetop]

I've noticed that most of the charts are based on a 24" barrel. Does a 26" barrel shoot a little flatter and by how much?