Trajectory question

[recurve60#]

I know there are some gurus on here capable of helping me.
Farthest I can shoot on my range is 220yds.
Winchester 70 Featherweight 308, 20" barrel, winchester super x 180gr power points.
I've got a 1 5/8 group, 1.5" high at 220yd.
What roughly should this turn out to be at 300?
I know there's calculaters that do this, but I'm not experienced with them.

 

[recurve60#]

Btw what an awesome day to shoot! 70 degrees, just had to take time to let the wind settle a bit.

 

[DaveTN]

2.216 group, 16.5 in bullet drop, how that applies to your 1.5" would depend on where it was zeroed

 

[recurve60#]

I dont know dead zero. I sighted it in. 2.75 high at 100, that put me 1.5 high at 220

 

[DaveTN]

308 WinchesterSuper XPower-Point180 Grains
BALLISTIC COEFFICIENT 0.382, MUZZLE VELOCITY 2,620

DISTANCE FLIGHT DROP WIND DRIFT VELOCITY ENERGY
0 yds 0.00 sec -1.5 in 0 in 2,620 fps 2,741 ft-lbs
100 yds 0.12 sec 0.0 in 0 in 2,393 fps 2,286 ft-lbs
200 yds 0.25 sec -4.6 in 0 in 2,177 fps 1,892 ft-lbs
300 yds 0.40 sec -16.5 in 0 in 1,972 fps 1,553 ft-lbs

The Winchester Ballistic Calculator

The Winchester Ballistic Calculator allows you to select your Winchester product and view the real trajectory from that product. Compare up to 4 Winchester products and see how they compare.

ballisticscalculator.winchester.com

 

[recurve60#]

I think I may have worded my question incorrectly. The way I sighted in, 2.75 high at 100, 1.5 high at 220, what should I expect at 300?

 

[Remi]

Should be 7-8" low at 300yds but you'd really need to shoot to confirm

.380 bc
velocity of 2550 - just a guess

 

[TN Song Dog]

Looking at the data from Dave, if you verified your 100yd group is averaging 2.75" high...
At 300yd, you will be about 7.5" low

The attached dope is for 700ft above sea level, 40 degrees, and 40% humidity. MV of 2620fps

Note - your 1.625" group, at 100yd, will open up to about 4.9" at 300yd. So the above dope, at 300yd, will be +/- 2.45" margin of error.

 

[recurve60#]

Looking at the data from Dave, if you verified your 100yd group is averaging 2.75" high...
At 300yd, you will be about 7.5" low

The attached dope is for 700ft above sea level, 40 degrees, and 40% humidity. MV of 2620fps

Note - your 1.625" group, at 100yd, will open up to about 4.9" at 300yd. So the above dope, at 300yd, will be +/- 2.45" margin of

Its clover leafing at 100, the 200 yd group is 1 5/8, but I see what you're saying.

 

[TN Song Dog]

Its clover leafing at 100, the 200 yd group is 1 5/8, but I see what you're saying.

Right on, that's just good news added.

 

[DaveB]

Could I ask why are you shooting 180 grains in a .308? Just being nosey, nothing wrong with doing so.

 

[recurve60#]

Could I ask why are you shooting 180 grains in a .308? Just being nosey, nothing wrong with doing so.

More lead the better is my motto. I have my reasons.

 

[Wiley]

Everybody has their favorite bullet, arrow, etc. The .308 was built around a 168gr projectile. I load 165gr Speer 2034 PSPBT and it's sub MOA to 300 which is as far as I have shot.

 

[recurve60#]

Its spot on to 240 or so I reckon with a late 70's redfield to boot.