Range Report 162 SST Ballistic Coeficient

[jsthntn247]

Hornady list the b.c. at .550. I printed off a g7 ballistics table which said that it should take me 10.1 moa to get to 600 yards with a chrono'd speed of 2900 fps. When I shot yesterday, it took me 11.3. I went back in the program and it said the bullet would have to have a b.c. of around .450 for this to be true. Anybody ever shot these and if so how true did you find the b.c. to published. This was out of a 7rem mag with 67.6gr of h-1000.

 

[MitchAlsup]

Re: 162 SST Ballistic Coeficient

Any chance that you scope is mounted higher than 1.5 inches above the bore?

 

[jsthntn247]

Re: 162 SST Ballistic Coeficient

Yes, it's 1.75 above bore. I added that to the program. A .450 b.c. gives me the same results as shooting 2776 fps, that sucks. I can only get to 850 before I am below 1000 foot pounds of ke. I can't get the darn Burgers to shoot or I would be using them.

 

[mclevela]

Re: 162 SST Ballistic Coeficient

Have you tried the Hornandy 162 gr Amax? Advertised BC of .625

I ran your numbers thru JBM and got 11.5 MOA come up for 600 yards with:
2900 fps, BC .550, scope height 1.75"
Since your profile is not filled out and you did not state ASL
I used 4,000 ASL, Temp 49 deg., Humidity 40%.
Energy is 915 ft.lbs at 1000 yards.

 

[BryanLitz]

Re: 162 SST Ballistic Coeficient

Have you verified the scope elevation adjustment is accurate? It's not out of the question that your reticle actually moved 10.1 when you dialed it 11.3 MOA.

You can check this on a 'tall target' at 100 yards. Shoot a group at your zero, then move the scope up 11.3 MOA and shoot another group. Then measure the distance between the groups and see if it actually comes out to 11.3 MOA. Also remember that 1 MOA is actually 1.047" at 100 yards, so 11.3 MOA should move the POI 11.83". Also remember to verify the 100 yards isn't 104, or 98, etc.

Good luck,
-Bryan