Hornady SST's Shooting Lower than cheap Federal's

[bryceh12321]

I was just trying out some new ammo. Could anyone explain to me why a 300 win mag sighted in at 200 yards with 180 grain Federal Ammo
(Cheap soft point wal-mart) would place 180 Grain Hornady SST's 2 inches lower at the same distance?

I would have thought the SST's would have been shooting higher if anything.

 

[mikejonestkd]

Every barrel has inherent characteristics/ harmonics that determine the point of impact for various loads. It is very common for a rifle to have a change in the point of impact with different loads, even of the same weight.

On paper the SST SHOULD be impacting higher because of the higher BC than the Federal, but it is more complicated than just comparing the BC of the different bullets.

 

[bryceh12321]

On paper the SST SHOULD be impacting higher because of the higher BC than the Federal, but it is more complicated than just comparing the BC of the different bullets.

That's exactly what I thought. The only thing I'm thinking it might be is an error in the advertised velocities. They both show 2960fps, but maybe Hornady is using a 26 inch test barrel.

 

[FrankenMauser]

Federal tends to load hotter, for one thing.

Ignore the published velocities. Get your own data, or don't even factor it in.

 

[Huntergirl]

Clean the bore really good after using the Federals, then try the Hornadys again?

 

[precision_shooter]

That is kinda odd. I did a test a couple months back with my Tikka T3 lite in .308 to see how different ammo grouped.

I used to only use the Winchester 168gr. silvertip ammo. It grouped pretty well so I never tried anything else, just called it good enough.

At the range one day and I brought a box of the 168gr. Winchester Silvertips, 150gr. Federal Fusion, 150gr Wolf Gold BTSP, and 150gr. Hornady SST's.

I was surprised at the results:

1) Hornady SST - .75 inch group

2) Wolf Gold - .90 inch group

3) Winchester - .95 inch group

4) Federal Fusion - 1.15 inch group.

Now, these were only 3-shot groups and some will argue that 3-shots is not conducive of the accuracy potential of a round/rifle, yada yada yada. For me 3-shots is fine for a hunting rifle.

The interesting thing I noticed was all of the 150gr. ammo shot lower (about 1/2 inch) than the 168gr Winchester ammo. Not sure why, don't really care since it's still within the kill zone of any animal I might have in my crosshairs.

Here is a pic I took with my Cell Phone from that Range Trip. I thought it turned out pretty good.

 

[trooper3385]

The only thing I could think of is maybe with the higher speed, the bullet is still rising.

 

[tINY]

You have to consider the dynamics of recoil. The rifle jumps, the stock bends, your shoulder moves... All of this is happening while the bullet leaves the barrel.

Try shooting the same loads off of the bench with a bipod and then prone with sandbags front and back.




-tINY

 

[bcarver]

3 rounds

3 rounds or 5 don't matter as long as you compare apples to apples.....yada.

 

[fyimo]

I've had similiar thing happen and it has to do with your rifle and barrel. They do shoot diffent bullets from the same barrel with different results and there are a number of factors that have to do with it, harmonics, Powder speed, barrel length, bullet jacket material and thickness, Etc.

I was at the range today with my 35 Whelen and I zeroed it two weeks ago with 225 Nosler Accubond going 2700 FPS (book speed) and zeroed it two inches high for a 200 yard zreo dead center above the target. Today I was shooting 200 grain Hornady going 2800 FPS (book Speed) and I expected them to group nearly the same. The Hornday 200 grain rounds did exactly the same height but were 2 inches to the right. I zeroed the scope and shot 3 rounds into less the an inch with two bullets in the same hole just expanded a little and one 1/4 inch to the right 2 inches high dead center above the bulleye.

 

[Horseman]

You're likely seeing a different POI unrelated to velocity. It's typically for POI to shift among different loads. You're likely seeing a change in POI that just happens to be opposite the change in velocity difference of the 2 loads. Instead of the POI shifting left or right yours went down.

 

[jsr76]

You have to zero each load the exact same at 100yds. in order to see which one is flatter or whatever. You can't zero one and then shoot the other without re-zeroing, I hope you knew this.

 

[GeauxTide]

One point to consider

SST's have a boat tail profile, which isn't fully stabilized at 100yds. As stated before, adjust your scope accordingly.