Berger vs sierra bt

[remcraz]

i have a question. Today i was trying some loads for my remington 700 7mm mag. I was reloading 71.5 gr. Of retumbo and was loading both 168 gr. Berger vld and 160 gr sierra bt. When i shot 3 shot groups at 80 yds. The 168 berger was 51/2 in. Lower than the 160 gr. Sierra. Was the sierra arching more at that range or was the berger just shooting flater and also is the 160 gr. Sierra a good long range bullet. I dont want to use the berger if they are dropping that much more than sierra bt. I CRONO BOTH AND THE BERGERS WERE SHOTING 2926 AND THE SIERRA WAS SHOTING 2976 Thanks ted

[7mmRemMag]

I am far from being an expert. But I would think the reason the why the Berger shot a little lower is because of the weight of the bullet and the speed. Its seems correct to me that the heavier bullet will shoot a little lower when trying loads. At least that has been my experience.

I dont think you would go wrong with either. I just started my long range shooting and have so far tested the sierra MK out to 575yards has been my longest kill so far on a deer. Although I have never tested the VLD berger myself, my friend has and he dropped a good buck at 300yards with his berger and his 7mmRemMag. I have read really good things on both the VLD and the SMK.

[remcraz]

Thanks for the reply. I didnt know if the 8 grs. Would make it drop the 5 1/2 in. No furthur than that.
Thanks again

[moombaskier]

I'm no expert either, but i'm positive that at the velocities you stated that there is no arc to any of those bullets in 80yds. On the contrary, I have found that heavier bullets tend to shoot higher at close range out of the same gun. Were you using the same hold or rest for each bullet, while making sure the barrel itself was not resting on something? Something's fishy! 5 1/2" at 80yds. seems like a lot of change.

[remcraz]

I was using the same rest and the barrel sticks out past the rest so the barrel is not touching anything. I am not an expert, it just didnt sound right to me. I didnt even remove the gun from the rest when i shot the 2 bullets

[Topshot]

I have noticed a similar thing with a .458 Win Mag. In that case a 500 grain bullet shot higher than a 350 grain bullet which is the opposite to what I would have expected.

I put it down to barrel whip. I think it depends on where the end of the barrel is pointing on bullet exit as to where the bullets land. It may be a case of one bullet exiting at the top of the barrel flex and the other exiting at the bottom of the barrel flex.

Try a different powder and primer combination in the 160 grain load to the 168 grain load and see what happens.

[MontanaRifleman]

Originally Posted by Topshot

I...I put it down to barrel whip. I think it depends on where the end of the barrel is pointing on bullet exit as to where the bullets land. It may be a case of one bullet exiting at the top of the barrel flex and the other exiting at the bottom of the barrel flex.

That is exactley what I think it is. When working up loads in my rifle, I will often see a 2 - 3 inch difference in POI when using the same bullet and only a grin difference in load. The difference is usually vertical or almost verticle.

That small differnce in velocity would not account for the difference in "drop" and heavier bullets dont drop any quicker than light bullets. If you hold a 300 gr bullet side by side with a 100 gr bullet and drop them at the same time, both will hit the ground at the same time.

It's almost certinly barrel harmonics IMO