Does this sound right?

[alphaburnt]

I had a scope that I had sighted in for 200 gr Shockwaves with 78 gr of WEIGHED FF T7. A fellow at the bench next to me was shooting some T7 50 gr pellets. I bummed enough to shoot two 290 gr Barnes TMZ ( 100 gr total of pellets each) out of my Elite. They grouped within 1.5" but were approximately 9" low of my zero for the Shockwaves. Does this sound odd or would there be that much difference in the two?

 

[jaybe]

That's a pretty radical drop, but since they grouped well, my guess is that there might have been something about barrel harmonics (barrel whip) that caused the difference. I think that 78 gr of WEIGHED T7 might be the approximate equal to two 50 gr. pellets.

 

[alphaburnt]

Something weird, the 290 TMZ over the 2 pellet charge seated deeper than the 200 SW over the 78 gr (weighed) charge of T7. This was verified by the witness marks I had etched into my ramrod. I know the bullet/sabot combo is at least 1/4 shorter for the SW. So maybe it is harmonics? Anyone else had a similar experience?

 

[bowhuntrrl]

You're talking about a bullet that is 90 grains heavier with an almost identical powder charge. It makes perfect sense to me !!! Of course the 290 grain will drop more, it's going considerably slower.

 

[Mike Vaccaro]

Harmoics are a funny thing. Bullet weight, powder types and amounts will drastically change harmonics. If the barrel is at the bottom of it's vibration\oscilation when the bullet exits the shot will be low.

Kinda funny, Webster says: oscilate-to swing to and fro.

Granted this video is of a 50cal but it speaks volumes to me. All guns flex\vibrate\oscilate or distort at the shot.

http://www.youtube.com/watch?v=s5pVya7eask


Henry