Can anyone explain this

[lancetkenyon]

I am going to venture way out on a limb and say this is going to be a short range deer rifle. With a 16" 6.5CM running 140 NBTs, sounds like a stand rifle or pack rifle to me.

@ 400, there is only 2" difference in drops

At 500 yds (depending on environmental conditions), the difference in drops between 2553 and 2622fps is only 3.5". Or, 1.75" +/- POA if you zero for your average of 2587fps. What I would consider maximum acceptable and would limit my shots to here.

600+/- yards looks like about max to retain 1800fps impact velocity. But your variation in drops opens up to almost 6".

In other words, if this is a short range rifle, and keeping shots under 500, don't worry about it.

 

[Minero]

I am going to venture way out on a limb and say this is going to be a short range deer rifle. With a 16" 6.5CM running 140 NBTs, sounds like a stand rifle or pack rifle to me.

@ 400, there is only 2" difference in drops

At 500 yds (depending on environmental conditions), the difference in drops between 2553 and 2622fps is only 3.5". Or, 1.75" +/- POA if you zero for your average of 2587fps. What I would consider maximum acceptable and would limit my shots to here.

600+/- yards looks like about max to retain 1800fps impact velocity. But your variation in drops opens up to almost 6".

In other words, if this is a short range rifle, and keeping shots under 500, don't worry about it.

I hadn't looked at how it would affect short barrels, and by what you are saying, not that much, Personally don't like how rifles look with so short barrels, but that's just personal.

 

[cajun]

Get some 120 gr ballistic tips. They sell factory ammo. Really to little data but with that barrel your range is limited to where it won't matter much.

 

[NW Hunter]

Random thought….did you pull your rifle in tighter to your shoulder pocket on shot #2 without the muzzle brake? I've seen velocity increases when you do this.