Range Report Hornady 75gr TAP questions

[upnorthbacon]

I just went out this weekend, I have some 75gr TAP ammo from my last AR build which was 1/7 twist and it shot fantastic. I thought I'd try it through my new savage 1/9 twist 26" barrel. I wasn't sure if it would even stabilize through a 1/9 after reading a few articles. Anyway it shot pretty darn well, in fact I shot 1 7/8" 5 shot group at 300yds which is darn good with me behind the trigger

I had a slight wind, probably 5mph at most coming directly at me 12 o'clock. I don't have a chronograph so my plan was to find out my drop and enter it into JBM and play with the numbers to see what I came up with for fps. I got 16" drop at 300yds which I came up with about 2600fps when I plugged everything in. That seems low to me considering I'm hearing everyone is getting more than that through 20" AR's and my barrel is 26"? I'm zeroe'd at 100yds, 45 degrees , 500 above sea level , and I'm getting roughly 1.75" height above bore line for my scope although I'm having a hard time measuring it? What has everyone else been getting on chrono's for this stuff and why would my drop be so much, would the wind coming at me have that much effect? I'm just getting into long range shooting so I'm kinda a newbie!

 

[MitchAlsup]

Re: Hornady 75gr TAP questions

I suspect your barrel is too long for the TAP loading--that is the bullet is actually decelerating in the last 2-odd inches in the barrel because the powder is all burned and the pressure is reduced to the point where it no longer accelerates the bullet.

 

[TresMon]

Re: Hornady 75gr TAP questions

I agree with mitch; It's probably a "generalised" loading to work in both an AR and a short barrel bolt gun, plus most all factory loads are a little light to be lawyer proof.

But it's in the neighborhood; Black Hill's 77 grain load quotes 2750fps, and their a lot less lawyer proof from what I understand.
I.I.R.C. the taps I had were shockingly slow out of my AR (20")

(L.E. sniper do not engage beyond 100m, and the load is proported as "no worries about pass throughs" to the LEO sniper. Perhaps they want them a little slower...

And yes, a headwind increases drag on the bullet, peeling off velocity faster. Go back to the ballistic program and plug in the headwind variables and that will get to closer to actual.

Wal-mart. com has(had?) a killer deal on chronographs.

PS. I'm not sure what you want to do with the tap loads, but they suck on deer.