Originally Posted by DocFoster
Originally Posted by Terminal223
We're at the range shooting now and buddy Jeff changed the velocity to reflect his 22" varmint barrel. I changed it back to what we are getting with the best accuracy load out of my 20" Krieger and CFE. Edited the chart above, it's closer but the 223 with TMKs still beats the 6.5 with the Amax.
For the last 4 or 5 years all I see on forums and gun rags is Grendel Grendel grendel and now that we are testing them side by side the 6.5 doesn't have as much of an advantage as we were lead to believe. When we weigh out the mag issues, bolts, cost of reloading and performance we are both thinking it isn't worth swapping over to the 6.5.


Wareagle 700 is right, your data is not right. I see 2 things that skew it.
First, although you said you changed the 223 data from a muzzle velocity of 2850 from your buddy's rifle to 2750 your data still shows 2857. Evan 2750 may be pushing it if your running a short throat.
Second the 123 gr. SST and the 123 gr. A-MAX has a BC of .510 not .462 as you stated in your original post.
Plug the correct data in and you will find the 6.5 still has the advantage and that why the guys that are in the know are saying Grendel Grendel Grendel.
Just a suggestion, accually do some shooting before you post your opinion relying on computer modeling which may not be right.
Doc

The true tested BC of the Amax and SST is not 510. That is Hornadys published BC but it has been proven wrong. We are shooting the loads I said and getting the velocities I said shooting 3 different Grendels and 4 5.56s side by side. .020" freebore doesn't make any difference in pressure because the bullets aren't stuffed into the lands.
My Iphone with AB program died so we started using an I pad and JBMs program online. The stupid thing works off their sever and changes the numbers as it finishes loading. At 300 yds the 77TMK is flatter than the 123, we can see that. We are working up loads at 300 to make sure we have the fastest accurate loads before we travel 2 hrs to the closest 1000yd range. Jeff and Bill were back out there today but i haven't heard anything. None of us plan to shoot more than 600 with these rifles, all of us have other rifles better suited for 600.
On another note have any of you tried the Beger 80gr Fullbore bullets in an AR loaded to mag length(2.28)?

Last edited by constructor; 06/05/16.
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