I did gather a bunch of data! I forgot to report back.
I saw on the western powders website that they have new loading manual out. I ordered it immediately. Looking online is fun. There is just something about books that i like better...
I tested the 2520 until .4 grains before max listed 5.56 data was reached. To my surprise on a much warmer day the 2520 shot around 35 fps less than TAC shot and a bit colder of a day 38° vs 49° or so. TAC has better velocity on a 38° day .4 under max than 2520 had .4 under on a 49° day.
My average velocity at .4 under max was 2750fps at 200 feet / 49° with 2520 out of my 16 inch barrel.
No pressure at these temps. None! No ejector marks, no extractor marks, round primers etc on this Lake City Brass. This Colt has a big chamber. The cases hold a lot of powder compared to some brands. YMMV.
I did a replay of my TAC loads and was unable to duplicate any good groups. As a matter of fact i stopped and pulled the rest of the bullets that night. This is not that accurate of a barrel in general... I did however find over a wider range, that the 2520 shot better. No real great groups and no real extra terrible ones. The worst were a nice close gathering and a pitched shot or flier. All were trying for 1.5 inch out of a military style barrel. I will buy some more 70's and start a little lower again on a warmer day and see what happens at max 5.56 data. Not to mention compare velocity notes.
I noticed that 2230 has the highest listed velocity for 70gr barnes.
I will buy some of that next time i go to the store. For the 70's and others i have on hand.
I am really hoping to find something that shoots accurately at around 2700fps and is hopefully around a grain below max. I would also like to see there be around a .3 tenth grain window for this accuracy.
While i am at it... Winning the lotto would be nice. Barnes bullets are F'ing expensive. I learned my lesson about load development. Usually i work up .2 tenths at a time in 5 shot groups.
Find the winning range and then build a bunch of ammo .1 ± and find the most steady shooter
I did that with my high dollar bullets and lost a lot of money.
Next time i see a great group i will only load 5 or 10 to see if it is repeatable.
I won't be able to shoot again until mid April or so. I will post back the results. 2520 again with likely 2230 and 2460 powders.
As of right now i am liking 2520 much better for this combo. 1.5 MOA maximum is more than adequate accuracy for me.
Last edited by aklaunch; 03/23/18.
