I have been into the data again and have a good combination for you. Going to give it real time trials this upcoming weekend.
Trijicon ACOG 6X .50 BMG stadia. Started with a .300 win mag. Needed a muzzle vel of 3050fps, had to slow it down was punching 3296 over the chrono. Going to nail it down in the morning with 6 different loads.
Now here is the skinny on it. At 3050 FPS muzzle the 175 smk bthp from 100 yard sight in mirrors the trajectory of a 50 bmg, at its worst point of 600 yards it is off by .4 MOA. The rest are between .1 and .2 MOA of a dead on match and at 1,100 yards they are dead on as well as at 100!
The 300 win mag is a real barn burner with a 175 SMK. You can achieve supersonic out to over 1,400 yards. That is respectable! Recoil is moderate out of a 700 with 5r rifling.
Now for the fun info, 30-06 black tip AP projo, leaves the barrel at about 2750fps. The 300 WM will send it at about 3250fps out of a 26" bbl. Wonder if level 4 will stop the AP black tip at the velocity of the 300 win mag?
Excellent R&D. Keep up the good work and thanks for passing on the knowledge.
-------------------- On equipment: You get what you inspect, not what you expect. On training: Our drills are bloodless battles so that our battles are bloody drills. On tactics: Cheating just means you're serious about winning. Posts: 4314 | From: Central Virginia; VIM | Registered: Jan 2008
After 6 days in a row of range time I believe we have a winner. A 6 power ACOG 50 bmg, will mate 2 ways with a 175 SMK.
1. Load a .308 175 sierra at a muzzle velocity of 3050 FPS and you will convert the BDC from meters to yards with a .4 MOA at its worst point of 600 yards and it will be dead on at 1,100 yards, the read on the ACOG will be in yards instead of meters.
2. My preference, develop a load to a muzzle velocity of 3275 FPS with a 175 SMK it will mirror the .bmg 50 trajectory to within .3 MOA
My test rounds chronograph at 3039, 3039, 3041 extreme spread 2fps standard deviation 2/3 FPS
The faster load ended up with an average of 3273 with a deviation of 17 FPS which is acceptable. Going to lock both loads in and give them a test run this weekend on pop-up targets to 1,000 meters.
The results are in. With a 6X ACOG I had good and bad things to say.
The bad first. The ACOG is not very friendly on dealing with hold off for wind. You basically have to judge by target widths to compensate for the wind beyond the 600 meter range.
With a previous 100 meter zero here at home. I did a bit of wind judgment shooting on Friday prior to the event. The first shot was a cold bore shot with a 12mph 10pm wind it was at 1,000 meters and took out the target. I did 3 more one shot one hit at 1,000 meters as well.
The most difficult target was the 900 meter target. With no reference points on the optics it is extremely hard to judge the hold off for the wind.
100-1,000 meter the ACOG elevation was spot on. Just need a lot more practice with the wind read and trying to lead into it.
Solution at the moment is to mount a 5.5-22x56mm night force with one MOA stadia elevation and 2 moa stadia for windage.