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OK you have a good shooting load for your rifle and you want to know how much it drops at different ranges.
You have a ballistic calculator on your computer but how good is it?
Probably not very good.
At Aberdeen Proving Ground we had the Army Ballistic Research Lab and had computer systems with chronographs running in the 5 digit figures price range.
They told me ballistic calculators are only right 5% of the time. If fired on the range your program might be dead on at 300 and 700 yards and off everywhere else.
Yogi was right.
Make up a target 4 ft wide and 8 feet high and put thin plywood or paneling on it and cover it with news print. You can get end rolls of news print from your local paper.
Zero your rifle for POA/POI at 100 yards. Place a new target bull at the top of the board. Using a weight and string draw a vertical line through middle of the target you aim at to the bottom of the target. From 100 yards shoot 3 shots.
Move back to 200 yards shoot 3. Then 300, 400 etc
Keep this up till you get to where your shots are not on the board.
You never touch the adjustment knobs.
When you finish measure down the center from the bull you aimed at each time and record how many inches below you hit and take the average. At Aberdeen these measurements were in millimeters.
Also measure how far the shots drift to the side at each yard line.
When you get through take the average elevation for each three shots and compare them to a ballistic program and see if they match.
Oh yeah you gotta do this in a no wind condition for best drift data.
At Aberdeen we did this for three rifles shooting 3 ten shot groups each and put all data on a sheet and sent it to a lab and they put data in a computer and the computer plotted the shots told us the size of each 10 round groups and calculated center of each 10 round group and the center of all three 10 round groups and plotted them and then averaged all three rifles for 9 ten round groups. No sights knobs were ever touched.
Our target was 32 feet high and 32 feet wide. The range was only 2500 yards long.
This is why when you see trajectory data from Aberdeen Proving Ground printed out you know it was from actual firing and not from a computer but the actual data is compared to computer projections.
CIP John Unertl was making the Marine Corps Sniper scopes in 79. He told me he had received five ballistic programs from five different sources and none were correct and none matched either. He asked me to get him data on M118 Match and I did and the data I gave him was right on the money.
When you die if you run up on a bunch of rag heads from Fallujah ask them if what they think of Marine Corps Snipers as they took out a pile of them and the methods they used was remarkable.
You have a ballistic calculator on your computer but how good is it?
Probably not very good.
At Aberdeen Proving Ground we had the Army Ballistic Research Lab and had computer systems with chronographs running in the 5 digit figures price range.
They told me ballistic calculators are only right 5% of the time. If fired on the range your program might be dead on at 300 and 700 yards and off everywhere else.
Yogi was right.
Make up a target 4 ft wide and 8 feet high and put thin plywood or paneling on it and cover it with news print. You can get end rolls of news print from your local paper.
Zero your rifle for POA/POI at 100 yards. Place a new target bull at the top of the board. Using a weight and string draw a vertical line through middle of the target you aim at to the bottom of the target. From 100 yards shoot 3 shots.
Move back to 200 yards shoot 3. Then 300, 400 etc
Keep this up till you get to where your shots are not on the board.
You never touch the adjustment knobs.
When you finish measure down the center from the bull you aimed at each time and record how many inches below you hit and take the average. At Aberdeen these measurements were in millimeters.
Also measure how far the shots drift to the side at each yard line.
When you get through take the average elevation for each three shots and compare them to a ballistic program and see if they match.
Oh yeah you gotta do this in a no wind condition for best drift data.
At Aberdeen we did this for three rifles shooting 3 ten shot groups each and put all data on a sheet and sent it to a lab and they put data in a computer and the computer plotted the shots told us the size of each 10 round groups and calculated center of each 10 round group and the center of all three 10 round groups and plotted them and then averaged all three rifles for 9 ten round groups. No sights knobs were ever touched.
Our target was 32 feet high and 32 feet wide. The range was only 2500 yards long.
This is why when you see trajectory data from Aberdeen Proving Ground printed out you know it was from actual firing and not from a computer but the actual data is compared to computer projections.
CIP John Unertl was making the Marine Corps Sniper scopes in 79. He told me he had received five ballistic programs from five different sources and none were correct and none matched either. He asked me to get him data on M118 Match and I did and the data I gave him was right on the money.
When you die if you run up on a bunch of rag heads from Fallujah ask them if what they think of Marine Corps Snipers as they took out a pile of them and the methods they used was remarkable.