Calculating moa ? HELP

[fm1947]

if you shot a 5 shot group at 300 yards but measured from end to end , I understand in competition you measure center to center, so in that case I would deduct size of bullet .308, so a 1.4 inch group -.308 would be 1.092 then divide by MOA correct me if im wrong moa is 1.072 that would equal 1.086 so now we were 300 yards so divide last number by 3 that would be .3395 End result is .339 MOA AT 300 YARDS

CORRECT???????????????

 

[fullersson]

I think MOA is 1.047 and some other numbers, but if you keep it simple and just say 1" per 100 yards. 3" is MOA for 300 yards so if you shot a 1" group at 300 yards you would have a .333 MOA. That's pretty good shooting.

 

[fm1947]

Your right 1.047, I was looking at some record shooting and wanted to try to understand how they officially come up with there final moa now I know thanks, I felt it was pretty good but some of those records in moa were really great

 

[Steve Blair]

Or, just multiply the 100 yard group size by the inverse, 0.954601227. For 200, 300 ,etc: multiply the previous result by 2, 3, etc.

 

[fm1947]

thats alot of numbers to remember

 

[Steve Blair]

I put it in a spreadsheet and do not need to remember it.

=AB70/(Z70/100)*.954601227

Where:
AB70 = cell containing group size in inches
Z70 = cell containing range in yards

 

[fm1947]

thanks

 

[BoydAllen]

One more thing, while we are being so accurate.....308 bullets don't make .308 holes. Measure a single bullet hole in the same target material and subtract that. It's nice to read of someone that is trying to get it precisely correct. So many times we have seen groups posted with measurements written on them that were obviously way off. Good shooting

 

[Steve Blair]

Boyd is right in that the target material, backing, bullet velocity and other factors influence the bullet hole size. That is why I like using "On Target" to record my group sizes. I can center the hole in the bullet diameter circle and get a reasonably accurate position, regardless of hole size. Scanning to an image also allows zooming to see detail that would otherwise be indiscernible.

The attached image shows several effects that can occur. This is a 100 yard group fired with heavy bullets, 210 Bergers. They are not quite point-on at that distance. The two shots on the left show the effect of shooting into an existing hole; it tends to be one-sided. Generally, the holes illustrated are not well-defined even though the target was printed on heavy card stock and backed by cardboard.

 

[fm1947]

interesting, your right bullets holes are not 308 just measured a couple , matter of fact they were about.155.

Well i needed to get close as i can that is why i stated this thread because today i shot 600 yards for the first time i had my calculations pretty close was off about 6in high and 5in right i was 0 at 300 so end result was best 5 shot group center to center was 4 inches so .663 moa i had another 5 shot that started out great at 2.5 inches but 2 fliers blew that one normally from 100 to 300 i have no fliers going to be a real challenge to get this 600 right, but over was happy with the end result and will work on my shooting and tinker a bit with loads, but for a factory out of box gun pretty good Remington 700 5r Mil Spec SS.

thanks everyone for your input