To the OP, it sounds to me like you are on the right track. If you are under 1/2" at 100 yds then that load should shoot well at distance. I had the pleasure of attending Dan Newberry's BangSteel school a few weeks ago. Rifles used in the class of 12 varied from newly purchased off the shelf hunting rifles to custom made rifles. The staff first verified 100 yd zero and grouping with each rifle. All were shooting under 1". Some were shooting hand loads, some factory ammo. Every shooter there successfully engaged targets from 600 yds to 1,100 yds. We were shooting steel plates. These varied in size from less than 1 moa to about 2 moa. One target was a ground hog plate at 660 yds. This plate was about .5 moa wide. There were first round hits made on this target. Given what I saw at this school, if you have decent shooting skills (the groups stated in your post indicate you do) you should have no problem at 600 yds. As was said earlier, learning to read the wind is the most difficult part. If you have a covered area to shoot from, try to shoot in some rain. Rain is a very good wind indicator and you can see what the wind is doing all the way to the target.
On buying all the latest books on shooting, you time would be better spent honing your hand loading skills, your shooting skills and learning to read the wind rather than reading a lot of theory. Race car drivers don't read and study how to build engines or how to design car bodies, they just drive the car. The more they drive, the more they learn about how the car handles and responds to them. Shooting is the same. You do need to know how wind affects your shots, not only on horizontal but vertical as well. You don't need all the theory associated with internal and external ballistics. If you are interested in this aspect and enjoy the reading then by all means pursue it. Just don't expect studying the theory to shorten your learning curve in practical application. Pick a rifle, a particular bullet and load, then shoot it as much as possible under varying conditions to see how it responds. Keep good notes from each range trip. If you shoot the same combination every time then after a while your wind calls will become almost intuitive. If you see results that are confusing, make note of it but don't obsess on it. Sometimes we just have a bad shot that we can't account for.
I also disagree with some of the posts above. If you developed your load using the OCW method (that is you have load in the middle of a node) then your load should shoot well at distance. But, the only way to know for sure is to shoot it at distance. If you can find a range where you can work your way out in 100 yd increments that would be great. If not, try to get a good MV estimate and then run a drop chart. Use this for your starting scope adjustment then shoot to confirm. Due to inaccuracy in scope adjustments or in MV estimate you may have to adjust the drop data. Record this as well. You can check your scope adjustment accuracy with a tall target test.
Since the nearest 600+ yd range is a 3.5 hr drive, you might want to make it a weekend trip. That would give you two sessions with changing wind conditions and you won't feel the need to rush your sessions. Or better yet, drive up on Friday night then you have all day Saturday and the option of staying for a Sunday session.
I highly recommend a trip to BangSteel (bangsteel.com). Dan's presentation and methods will have you successfully shooting at extended ranges very quickly.
FWIW,
Dennis
On buying all the latest books on shooting, you time would be better spent honing your hand loading skills, your shooting skills and learning to read the wind rather than reading a lot of theory. Race car drivers don't read and study how to build engines or how to design car bodies, they just drive the car. The more they drive, the more they learn about how the car handles and responds to them. Shooting is the same. You do need to know how wind affects your shots, not only on horizontal but vertical as well. You don't need all the theory associated with internal and external ballistics. If you are interested in this aspect and enjoy the reading then by all means pursue it. Just don't expect studying the theory to shorten your learning curve in practical application. Pick a rifle, a particular bullet and load, then shoot it as much as possible under varying conditions to see how it responds. Keep good notes from each range trip. If you shoot the same combination every time then after a while your wind calls will become almost intuitive. If you see results that are confusing, make note of it but don't obsess on it. Sometimes we just have a bad shot that we can't account for.
I also disagree with some of the posts above. If you developed your load using the OCW method (that is you have load in the middle of a node) then your load should shoot well at distance. But, the only way to know for sure is to shoot it at distance. If you can find a range where you can work your way out in 100 yd increments that would be great. If not, try to get a good MV estimate and then run a drop chart. Use this for your starting scope adjustment then shoot to confirm. Due to inaccuracy in scope adjustments or in MV estimate you may have to adjust the drop data. Record this as well. You can check your scope adjustment accuracy with a tall target test.
Since the nearest 600+ yd range is a 3.5 hr drive, you might want to make it a weekend trip. That would give you two sessions with changing wind conditions and you won't feel the need to rush your sessions. Or better yet, drive up on Friday night then you have all day Saturday and the option of staying for a Sunday session.
I highly recommend a trip to BangSteel (bangsteel.com). Dan's presentation and methods will have you successfully shooting at extended ranges very quickly.
FWIW,
Dennis
