A shot in the dark!!!!!!!!!!

[DalesCarpentry]

 I plan on doing some practice shooting between 300 and 600 yards pretty soon with my Remington 700 SPS 243 Varmint. With the 26'' barrel. Here is my problem. I am working on a chart for my scope so I know how many clicks to go up at different distances. The factory ammo I am using is the Hornady 58 grain Molly coated VMax rounds. The BC on this bullet is pretty low at .250 According to Hornady they have a MV of 3750 feet per second. I am almost sure that they mean out of a 24'' barrel. Well as you know my 243 has a 26'' barrel and I am sure the MV would be higher. I have no access to a chronograph so I can not do that. I bet the bullet leaves my gun at least 100 FPS faster than what they are saying. The thing is I ran the numbers both ways to see what the difference in the point of impact would be at 600 yards and I think it was about 15'' which makes drawing up a click chart worthless unless I can get a better idea how fast my bullet is leaving the barrel. I don't know if a reloading manual would have the information that I need or not. Do you have any ideas? Have any of you run this factory ammo out of a 26'' barrel and chronograph-ed it? Thanks a lot Dale

[corbanzo]

24-26" isnt going to make a whole lot of difference.  If you are going to practice distance shooting, then you can make your own chart, knowing at what distances to make a certain amount of clicks.  The velocity doesnt really make a difference, unless you have a trajectory calculator.  But the only real want to know if its right is to shoot it and see where you need to set your scope... once again having nothing to do with velocity. 

The gain between 24 and 26 inches is going to be a lot less than 100fps, though I'm not sure exactly what it would be.

[Hairtrigger]

I usually start at 200 yards and back up 100 yards at a time.
I put targets on a piece of 1/2" plywood that is 3'X6' with butcher paper covering it. for long range (to me) I stand the board on end so I will hit paper with considerable drop

[Graybeard]

The ONLY way you'll ever know how fast it's running out of YOUR barrel is to shoot it over a chrono. No amount of guessing is gonna get you there. Some barrels are faster and some slower than others and wild ass guessing is just that a guess. Until you run it over the chrono you might as well just work with what the factory claims as it's as accurate as any other guess.

[Don Fischer]

Without a chronograph, you'll never find the velocity. The up side is that a bit a variance in velocity isn't going to make that big a difference in trajectory at even 600yds. If you want, post the velocity here and I'll run it thru my trajectory program and tell you what I get. From there it is a simple process of fireing at different ranges to check on what your really doing. Oh yea, tell me how you'll sight it in too, I need that.

[Hairtrigger]

If you shoot at distances from 100 to 600 yards and start at 50 yards moving 50 yards at a time you can chart the drop. This would be actual drop and you would not need to know velocities, you could probably get very close to figuring the actual velocity

[Graybeard]

If you shoot at distances from 100 to 600 yards and start at 50 yards moving 50 yards at a time you can chart the drop. This would be actual drop and you would not need to know velocities, you could probably get very close to figuring the actual velocity

Well yeah....but..... that's assuming group size is small enough at all ranges to properly determine group center and thus actual drop. Of course if group size isn't small enough I guess when it ceases to be small enough that's a pretty good indication it's time to stop and not shoot at least at game beyond that point. So yes the method described is not only good but the best as those theoritical numbers tend to be off by quite a bit from real world experience.

[moxgrove]

One thing you may also want to check is the repeatability of your scope. You would be amazed at how many won't "shoot a square." When the distances stretch out that makes a huge difference. You really do needa fairly accurate average of you velocity as well. Maybe you could borrow a chrony.

[wyohandi]

You have to shoot it, even the best charts and programs will only get you in the ballpark.
Every gun does its own thing some predictable some not. And it is alot harded to be consistant
at 600yds than at 100. My 150gr 30cal bullets are supposed to have a BC of .330-.338 actual BC is .294
that in itself is a difference of 6-8"at 800yds.
And just because you shoot 1/2" at 100yds don't assume you'll be shooting 3" at 600yds.
Remember the no set rule rule. My 1 1/4" gun shoots 5" groups at 800yds (I must be screwing up just right)