Chronograph

NZScotty

Member
Joined
Jul 12, 2020
Messages
8
Location
New Zealand
I bought a Magneto speed
I don't know what I'm looking for i know the smaller the S-D the better I shoot 3 10 shot groups. Just how small are you looking for ? Now that I have one how should I be using it?
Just out of interest, are you doing load development with the magneto speed attached?
If so, once you start shooting without it on your groups are most likely going to change drastically.
As already stated, your intended use of the rifle will determine how far down the rabbit hole of low SD/ES/group size you go. The lower the better, but on a hunting rig anything in the teens is good.
 

GLTaylor

Well-Known Member
LRH Team Member
Joined
Oct 11, 2019
Messages
1,008
Location
Cedar Bluff, Al
What does the paper tell you?
The target will tell you how well your load is grouping. A ladder test will show you where promising nodes are (similar impact points over a range of powder charges).
A good 100 yd group does not consistently make a good 300+ yd group. Lower SD and ES become more important as distance increases, as already stated.
 

Tom Erickson

Well-Known Member
Joined
Nov 16, 2019
Messages
120
Location
Minnesota
Lots of good responses, but wanted to reiterate as was said above that the best way to learn what you are looking for is to plug the fastest velocity and the slowest velocity into a ballistic calculator, individually, and determine what the difference in real drop is at your longest expected shot distance. Honestly, I then add a little 'me factor' to that delta, and decide if I need to improve the ESs. If any of this is confusing, or if you need help with inputting into a ballistic calculator, Feel free to PM me, and I will help/explain.
So let's say there is a 4 inch difference at 750 yards if I split the difference i would either be shooting 2 inches high or 2 inches low at 750 witch would be acceptable. Or am I looking at it the wrong way 🤔
 

Buster Hemlock

Well-Known Member
Joined
Feb 26, 2019
Messages
279
Location
NC
So let's say there is a 4 inch difference at 750 yards if I split the difference i would either be shooting 2 inches high or 2 inches low at 750 witch would be acceptable. Or am I looking at it the wrong way 🤔
Thats right, but thats just the error in your ammo, that doesn't include the gun and the shooter which will open it up more than that 4".
 

Bang4theBuck

Well-Known Member
Joined
Nov 19, 2013
Messages
445
Buster took the words right out of my finger tips. I call it error stacking. Example:
Rifle with awesome ammo, awesome shooter, awesome range, no wind= .25moa
All the same with deviation in ammo = 1 moa
All same with shooter in compromised position and heart pumping out of your chest= 2 moa
I usually try to remove all of the variables I can, and practice on the others before I go. The practice tells me just what my realistic range is that I should be shooting.
 

BoomFlop

Well-Known Member
Joined
Oct 16, 2012
Messages
645
Location
Wisconsin
So let's say there is a 4 inch difference at 750 yards if I split the difference i would either be shooting 2 inches high or 2 inches low at 750 witch would be acceptable. Or am I looking at it the wrong way 🤔

That is your difference in group based on velocity spread and it is not exactly an exact split as you described. Also, your example is assuming a rifle that is shooting a 0 MOA Load. Now add your actual group.

If you have a rifle shooting 1 MOA (that is a 7” group at 700 yards), now add the 4” difference of your velocity spread and you could miss 11” low. That is not acceptable.

Make sense?

Good luck,
Steve
 

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