Build spin drift into scope?

[waveslayer]

Don't, just shoot straight to see how much drift you get. Or buy a left hand twist barrel since we are the Northern Hemisphere to reduce the effects of spin drift

 

[Canhunter35]

Don't, just shoot straight to see how much drift you get. Or buy a left hand twist barrel since we are the Northern Hemisphere to reduce the effects of spin drift

then the jag will unscrew from ur cleaning rod.
Calculate the necessary cant left you need to hold ur rifle to offset the effects of spin lol

 

[waveslayer]

then the jag will unscrew from ur cleaning rod.
Calculate the necessary cant left you need to hold ur rifle to offset the effects of spin lol

Ha ha ha ha ha that was funny.
There is a big movement doing gain twist and left hand twist at the same time. I only have a gain twist on my .338 Norma Magnum AI... it has been a tack driver. It will become more popular as the data and technology improves, but a left hand twist barrel is pretty money for us here in the US to reduce spin drift

 

[dfanonymous]

According to ballistician Jim Boatwright in his published papers, the spin drift is some invariable percentage of drop for any given combination. Most calibers fall between 1%-2% of drop.

You are right in that the spin drift is parabolic rather than linear. The drop is also parabolic, and therefore that percentage of spindrift each each rifle exhibits is parabolic.

It's pretty simple, go out and shoot at distance on a calm day. Experiment with using 1% and 2% of drop to see which one works best for you. There are some really complicated ways to calculate it that I don't understand. But even I can figure 1% and 2% of drop in my head and see which one is more accurate in conjunction with my wind calls.

If my drop is 20 mils, I'll experiment with .2mils and .4mils. If my drop is 50moa, I'll experiment with .5moa and 1moa. it really doesn't have to be any harder than that.

 

[Canhunter35]

How many guys here build spin drift into their scope via shooting slightly left during tall target test?

Purchase one of David tubbs curved reticles as another option

 

[sdecker]

ill sight in maybe .5 moa left at 100 yds I notice very small drift maybe 2" or so under 700 yds most calibers will see 5" or so of drift at 1000yds.being 1/2" or 1" left at 100 yds doesn't make any difference hunting but I don't worry about spin drift unless out beyond 1000 yd. At least that's how my rifle is shooting. take it for what its worth.

 

[Greyfox]

Years ago I used a canted crosshair(about 2 degrees for a 200 yard zero) to correct for wind drift. It worked very well but the canted crosshair in the sight picture was distracting. I eventually discontinued this practice, usually using the a ballistic calculator output for targets. For hunting where I determine wind using simple formulas, I compensate mentally for the spin drift correction,...generally, 1 click: 600-1000 yards, 2 clicks: 900-1100 yards. I use a similar approach for Coriolis when ranges approach 1000 yards with strong E/W azimuths. Correction values in both cases are pre-determined using a ballistic calculator.