Quick Drop / Wind Brackets .223 trainer

[nettereo16]

Im working on improving my shooting ability for hunting. Ive set 2 identical tikkas - 18” .223 & 6.5cm, SWFA, assembled correctly.

I’ve made a lot of progress with positional shooting and “the hunting rifle drill”

I’ve read and mostly understand quick drop and wind brackets. Time to test it out & practice. How do you match training ammo to your guns so these concepts apply? Is it just chrono each round through your short barrel and use G1 bc to apply corrections? Or is there a better method before buying a bunch of different boxes?

Looking at the ballistic chart, my cheap 223 ammo seems way off. Is that just the nature of a lightweight short bullet doesn’t match the profile of more efficient ones? Trying to keep this as simple as possible across my two rifles and training and hunting ammo!

 

[Walker6]

Try playing with the zero range on your .223. Mine’s too slow with 77tmk’s but if I zero at 150-ish it gets close to QD from 300-500.

 

[Stinky Coyote]

Federal has a ballistic calculator you can run online to run all scenarios pretty quick to adjust zero distance to see where each for line up for qd the furthest and then keep adjusting wind value to see what speed it is where it lines up. My 223 with 73’s at 2730 lines up to qd within .1 to 600 at my elevation with 150 zero and is a 6 kmh wind gun or just under 4 mph, my 308 with 168’s at 2592 lines up to 600 with a 170 zero and is an 8 kmh (5mph)....you get pretty handy and fast running calculator, helps see what you have and also for future planning what you want

 

[24valve]

I’ve read and mostly understand quick drop and wind brackets. Time to test it out & practice. How do you match training ammo to your guns so these concepts apply? Is it just chrono each round through your short barrel and use G1 bc to apply corrections? Or is there a better method before buying a bunch of different boxes?

Could you clarify if you're trying to match the ammo to quick drop, each other, your hunting ammo, or something else?

Regardless of your end goal, do not change your zero from 100 yards.

 

[ElPollo]

Im working on improving my shooting ability for hunting. Ive set 2 identical tikkas - 18” .223 & 6.5cm, SWFA, assembled correctly.

I’ve made a lot of progress with positional shooting and “the hunting rifle drill”

I’ve read and mostly understand quick drop and wind brackets. Time to test it out & practice. How do you match training ammo to your guns so these concepts apply? Is it just chrono each round through your short barrel and use G1 bc to apply corrections? Or is there a better method before buying a bunch of different boxes?

Looking at the ballistic chart, my cheap 223 ammo seems way off. Is that just the nature of a lightweight short bullet doesn’t match the profile of more efficient ones? Trying to keep this as simple as possible across my two rifles and training and hunting ammo!

Quick drop and the good (fast) gun/bad (slow) gun correction factor should theoretically be able to work with any rifle/caliber/ammo combo, but it will be specific to that combo. I’ve been playing with a suppressed 11.5” AR lately with 77 TMKs at just under 2500 fps. It definitely requires a slow gun correction factor. From about 200-400, it generally lines up with about -2+5. It’s also 3 mph wind gun, which is frankly pretty challenging to get good wind calls down that to that precision.

I think that’s one thing that confuses people about quick drop. It only works across a certain range of distances. In the case of this AR, I don’t really need to bother with it up close because it drops a 1/2 mil or less. Beyond 200, it lines generally up with that correction factor, +/- 0.1 mil, out to 400. Beyond that it stars to drop a lot faster, but I’m unlikely to use quick drop in that case or shoot it at game due to lower velocities.

If I’m using a different ammo, I go through the same process of chronographing the load, calculating the data in Shooter, verifying that data on the range, and then I figure out my fast gun/slow gun correction factor and wind number. A 55 grain with an 11.5 barrel would likely have a much lower slow gun correction factor than a 77. If I was using a gun with a longer barrel, I might even get into a slightly negative, fast gun correction. The lower BC of a 55 grain FMJ, may also mean that your correction factor may only hold up across a narrower range of distances. You just have to plot the data, do a little math, and check it in the field.