Quick Drop vs Danger Space

[RockAndSage]

5k ft DA changes can easily happen in a day, but you're right, it's not a make or break. Just another couple tenths of error. If you were already dealing with some error, it could put bump you out of the vitals. So maybe correcting within a day is a little over dramatic. But I personally have hunted 10k+ DA variations from one week to the next, so you might still be adjusting week to week.

DA and the ballistics calculations of all of this in precision rifle are still pretty foreign to me, I genuinely didn't/don't know how much it would need to be accounted for at 600yds and in, what causes changes in DA, etc.

 

[Kjc103]

I do practice quick drop. Question I have is why a bdc turret (ie one marked in yardage, not in angular measurements) is any more problematic than quick drop itself.

To me basic quick drop without a “correction factor” is simple and easy and makes perfect sense to me. What Im missing a bit is why a bdc turret is problematic in comparison, because all of the factors that add variability to a bdc turret, also add exactly the same variation to quick drop. So if you are willing to accept that quick drop is “close enough out to xx range”, why is a bdc turret any different? Is it simply that it prevents or makes it more difficult to utilize a correction factor? Or?

In either case a cartridge with more “danger space” will be more forgiving of any method that involves “close enough”. Seems a cartridge on the high-end of fitting into quick drop would be quantifiably better than a cartridge on the low end of fitting. At a minimum, from that perspective danger space seems relevant and beneficial to quick drop, at least to a point.

It’s pretty tough to argue with your logic here.

 

[Kjc103]

Another thing folks aren't discussing here is that cartridges with more danger space than a "good" QD gun would give are going to be high recoiling and/or have very limited barrel life and/or very restrictive barrel heating.

Any really fast 7 or 6.5 with high BC bullets kicks way too much for 98% of shooters to shoot well over and over again. Muzzle brakes mitigate this only on the surface, and make other aspects of shooting and communicating much harder (vs suppressors, which typically mean lower recoil cartridges).

A 6UM burns a barrel in under 1k rds, which I don't care about from a cost perspective, but from a simple reliability/usability perspective. You might be on shot 600 shooting fine and see the gun absolutely shit itself and throw grape shot groups by round 650. Next barrel might be good to 750 but you aren't sure and don't want to have it go out during a hunt, so you pull it at 600 just to be safe. At those round counts I would be doing a barrel every year or maybe every other year, which is simply too much hassle for me to tolerate. Or, I leave it alone and don't shoot it much - which to me is also unacceptable. I want to practice consistently with all my guns, since they are all different and require different input to shoot correctly.

22CM or some other fast 22 might literally be the only cartridge too good for QD that maximizes danger space and doesn't have any other horrendous drawbacks. Though barrel life is right on the line.

Good point.

I’m actually shooting mostly 308 right now simply for simplicity (QD) and barrel life.

 

[nm.otter]

DA and the ballistics calculations of all of this in precision rifle are still pretty foreign to me, I genuinely didn't/don't know how much it would need to be accounted for at 600yds and in, what causes changes in DA, etc.

Try some potential pressure altitude, temp and humidity scenarios in your ballistics app and see what happens to your charts.

 

[Macintosh]

Try some potential pressure altitude, temp and humidity scenarios in your ballistics app and see what happens to your charts.

The 270win Ive been using as my example has a .2mil change in dope at 600 yards between 0’ DA and 6000’ DA. Now, if we’re saying .1 or .2mil off from actual dope is acceptable as part of QD, then .2 isnt a lot. BUT it’s on top of any other error including QD’s +\- inherent “close enough” error, ranging errors, environmental, precision of gun, wobble, etc. FWIW my 6.5cm in the exact same situation has a .3mil change.

At the same time I think virtually no one goes up or down 6000’ in one hunt, that takes some serious elevation or a roughly 100-degree temp swing. It begs the question of how much change in DA is truly relevant vs just needlessly overcomplicating things; but also being cognizant that the error is additive and if you had .1 or .2 mil fudge-factor before, it may no longer be “ok” if that grows to .3 or .4+ without taking it into account. Also obviously if we’re accepting .1 or .2 mil error that is +\- meaningless at 300 yards, but probably meaningful at some longer range.

For you folks who use and have a lot of field experience with quick drop, where are your parameters as far as what is max “quick drop” range for a 1st shot at an animal (ie not for a follow up on an already-wounded animal), and how much change in dope does it take to cause you to make corrections to your qd math for environmentals?

It strikes me that a gun with higher “danger space” might be a tough fit for QD in the first place, but might be more forgiving of the max range where qd can legitimately be used, and of changes to your QD math. Those things alone seem valuable, maybe?