PDA

View Full Version : Drop at 200yds. with hornady bullets?


jaymag
December 11, 2008, 09:10 PM
I SHOOT 300GR. HORNADY XTP'S.With 130gr.of triple seven loose powder.I think it"s around 7-8 inch drops,from what i've read???

fastforty
December 12, 2008, 12:12 AM
You really need to chronograph what your bullet/load is doing out of your barrel to get an accurate drop. Once you've done so, any of several online trajectory calculators will give you a close estimate before you verify it on paper (I'm thinking it's gonna be a LOT more then 7-8"). I've never shot paper past 100 yards because the trajectory really starts tapering even at that distance.

jaymag
December 12, 2008, 09:28 AM
My triple seven 130gr. of looser powder is just has potent as 150gr. of pellets.Based on the 150gr. charge most 300gr. bullets where right around 7-8 inch drop at 200yds.I would probley aim 3 inches high over there back to insure a hit in the boiler room.Depending on the wind as well.

jaymag
December 18, 2008, 09:28 PM
Muzzloading is winding down here in ma.I positioned a ground blind for farther crossing areas.I really here no time to hit the range again.I know there is 0 drop at 100yds. with my set up.My new knight is very well capible of making shots at 200yds.Just looking for people that have made shots this far.Based on my appx. set up, thank you.

fastforty
December 18, 2008, 10:25 PM
Ok, I failed to realize that you were zero’d at 100 yards & were talking about the drop between 100 & 200 yards (we all know that the bullet starts dropping the instant that it leaves the barrel). I dug out my notebook to check some of my figures. I fired 6 different bullet weights over my chronograph & sadly, didn’t get data on my 300gr bullets because they were just too dang tight to risk getting one of them stuck halfway down the bore.

I fired 270gr Buffalo Maxi-Balls with 80gr powder & got an average velocity of 1267fps.
Zero’d at 100 yards, the trajectory first rises 2.2” then drops to “zero” at 100 yards. This equates to 2.2” drop at 100 yards. At 150 yards, it drops an additional 8.3” (for a total of 10.5” of drop from the muzzle). At 200 yards, it drops to 23.1” below the zero at 100 yards for a total of 25.3” of drop from the muzzle.

That was a little lighter bullet & charge then you were asking about. With missing 300gr data, the next heavier that I have is 385gr. which I shot over a 110gr powder charge for an average velocity of 1478fps. This combination first rises 1.5”, then falls to zero at 100 yards. At 150 yards, it falls an additional 6.1”, for a total of 7.6” of total drop. At 200 yards, it falls 17.2” from zero, for a total of 18.7” of drop.

As you can see (and I was already aware of), the trajectory of bullets in this weight & velocity range really starts to suffer past 150 yards. There has been a lot of debate about whether the 150gr “magnum” BP rifles are capable of getting much out of the extra 50grs of powder, due to the bullet being long gone before all of that powder can burn. All I can say there is to test fire the same weight bullet using various powder charges over a chronograph & see how much added velocity YOUR rifle gains. Then, input that data here http://www.eskimo.com/~jbm/ballistics/traj/traj.html to get a drop table that you can use to estimate holdover.

fastforty
December 18, 2008, 11:10 PM
I used to have a program that actually draws a graph of a bullet's trajectory after you enter speed, weight & ballistic coefficient. I've done quite a bit of searching and can't find the dang thing. I don't think that it was a java based thing (where you just go to a webpage, input data & it draws the graph), I'm pretty sure it was a freeware download program.

At any rate, this is a graph that compares the trajectory of .17hmr to that of a standard .22lr & it's not far off from the bullets that we are discussing here.
http://www.varmintal.com/17hmrdp2.png

The gold line (for .22lr) might be a lot like a standard 80-100gr BP load & the other lines might represent the gain that 150gr magnum BP rifles have. The chart does show how the bullet crosses the zero line on it's way "up", then again on it's way "down" at the distance the load is zero'd for & gives a good visual of it falling off rapidly past 150 yards. This is a pretty accurate picture of our heavy bullets do at longer ranges. Even though the faster bullet shoots a LOT flatter out to 100 yards & doesn't drop nearly as much at 150 & 200, it suffers the same downward angle at greater distances.

simonkenton
December 19, 2008, 08:23 AM
You can make a 200 yard shot with that load.
First you need to make your shot 2 inches high at 100. This will reduce the drop at 200.
Then take it to the range at see what it does at 200.

Wild Bill Bucks
December 19, 2008, 03:34 PM
Fast forty,

I think this is the chart you are looking for. Type in " Norma Precision-Ammunition" Then click onto "Ballistic" then to "Ballistic US" and give it a second or two to load.
This calculator will let you enter your velocity and coefficient, along with grains of bullet weight, and will give you a trajectory line for any given caliber. This is a very useful calculator, especially if you reload your own ammo, and have a good chronograph.

fastforty
December 19, 2008, 05:42 PM
http://www.norma.cc/default.asp?Lang=2#

Thanx, that one works pretty good, you can drag the bars around to change velocity, sight zero & sight height and the graph changes when you let go of the mouse button (there's a noticeable difference between low, open sights & a high-mounted scope). The one I had showed a bigger, easier to read graph, but you couldn't bend & twist it in real time (it drew a new graph each time a parameter was changed).