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+--- Thread: Ballistic Reticles (/showthread.php?tid=306)
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Ballistic Reticles - Appalachian - 04-09-2011
How are these set up for 6.5G? Are there any made specifically for it? range turrets perhaps?
Ballistic Reticles - Anschutz - 04-10-2011
The round isn't really mainstream enough to have reticles build for it. As for turrets, I'm sure you can get a custom turret made using your load.
Ballistic Reticles - Appalachian - 04-10-2011
know anyone that does that?
Ballistic Reticles - Drifter - 04-10-2011
Check out the Velocity reticles on the Nightforce website. There's an online calculator there that will show how closely your load might match up.
Ballistic Reticles - LR1955 - 04-10-2011
Drifter Wrote:Check out the Velocity reticles on the Nightforce website. There's an online calculator there that will show how closely your load might match up.
Drifter:
I have a Nightforce 2.5 - 10 with the velocity reticle for the Grendel. If a person gets the 'Low Velocity' design I can assure them that it will be fine to 600 yards which is where you hit the duplex. However they better be getting something near 2600 fps and are using a well designed bullet or they will be sorry.
This low velocity pattern regulates very well when I am shooting the various 120 and 123 grain match bullets and holds within plus or minus a minute at even 700 yards (had to use a hold over) which is the farthest I have pushed it. I was actually very surprised it does as well as it does but when you look at it in ballistics terms, plus or minus a minute at 700 from a fixed pattern reticle is extremely good.
My advice to anyone who can get around 2600 from a Grendel with 120 grain bullets is that they are just as well served if they get a BDC designed around the standard .308, 168 grain match loading. Of course a person can spend a huge amount of money for a BDC that has stamped on it '6.5 Grendel' but otherwise is the same as a 168 grain .308 match load.
Simple rule of thumb. To 300 and the optic manufacturer will use the same increment on his reticle or BDC. The differences are so small that it doesn't matter. To 500 and any of the patterns designed around 2600 fps using about a .400 BC bullet will be fine. Past 500 and all bets are off, particularly with a Grendel.
No BDC or fixed reticle pattern will ever be a perfect fit but if you have one that gives you precision to within + - 1 minute at 600 yards -- you have a good fit.
LR1955
Ballistic Reticles - Drifter - 04-10-2011
Zeiss also offers ballistic reticles on some models, and they have a calculator on their website that indicates what power is optimum. With a second-focal-plane reticle and some calculation and experimentation, you can often get pretty close.
I've been the route of ballistic-type reticles before. But it kinda locks you in to a particular load. Thus, I've come to prefer a mil-based reticle with mil-based turrents, as the system works well with any load. For example, if your particular load drops 4.3 mils at 600 yards, and you have 0.1 mil clicks, you can either adjust up 43 clicks, or adjust up 3 clicks and hold on the 4-mil line of the reticle. If you change loads, it's easy to adjust accordingly. A first-focal-plane reticle makes the mil-mil system work even better, as it's applicable regardless of what power the scope is set on.
Ballistic Reticles - sloan - 04-12-2011
We bought a burris black diamond with labels in the box..it was easy to match up, the wolf was dead nuts out to 700yds,using the 308 label,an little hold overbe safe....
Ballistic Reticles - VASCAR2 - 04-12-2011
I bought a Mark AR 3X9X40 mil dot with bullet drop compensated turret and in the literature Leupold said you can special order specific turrets and the price was reasonable. The scope instructions indicate the rifle scope may be accurate to within 1 MOA with other calibers. Instructions also indicated if you sight the rifle in at longer range than 100 yards you can reduce the amount of error in the turrets by half. One feature of the Mark AR scope is that it is a front focal plane scope. I'm just waiting on the weather to change where I can get out and test to see how this really works on my rifle.
Ballistic Reticles - ARMANIAC - 04-13-2011
check out http://www.kentonindustries.com they build trajectory compensating turrets for almost everything. Great customer service also.
Ballistic Reticles - JASmith - 04-13-2011
You can also use the "QuickPix" calculator at http://shootersnotes.com/calculator/quickpix/. The utility lets you enter your range, drop & drift data, then calculate and display the sight picture needed to get a hit in the vital zone with a variety of scopes. The current selection doesn't go fancier than mil-dot, but you can get an idea of things. The site technical guru might also respond to requests to implement other reticles.
Ballistic Reticles - Bicyclewrench - 04-21-2011
I can confirm he does requests. It's a pretty neat application.
Ballistic Reticles - Bob Duncan - 04-21-2011
The Exbal ballistics calculator has a reticle analysis function. It produced the data below for the Vortex drop-dead bdc reticle. The "holdover" values are per Vortex for each dot below the crosshair. I have not tested these numbers yet. I did use this method on a Leupold VX-3 with a varmint hunters reticle and at 400 yards the POI was within 1/2 MOA of the POA. FWIW
ZERO MIN MAX MOA
BAR (yd) (yd) (yd) Holdover
(x-hair) 200 177 217 0
1 257 242 270 1.5
2 358 350 367 4.5
3 450 443 455 7.5
4 545 540 550 11
Ballistic Reticles - usar_ds - 05-01-2011
I have been looking for a new scope that has bdc for my 16" grendel carbine, was trying to decide between a viper pst with the mil ticks for hold overs or shell out for a custom reticule and I came across the leatherwood CMR
Apparently the on the leatherwood CMR the vertical bdc increments were designed to be used with 308 or 556. The end result being in between both rounds and comparing their specs sheet to my dope and ballistic calculations, it looks like they are almost identical to 6.5 grendel 120gr boattail hollow points at 2560 at all incraments all the way out to 900m...
Ballistic Reticles - JASmith - 05-01-2011
usar_ds Wrote:...it looks like they are almost identical to 6.5 grendel 120gr boattail hollow points at 2560 at all incraments all the way out to 900m...Be sure to use the trajectory for your barrel. The 16" barrel will give you almost 2400 ft/sec instead of the 2560. You'll probably see the difference!
You can explore the effects of barrel length by using the velocity estimator at http://shootersnotes.com/calculator/velocity-estimator/.
Then go to http://www.jbmballistics.com to see the impact on your trajectory,
Ballistic Reticles - usar_ds - 05-01-2011
thanks for the heads up, actually the loads I use are muzzle vel 2650 fps. so when shot through my 16" carbine they are about 2560, I double checked on that barrel length calculator, got the same result though.
thanks though, deffenatey will book mark that site for future referance.
Ballistic Reticles - bwaites - 05-01-2011
If you are pushing a 120 BT at that velocity from a 16" you are seriously over max recommended pressure.Be very careful!
Ballistic Reticles - usar_ds - 05-01-2011
if my calculations are off please let me know. probobly will save me some cash and frustration on buying a scope with the wrong holdover intervals
i dont load, i bought a press and dies a wile back but havent started loading yet, I am waiting for a class on it next month. dont wanna start till i know exactly what i am doing
i did the calculations from wolf mpt 120gr 2615fps
as well as having a friend at a gun shop reload some of my brass as well using sierra btjhp 120gr 2650fps.
dont own a chrono but used one wile on the range a wile back, fps was around 2560 for the sierra loads and 2510 for the wolf. chrono wasnt mine though...
sierra puts BC at .403 in that range, wolf doesnt publish the bc for their rounds,
I was running a millet trs-1 4-16x on the carbine but with a min mag of 4x and all the added size and weight it seemed not right to me for a carbine, so i transfered it to my ar-10, i was however able to collect dope out to 500yrds at a couple of different times of the year and the drop seemed very close to my calculations when taking wind, temp, ect... in account.
data i got from ballistics calculator that closely matches my dope out to 500yrds
yrds / vel fps / drop moa
0 / 2560 / -3
100 / 2347 / 0
200 / 2145 / 1.6
300 / 1952 / 4.5
400 / 1771 / 8.2
500 / 1603 / 12.5
Ballistic Reticles - JASmith - 05-02-2011
bwaites Wrote:If you are pushing a 120 BT at that velocity from a 16" you are seriously over max recommended pressure.Be very careful!Bwaites' caution is on the mark. The 2560 would be about right for a 19" barrel. A 16" barrel would likely get you 2480+-50ft/sec.
Ballistic Reticles - usar_ds - 05-03-2011
well thanks to both of you for the heads up, I will see if I cant borrow a chrono the next time i hit the range, hopefully i just have some erronious data recorded and am not shooting rounds that are dangerously over pressure.
I also contacted wolf ammo about the bc of their mpt rounds to see if i cant get some more Precise calculations regarding the drop of that ammo, and I will contact my friend that reloaded the sierra ammo to double check the pressure and vel of those loads.
we will see what happens with the chrono but I am guessing its back to the drawing board in my search for a new mid range optic.
Ballistic Reticles - LR1955 - 05-03-2011
usar_ds Wrote:well thanks to both of you for the heads up, I will see if I cant borrow a chrono the next time i hit the range, hopefully i just have some erronious data recorded and am not shooting rounds that are dangerously over pressure.
I also contacted wolf ammo about the bc of their mpt rounds to see if i cant get some more Precise calculations regarding the drop of that ammo, and I will contact my friend that reloaded the sierra ammo to double check the pressure and vel of those loads.
we will see what happens with the chrono but I am guessing its back to the drawing board in my search for a new mid range optic.
USAR:
What do you want to be able to accomplish with your carbine and optic? Hunting hogs to 300? Man size targets to 500? IPSC / IDPA?
State what it is you want from the carbine and the choice of optics with reticules becomes clear.
One thing I would not do is focus my attention on reticule patterns or BC's just yet. To 500 yards you can use any of the various bullet drop reticules made for 5.56 or 7.62 NATO and I will guarantee you success. Patterns should not be your start point as they will take you down the wrong path. Ergonomics based on intended use is a much better start point that takes you down the right path.
So, a better bet is for you to define your primary use of the carbine and from there a bunch of options will fall out and from them, different means of indexing elevation and different reticules.
Look at your reason for having the carbine, then ergonomics of the optic, then reticule patterns.
LR1955