7.62 bdc scope for grendel?

[6.5fanboy]

Hey guys, Im looking to build a 18 inch grendel AR, and I like BDC scopes from my time in the corps. How accurate would a 7.62 bdc scope be on a grendel platform? Im looking to engage 8 inch steel plates at up to 500 yards, so as long as I can do that I'd be happy. Thanks

[Bigs28]

I got a bdc for my 270 as my first gun and it worked and with nikons app i knew exactly how far each bdc was if i was at the right magnification (2nd focal plane). I now prefer moa or mil reticles in ffp because they are always true no matter what caliber i put them on.

[6.5fanboy]

Yeah, I was looking at the burris m tac 1.5-6, but I dont think they offer it in mil dots. Plus Ive never used mil dots before.

[kmon]

It wont be spot on but will be fairly close. One sure way to find out is to mount it on the gun and shoot it at ranges

[6.5fanboy]

Yeah I saw a chart and it had the different ballistics of the two rounds, they looked pretty similiar out to 600 yards, but I was wondering if anyone knew more in depth info.

[rabiddawg]

Hey guys, Im looking to build a 18 inch grendel AR, and I like BDC scopes from my time in the corps. How accurate would a 7.62 bdc scope be on a grendel platform? Im looking to engage 8 inch steel plates at up to 500 yards, so as long as I can do that I'd be happy. Thanks

Yeah, I was looking at the burris m tac 1.5-6, but I dont think they offer it in mil dots. Plus Ive never used mil dots before.

You never used mil dots in the corps?

[Lightning8]

I use the Primary Arms 4-14 with the ACSS for 308 for my 20 inch 6.5G. Works great at 300 yards.

[6.5fanboy]

You never used mil dots in the corps?

No, just the bdc on ACOGs... and the tracers on the 240 and gau16 haha.

[6.5fanboy]

I use the Primary Arms 4-14 with the ACSS for 308 for my 20 inch 6.5G. Works great at 300 yards.

hows it work at 200 and 500?

[Klem]

Two different ballistic curves so it's not going to work.

I don't know the exact drops on the BDC you are used to but it will be something similar to a Sierra 155gn @ 2,750fps.

Your 18" Grendel will get you around 2,565 for a 123SST.

The respective drops compared side-by-side out to 500yds with a 100yd zero are;



Let's face it, you are going to be trying different ammo in the Grendel and each will have it's own ballistic curve. None of them are going to match the 7.62 and on top of that you won't be able to use a ballistics calculator to help you.

[Jakal]

Or you could develop your handloads, buy a nikon scope with the custom xrt turret for that load and just dial up to 500 yards. Works great for my wife, as long as she has her laser range finder.

http://www.nikonsportoptics.com/en/Nikon...s-Overview

http://www.opticsplanet.com/nikon-monarc...urret.html

http://spoton.nikonsportoptics.com/spoto...on.html#:1

[LR1955]

Hey guys, Im looking to build a 18 inch grendel AR, and I like BDC scopes from my time in the corps. How accurate would a 7.62 bdc scope be on a grendel platform? Im looking to engage 8 inch steel plates at up to 500 yards, so as long as I can do that I'd be happy. Thanks

FB:

I did the same thing about ten years ago. I used a Nightforce Velocity Reticle made for 'low' velocity .308 which in ballistic terms equated to a Grendel firing a 120 grain Match King at about 2550 fps. I was pretty surprised that at 600 yards, the thing actually came within a minute in elevation. With all that said, the reticle was cluttered and difficult to use, just like any other fixed reticle. As for shooting 8 inch steel to 500, as long as you can see your sight picture clearly enough and you know if you need to hold or favor on the target, then it ought to be fine. You should look at a 10X in my opinion. Maybe 8 at the low end.

All that said, I would rather go with a reticle using minutes of angle. Probably a big tick each 2 minutes with a smaller one each minute. Many optics like this also have the lower minute increment cut into sections for range estimation. Pretty handy and not cluttered. Same concept for mils if you like using mils.

LR55

[Lightning8]

hows it work at 200 and 500?

There was a range in SW GA that had steel silhouettes out to 1200+ yards. Approximately one year ago I spent 2 days there shooting with multiple rifles. I had no issues hitting the steel silhouettes ranging from 200 to 800 yards with my 20 inch 6.5G using the discontinued PPU 120 and the PA 4-14 with ACSS 308 reticle using the reticle BDC - never dialed. Now - I am saying hitting the total silhouette steel which is torso sized not saying I was hitting an exact spot at 800 yards. Frankly - at 800 yards, I could not see the bullet impact - only saw the steel react and heard a strike.

[6.5fanboy]

thanks guys, I appreciate the input. looks like Ill go with some mil dots.

[jpm98vmi]

I've just started to evaluate it... but figure it's worth sharing the Nikon "Spot On" app. Available online and for both phone systems.
https://play.google.com/store/apps/detai...oton&hl=en
Just another tool in the toolbox.
jpm

[wheelguner]

Burris offers the ability to print out an image of their reticles customized for a given load. They also offer range card printing as well. Here is the link to their site:

http://ballistics.burrisoptics.com/

I am attaching a sample showing the MTAC 1.5-6 with the Ballistic CG and calibrated to the Hornady Factory 123gr AMAX. You will need to redo it for your geographic area and temperature.

It is easy to do. I think you will like the Burris Scopes. I have the XTR II 1-8x24MM Circle Dot First Focal Plane reticle on one of my Grendels. I prefer a true !X scope for close in work.
[attachment=5984]

[topcaat1]

I have an ACOG with a BDC cross hair reticle for a 5.56 20 inch barrel. Works great on my 6.5 Grendel with a 16 inch barrell using 107 SMKs or 108 Lapuas.
Muzzle velocity is right around 2525 fps. Did have to sight it in 2.5 inches high at 100yds. Using the 100 yd. cross hair its pretty much dead on at 200yds. At 3, 4 and 500 yds it hits within a couple inches of the respective cross hairs, Thats within the margin of error for me using a 4X scope. Despite what my ballistic software says, for some reason it hits about 6 inches low at 600 yds. Think it must be a problem from when the scope was made. Hits on 8 inch steel plates are easy out to 400 and not so difficult at 500 yds. In the past I used 123 grain AMax at 2425 fps. Results were similar but it was hard on bolts and brass with my prefered powder.
Not sure I would go out and buy an ACOG now due to the price, but love it on this rifle. Bought mine prior to a depoyment in 2004 before the Corps issued them to everyone, and took it on my next deployment because I trusted it. Now it has sentimental value. I think possibly BDC for 5.56 or 7.62 carbine might match even better?

[LR1955]

I have an ACOG with a BDC cross hair reticle for a 5.56 20 inch barrel. Works great on my 6.5 Grendel with a 16 inch barrell using 107 SMKs or 108 Lapuas.
Muzzle velocity is right around 2525 fps. Did have to sight it in 2.5 inches high at 100yds. Using the 100 yd. cross hair its pretty much dead on at 200yds. At 3, 4 and 500 yds it hits within a couple inches of the respective cross hairs, Thats within the margin of error for me using a 4X scope. Despite what my ballistic software says, for some reason it hits about 6 inches low at 600 yds. Think it must be a problem from when the scope was made. Hits on 8 inch steel plates are easy out to 400 and not so difficult at 500 yds. In the past I used 123 grain AMax at 2425 fps. Results were similar but it was hard on bolts and brass with my prefered powder.
Not sure I would go out and buy an ACOG now due to the price, but love it on this rifle. Bought mine prior to a depoyment in 2004 before the Corps issued them to everyone, and took it on my next deployment because I trusted it. Now it has sentimental value. I think possibly BDC for 5.56 or 7.62 carbine might match even better?

TC:

Not really surprising. Select a couple of common rounds of ammo and run them on a ballistics program that gives you a visual and numerical trajectory and compare them. You will find that to 300 yards, everything is very close. You may have an inch or so separating the least efficient to the most efficient. At 500 yards you will see some differences but for most situations, guys will still get hits on steel targets with the same hold or more centered hits with nothing more than a favor on the target being shot. Ballistically, you will see major differences when you shoot at 600 yards and farther. That is when you will either have to use full holds or use parts of the reticle to hold off. Hits become highly problematic, especially if you are holding off for elevation and windage. Thats why any of the 'Christmas Tree' or ballistic types of reticles like the ACOG will do just fine with the Grendel and any other cartridge to about 500 yards.

LR55

[kmon]

The marks will be on at some point but where that point is you would have to determine. Different atmospheric conditions, altitude and humidity will also play into effect, Same as if you get the "Custom Turrets for you load from scope manufactures".

[hardtoseeovergut]

What about a Leupold with CDS?