Elk Neck, Chrono needed!!! Any Help???

[Slayer2c]

Hi all! I'm in need of some help. I'm just getting back in to shooting after a few years break. I started back with a pistol and found it to not be challenging enough. I can burn through a few hundred rounds in an afternoon and make very nice holes in my targets but not feel challenged.
So I thought I'd get into the longer range rifle game and have had very good luck with a .308 remmington I purchased. I've been shooting it with very good results and groups at Elk Neck for about 6 months now and feel pretty comfident with my abilities. I've decided to get into a match series at which I'll be shooting out to 600 yards. I'd like to have a range card put together before hand but find I really need to know what fps my rifle is pushing. To do that I need a Chrono and just can't justify it to myself to use once. So I figured I'd turn to the net and see if I could find anyone going out to Elk Neck in the next few weeks to a month who would be willing to let me send 10 rounds through their chrono's. I'd be willing to meet you there any weekend you choose at just about anytime. Just let me know and I'll be there.

Thank you to anyone in advance of any help.

J

 

[1970swifty]

Oh just tell your wife it's to see how fast you push the buttons on your Xbox controller.

 

[Slayer2c]

That sir is a closely guarded secret!!!

 

[DZ]

If you want, let us know your rifle and load and we could probably get you on the paper out to 600.

 

[davsco]

this should get you close with fed 175gm. of course, you'll want to actually verify by shooting at these distances (even if you update fps with a precise chrono).


distance moa adj elev adj
0 - (1.50)
50 - (0.10)
100 - -
150 1.00 (1.40)
200 2.00 (4.40)
250 3.50 (9.10)
300 5.00 (15.70)
350 6.50 (24.20)
400 8.25 (34.90)
450 10.25 (47.90)
500 12.00 (63.30)
550 14.25 (81.50)
600 16.25 (102.60)

 

[Slayer2c]

this should get you close with fed 175gm. of course, you'll want to actually verify by shooting at these distances (even if you update fps with a precise chrono).


distance moa adj elev adj
0 - (1.50)
50 - (0.10)
100 - -
150 1.00 (1.40)
200 2.00 (4.40)
250 3.50 (9.10)
300 5.00 (15.70)
350 6.50 (24.20)
400 8.25 (34.90)
450 10.25 (47.90)
500 12.00 (63.30)
550 14.25 (81.50)
600 16.25 (102.60)

Thanks a lot these numbers are actually very close to mine. Now I am shooting the 168 gr that I know tends to scrub speed a little faster than the 175's but at 600 yards my calculations are showing me a drop of -106.37 which for a guess is very close to your -102.60 and should at least get me on the paper. Thank you. I know I have to verify it all for my actual range card but this really helps me not waste ammo.

If you want, let us know your rifle and load and we could probably get you on the paper out to 600.

I'm shooting the FGMM 168's zeroed at 100y, or as close to exactly 100y as I can get at Elk Neck. I've got a Remmington 700 AAC-SD with a 20" barrel and a 1:10 twist. Thanks in advance for any help!!

J

p.s. sorry for taking so long to respond, I actually typed all of this over the weekend but some dummy must of forgot to hit submit

 

[DZ]

Start here, they have some limited ballistics for FGMM 168:
http://www.snipercentral.com/308.htm

Take that info, and continue onto to:
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
Input your variables as best you can.

Using this info, I got "on-the-paper" at 800 yards (using M118LR), having never shot at a distance greater than 100 yards.

The data you find online will get you close, but as you know, there is no substitute for gathering your own data.

If you decide to go much further than 600, consider switching to the 175 grain bullet. You have the twist to handle a heavier bullet, and it'll get you to 1000+ yards before tumbling.

 

[Slayer2c]

The 175's are why I bought the AAC model, I could care less about the threaded barrel I just wanted the 1:10 twist to sling the 175's

 

[axshon]

I looked at the JBM site and was frankly a little confused since I have not learned all the terminology well enough yet. I found the GSeven calculator at http://www.longrangehunting.com/ballistics.html to be more helpful especially since they have a short set of videos describing its usage.

I'm shooting FGMM 175s on the 5R and found a couple of good posts at SnipersHide with MV numbers that are my starting point. Once I get to the range I'll validate and adjust. When I get to the shoot it will be my first time out to 600 yards so that should be a good learning experience.

Ballistics is fun stuff, I just wish I had more time to immerse myself in the theory.

 

[Slayer2c]

Check out Brian Litz and the readi g on the jbm site. He really breaks it down crayon style to those of us without physics degrees.

 

[axshon]

Didn't see that. Apparently I need to heed the advice I give my kids and slow down a bit... Thanks much!

Incidentally Slayer2c, what were the 0352's shooting when you left the Corps? They were TOWs on HMMWVs and LAVs when I got out. I was an 0351 SMAW gunner; don't hear so good on my right side anymore wonder why.. Semper Fi!

 

[Slayer2c]

We were shooting the bgm-71 foxtrots. When I got out in 98 not that we really ever got to shoot them often. The entire time I was in my platoon only shot a handful of live TOWs out at Gulf-3 out by the asp on lejune. I was in 2/6 anti armor. Hummer mounted but half my SOI class went to LAV's. When did you get out?

 

[axshon]

94 - I was a ground pounder with Kilo 3/8. We did most of our non-blue/green workup training out at LZ Owl off 17 and the woods (swamps) in that area near the hazmat dumping area that doesn't officially exist.

 

[lmorrison17]

Slayer2c if you still need to chrono your loads I have one right in North East. You can pm me.
Larry

 

[Slayer2c]

Larry thanks. I may be heading out the weekend after next. I will deffantly let you know and take you up on the offer if it works for you.

J

 

[lmorrison17]

So far I don't have any plans. Let me know.