Hornady Ammo

decker · #1 10-02-2009, 10:12 AM

Last nite I was sighting in my 7mm with my new Leopold VX3. I got to hold a nice group at 100 Yards but when I moved back to 200 yards it was all over the place. Could this be the ammo or something else? Would not having your scope perfectly level cause this?

Dick284 · #2 10-02-2009, 10:51 AM

First off.
A single group at 100yds is not a reliable indicator of a loads performance.

Secondly, did you check your parralax on your scope to ensure it was indeed negated at 200yds.

Thirdly
A host of other issues could be causing this.

decker · #3 10-02-2009, 11:06 AM

[QUOTE=Dick284;401671]

Secondly, did you check your parralax on your scope to ensure it was indeed negated at 200yds.

QUOTE]
How do you do this?

Dick284 · #4 10-02-2009, 11:26 AM

With the rifle in a good firm rest line up on your target, and without touching the rifle move your head around a bit, if the cross hairs appear to move on the target you've got paralax.

If your scope is fitted with an adjustable objective or side focus you simply adjust this to negate the paralax. If you have no paralax adjustment, well, it's a case of either learning about it and living with it, or perhaps having it factory corrected for another distance, but that still will leave you with paralax before and after the set point.

decker · #5 10-02-2009, 11:32 AM

I will try that. Thanks

#6 10-02-2009, 11:37 AM

How all over is it at 200 yards? I can't see paralax making that much difference even if your scope is fixed at 100 yards. Paralax adjustment can fine tune at longer rangers but at 200 yards it's not going to make your gun shoot all over the paper.

Dick284 · #7 10-02-2009, 11:42 AM

Your right TJ, but take a look at the first consideration in my post, I'm pretty confidant that number 1 plus number 2 is accounting for his dilema.

1, 3 or 5 shot group does'nt always repeat it's self.
I've seen lots of supposed 1/2moa rifles suddenly become 1-1/2 to 2moa rigs.

Throw in a bit of paralax and voila you got a 4" or 5" maybe even 6" group at 200yds.

decker · #8 10-02-2009, 11:42 AM

It's shooting 6 to 8 inches. and not grouping.

#9 10-02-2009, 11:44 AM

Quote:

Originally Posted by decker

It's shooting 6 to 8 inches. and not grouping.

Definitely not paralax. Is your shooting ability a possible factor?

It's weird (not impossible) for a gun that groups at 100 not to offer a decent group at 200. Certainly better than 6-8 inches. A scope that isn't level can move your groups right or left at longer ranges but still wouldn't account for it being all over the place.

decker · #10 10-02-2009, 11:50 AM

I have shot multiple different rifles from a .243 to .338 Win Mag at this same distance and never had a problem grouping my shots. So I can assure that I have the capabilities to shoot this distance.

Dick284 · #11 10-02-2009, 11:51 AM

Decker:
Try a couple more 100yd groups, and see what the average size is.
Then try again at 200yds.
If the same thing happens as you discribed at the start, try letting another good shooter try it out.

If the 2 of you get good groups at 100, and junk at 200, I'd be looking at something mechanical, being wrong with your rifle. (optics, action bedding etc)

Short of actually being there to see what is happening, it's dang hard to even try and diagnose this.

#12 10-02-2009, 11:55 AM

Quote:

Originally Posted by decker

I have shot multiple different rifles from a .243 to .338 Win Mag at this same distance and never had a problem grouping my shots. So I can assure that I have the capabilities to shoot this distance.

Hmmm, then you do have a real mystery on your hands. Are you shooting off the same rest at 200 yards as you are for 100? Are you letting the barrel cool between groups?

Jerry D · #13 10-02-2009, 12:20 PM

Hmm it shot good at 100, and now like crap at 200 - Only thing I can possibly think of that will cause 6-8" groups is that your scope became loose.

I've never seen or known a gun that will shot 1" 100 yard groups and then 6" 200 yard groups and then when you go back to 100 shoot 1" groups again.

Quote:

Would not having your scope perfectly level cause this?

The answer to that is simply no. A scope that is unlevel will be unlevel for all your shots and therefor they should still all go to the same place.

Cowtown guy · #14 10-02-2009, 12:33 PM

Hey Dick or TJ...
How does a heavy bullet work in a slow twist? Will it be OK at 100 then start to wobble because of destabilization(sp?) at the longer range? Or will it shoot like garbage at 100 also? Only asking since Hornady offers an A-max which is typically heavier than conventional. I guess what load could be a question for the original poster.

#15 10-02-2009, 12:41 PM

Ya, you can definitely see long range accuracy go away with some bullets that shoot well at 100 yards but out of a 7mm it would seem weird at 200 yards. But ya, the bullet could be an issue but at 200 yards it seems unlikely.

BBJTKLE&FISHINGADVENTURES · #16 10-02-2009, 01:05 PM

I had the same problem with my .17hmr that Decker is talking about , all it took was tightening the Bedding screw as it was loose . Not sure if that is whats causing this . I use Hornady 139 gr ammo for my .280 and getting 2 inch groups bag on at 200 yards , then at 300 seems to drop about 2 1/2 maybe 3 inches . haven't tried past 300 yards.

Dick284 · #17 10-02-2009, 01:53 PM

Quote:

Originally Posted by Cowtown guy

Hey Dick or TJ...
How does a heavy bullet work in a slow twist? Will it be OK at 100 then start to wobble because of destabilization(sp?) at the longer range? Or will it shoot like garbage at 100 also? Only asking since Hornady offers an A-max which is typically heavier than conventional. I guess what load could be a question for the original poster.

Long heavy bullets can be under stabilized in some twists.
like TJ said, I too doubt you'd see good results at 100 and it go to pieces by 200.
More like 100 and 500 to see it happen. Or you'd see up front at 100, and beyond.

Jerry D · #18 10-02-2009, 01:54 PM

Quote:

Will it be OK at 100 then start to wobble because of destabilization(sp?) at the longer range?

A nice clean hole means a stable bullet - if you start to see oblong or oval shaped holes or holes that looks like the bullet went through sideways then your bullet has lost stability. With standard 7mm factory ammo using the recommended twist this would only become an issue at 800-1200+ yards depending on gun/velocity/bullet weight/twist... etc etc...

Quote:

Long heavy bullets can be under stabilized in some twists.

oh yea, - Barnes TSX normally recommend an inch faster twist rate than say a cup and core bullet of the same weight.

decker · #19 10-02-2009, 03:09 PM

Thanks for the tips guys, I am sitting in the office just itching to get home and do some more shooting.

decker · #20 10-02-2009, 06:54 PM

Well I bought some Remington 150 GR and first shot a group at 100 yards and it was low 2 inches low from where I wanted but was right on for verticle.
I brought it up 8 clicks and shot three more and was 2 inches high at 100 yards. I moved back to 200 yards and shot a 2inch group of three it was about a inch to the right so I moved 1 click to the left and shot three more and was right where I wanted to be. I am good with this.