HELP. I am shooting right at MOA up through 400 yards. But when I jump to 500 yards my groups open up to abot 10-12" - that's over 2 MOA. Beyond 500 yards, it's the same thing. Is this common? I assumed (barring shooter's error) that if a gun shots MOA at one distance it will shoot MOA at all resonable distances. I am using the 7RM Berger 168 VLD's.
Long Range Groups Opening Up
- Thread starter Rem 700
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- Thread starter
- #3
- Nov 4, 2004
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When you get out to 500 yds, things can change quickly. The equipment, including the quality of the optics and how it is set up, ES and SD of your loads, shooting rest, shooters form, and field conditions all play a role. I have always been a big coffee drinker BUT I only had a 1/2 cup the morning of a match and it made a big difference in my scores.
Go through the motions and make sure everything is tight.
JD338
Go through the motions and make sure everything is tight.
JD338
Greg Nolan
Handloader
- Nov 25, 2004
- 2,143
- 18
All the above plus any slight breeze will have greater effect as the bullet slows. What velocity does your bullet retain at about the 500 yd. mark. Does it go sub sonic ( about 1170 fps) . If so the boat tail will come into effect and if the bullet wasn't true to the bore axis it will show, from what I've read and the rate of spin may be slowed enough to de-stabilize. I haven't run into that but I don't shoot bullets that heavy for caliber.
I'm sure you'll get to the bottom of the problem.
Greg
I'm sure you'll get to the bottom of the problem.
Greg
Guy Miner
Master Loader
- Apr 6, 2006
- 17,525
- 4,785
Long range shooting is almost as much an art as it is a science.
It's not unusual for a Palma shooter, with a rifle built that easily delivers 1/2 MOA performance at 100 - 300 yards, to have big trouble making a 10" group at 1,000 yards. Huge trouble.
It's not straight line geometry. A 1" group at 100 yards does NOT equal a 10" group at 1,000 yards. Too many variables out there at longer range. Temperature. Mirage. Wind - and I mean wind so slight you can't even detect it on your skin, or on the flags downrange. These are not things the shooter can control. The better you are at doping this stuff, the higher your scores will be and the tighter your groups will be at long range.
Elevation is pretty easy, given quality ammo, from a quality rifle, and a skilled marksman. Windage is generally the troubled area. At a mere 600 yards, I've had a wind, almost undetected by me, widen my "group" to 18" wide... Yet I held to a 3" vertical spread... This was prone, with a sling for stability, and ten rounds fired. A .308 Win Model 70 match rifle with a 30" tight-bore Krieger barrel and a 12x Leupold. Very carefully assembled match grade ammo with Lapua cases, Federal 210 match primers and Nosler 155 grain match bullets atop a stout charge of Varget - a great combination for long range shooting - but still, my horizontal spread was a whopping 18" - and there was NOTHING wrong with the rifle, scope or ammo. On a completely still day I've shot the same combo into 2.5" at 600 yards. Not for ten shots mind you!
Long range shooting. Do some more. If you're not hooked yet, you will be. It offers up equal parts fascination and frustration.
Regards, Guy
It's not unusual for a Palma shooter, with a rifle built that easily delivers 1/2 MOA performance at 100 - 300 yards, to have big trouble making a 10" group at 1,000 yards. Huge trouble.
It's not straight line geometry. A 1" group at 100 yards does NOT equal a 10" group at 1,000 yards. Too many variables out there at longer range. Temperature. Mirage. Wind - and I mean wind so slight you can't even detect it on your skin, or on the flags downrange. These are not things the shooter can control. The better you are at doping this stuff, the higher your scores will be and the tighter your groups will be at long range.
Elevation is pretty easy, given quality ammo, from a quality rifle, and a skilled marksman. Windage is generally the troubled area. At a mere 600 yards, I've had a wind, almost undetected by me, widen my "group" to 18" wide... Yet I held to a 3" vertical spread... This was prone, with a sling for stability, and ten rounds fired. A .308 Win Model 70 match rifle with a 30" tight-bore Krieger barrel and a 12x Leupold. Very carefully assembled match grade ammo with Lapua cases, Federal 210 match primers and Nosler 155 grain match bullets atop a stout charge of Varget - a great combination for long range shooting - but still, my horizontal spread was a whopping 18" - and there was NOTHING wrong with the rifle, scope or ammo. On a completely still day I've shot the same combo into 2.5" at 600 yards. Not for ten shots mind you!
Long range shooting. Do some more. If you're not hooked yet, you will be. It offers up equal parts fascination and frustration.
Regards, Guy
Ridge_Runner
Handloader
- Sep 29, 2006
- 1,340
- 617
put a level on it and work on adjusting all the parralex out of your scope. without a way to level your rifle its just a stab in the dark.
and practice.
RR
and practice.
RR
Hi
I run into this also sometimes with the group I shoot with.
Given we don't know what the ballistics would be at 500 yards for what you are shooting, we would have to assume the bullet is transitioning from supersonic to subsonic. This can cause some stabilization problems if conditions aren't just right.
The first thing I would do is try another bullet, or a few others, at or close to the same weight, with the same load and see if the problem occurs with all bullets tried.
Another thing to try is shooting a lighter bullet, which would start out a little faster, meaning the bullet would transition farther down range.
Just a couple things to try. like Guy and everyone said, this is a science, but not a perfect science.. It requires much trial and error.
Keep us posted!
Good luck
I run into this also sometimes with the group I shoot with.
Given we don't know what the ballistics would be at 500 yards for what you are shooting, we would have to assume the bullet is transitioning from supersonic to subsonic. This can cause some stabilization problems if conditions aren't just right.
The first thing I would do is try another bullet, or a few others, at or close to the same weight, with the same load and see if the problem occurs with all bullets tried.
Another thing to try is shooting a lighter bullet, which would start out a little faster, meaning the bullet would transition farther down range.
Just a couple things to try. like Guy and everyone said, this is a science, but not a perfect science.. It requires much trial and error.
Keep us posted!
Good luck
Desert Fox
Handloader
- Aug 14, 2006
- 1,965
- 3
I doubt if the bullet go subsonic at 500 yards or 1000 yards for that matter. We're talking about a 168 grain high BC bullet at 7RM velocity here. Just because your rifle is capable of grouping 1MOA at 1, 2 or 300 yards doesn't mean it can be duplicated at 500 yards and beyond. As others have stated, there a lot of variables at play when shooting at longer ranges. When group open up at long range, the likely culprit were either wind or mirage. My 338 Lapua Ackley is capable of quarter of minute angle at 100 meters. I had 3 shot group with this rifle at 510 yards that measured 1.240". At 1000 yards, one might think I can print 2.5" group easily with this rifle. Wrong!!!! in a vacuum maybe.
Here's 4-5 shot group score from my last 1K competition. It's good enough for third place but none of the group came close to 2.5".
Here's 4-5 shot group score from my last 1K competition. It's good enough for third place but none of the group came close to 2.5".
Desert Fox
Handloader
- Aug 14, 2006
- 1,965
- 3
Elkman":bslaam5t said:
Yep! the top score was 193 with 7X. I missed up. I was using two different batch of reloaded ammo. Group #3 can attest to my screw up. It took two shot to get me back to center. The scorer told me later on that the last 3 shot on that group was less than 3 inch. Group#4 is even better if not for my first shot. The scorer told me that he can cover the last 4 shot with the palm of his hand.
Rem- A few more things to take a look at are your loads. Sometimes a simple primer change can tighten things up at longer range and still be great at closer range. Also careful loading practices and well prepped brass is a must for longer range. Sometimes a load will shoot very good at 100 but go to heck after that. Also sometimes a 2 MOA load may shoot that at 100 yards and still shoot a 2MOA group at 500 Yards. Also as DF stated your load will be well over sub sonic so I would't worry about that.
