Groups opening up ?

rebs

New member
A friend of mine worked up a load at 50 yds in his AR, but when he shoots at 100 yds the groups open up to 2 to 3 inches. What causes this ?
 

jmr40

New member
What size groups at 50, what type of sights? Much more info needed. Actually 2-3" at 100 is acceptable for most AR's unless it is a target model shooting high quality ammo with good optics.
 

rebs

New member
It is a Colt competition match hear with a Nikon 3-9x40 scope. He is shooting his hand loads 25.3 h335 with Hornady 55 gr soft point and mid south shooters 55 gr varmint nightmare xtreme hollow points
 

JohnKSa

Administrator
Generally speaking, one would expect groups shot at a given distance to double in size if the distance is doubled. As usual, it's more complicated than that. In practice, due to environmental factors and other considerations, groups might open up even more than that. But that's a good rule of thumb to use as a starting point for comparison.

That means if he was getting groups of 1" to 1.5" at 50 yards then groups of 2" to 3" at 100 yards wouldn't be surprising at all.
 

rebs

New member
How are so many guys claiming 1 inch groups at 100 yds with an AR 223 ? What are they doing that he is not doing ?
 

Nathan

New member
Better barrel and better bullets most likely.

With a std ar and std bullets, i would say 2-3" is normal.

What twist rate? Is he using 1 headstamp in a group?
 

carguychris

New member
Key question: Assuming this is an outdoor range, were the groups shot on the same day under the same wind conditions?

Gusty winds could have come into play. Additionally, even if a crosswind had a relatively constant speed, the presence of nearby structures, trees, or uneven terrain upwind of the range can cause unpredictable wind effects.
 

AzShooter

New member
I keep seeing guys at the range saying their ARs can shoot sub 1 minute groups at 100. When they pull in their targets they are all closer to 3 inches.

It can be done but you need to spend time at the press and at the range. Use different bullets and powder to get what you are looking for.

Cases need to be trimmed to length, Bullets need to be set out farther for a minimum jump to the rifling, etc.
 

steve4102

New member
How are so many guys claiming 1 inch groups at 100 yds with an AR 223 ? What are they doing that he is not doing ?


Testing Several different powders and powder charges.

Crimping with the Lee factory Crimp die.

What is the twist of that rifle?

My Colt is a 1-9 and shoots those Midsouth bullets into sub MOA groups with 748. It shoots 2+ inch groups with 335, 2230, XBR, and 2015.

I also have the triggers either replaced or worked on all of my AR's.

Lousy triggers can lead to lousy groups.
 

rebs

New member
His ar is all original, no aftermarket parts. The twist is 1 in 9.
The groups were all shot on the same day under the same conditions, 76 degrees and the wind flags were hanging straight down. No wind to speak of. His brass is new unprimed LC head stamp 16. We know different powders give different results, but guys on AR15.com and a few other sites are claiming 1 inch at 100 yds with the same load he is using. The brass has been chamfered and deburred, sized and all with in specs for length. Checked the scope mounts and rings, everything is tight.
 

jmr40

New member
No matter how good the equipment it still comes down to the person pulling the trigger. Has your friend shown that he has the shooting skills to shoot 1" groups with other rifles? Has he let someone else shoot his rifle?

I've found that a skilled shooter, with good ammo, a good scope, and a decent mid level or better AR is capable of putting 3 rounds into an inch at 100 yards most of the time. Even the best shooters pull a shot occasionally, and you'll get the occasional round of ammo that just doesn't fly right. And most of the lightweight barrels start to open up groups of more than 3 rounds.

Of the 3 AR's I own one will do it. The other two guns are generally in the 1.5-2" range. But the triggers aren't as good on them and I'm using 1-4X scopes on them vs a 2-8X scope on the other.
 

rebs

New member
yes he has shot 1" groups with my Ar. I can't under stand why his AR would shoot under an inch at 50 yds and then open up at 100 yds. If it shoots 1 inch at 50 then I can see 2" at 100, but not as much as his opens up.

To develop an accurate load for 100 yds should the testing be at 100 yds or can you get your best group at 50 and then go to 100 ?
 
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