Group size question 100-600yds (close groups opening up)

[nphunter]

I’m just curious if others ever go back and shoot 100yrd groups with their long range gun after load development.

When I built the rifle back in 2015 I was told to do all of my load testing at long range so all of my load development was done at 600 yards. A friend has a 1000 yard range which is pretty controlled environment, insulated building with heat and built in benches. Load was developed mid summer over a few weeks time.

Anyway I ended up with maybe 3-4 loads that were all sub MOA at 600. In the end I chose to use VLD 168s, the rifle is a semi custom 280AI. The rifle has always shot well and has killed a pile of animals for my wife and kids.

Anyway to get to the point, we went out yesterday to sight in a new rifle for my sister/brother in law and shot. Targets were from 100-620yds. I had first round hits at 2-400 10” plates with a 15mph side wind and then put 3 in a row about MOA at 620. While their rifle was cooling I decided to form some brass and also shot a 100 yard group. My 100 group was probably close to 2 MOA, I didn’t measure but defiantly over MOA. It was just barely smaller than my fire form ammo groups.

Is this something that should worry me? This is probably the first time I’ve shot a 100 yard group since 2015 with the rifle. It has been a while since I clean the rifle and I’ll clean it and try again next weekend. Should I just sit down and shoot 620 and if I’m still sub MOA forget about 100? That larger 100 yard group is really in my head right now.

I didn’t sit there and waste a bunch of reloads shootings 100 yard groups but feel like the group I shot were all good shots. Has anyone else experienced this? Next weekend I’ll sit down and shoot some long range groups and then retest short range.

Reloads are being loaded with the same specs, same powder and brass as 10 years ago. The rifle only had a few hundred rounds down the barrel.

 

[Formidilosus]

How did you determine that the rifle was sub MOA at 600 yards?

 

[Wrench]

You've got what most of us have....a normal rifle. I encourage everyone to be a thing hitter and not just a group shooter. Guys wear barrels out looking for some magical group size and in reality it's more an anomaly than reality. Few of those will go on to put rounds on targets to beyond their comfort zone.

I have a bunch of guns that are moa-ish and can hammer steel with pretty impressive regularity to quite a ways off. I learned to quit chasing ragged holes, keep the sd's in check and worry more about my field fundamentals than my gear. You can easily make a quarter moa error and never realize you did so.....and shooting at the 600 line and beyond makes it very evident.

 

[nphunter]

How did you determine that the rifle was sub MOA at 600 yards?

Maybe the wrong term. I was shooting under 6” groups at 600 many 3” groups or less, two of us shooting the same gun during load development also.

When I say MOA I’m thinking in my head 1” at 100, 10” at 1000.

 

[WKR]

Maybe the wrong term. I was shooting under 6” groups at 600 many 3” groups or less, two of us shooting the same gun during load development also.

When I say MOA I’m thinking in my head 1” at 100, 10” at 1000.

how many rounds were shot into those 600 yard groups?

 

[nphunter]

how many rounds were shot into those 600 yard groups?

5 when working up a load. 3 yesterday

 

[WKR]

5 when working up a load. 3 yesterday

Have you ever tried a 10 or 20 round group at 100 and then 600 to have a better idea statistically of what the load is capable of? It might just be the small sample size thats getting you.
I struggled with that a while back when I shot smaller sample sizes, then I started shooting a minimum of 10 rounds for a group at 100, then another 10 at 500-600 to verify, and every load I developed that way has held true without any doubts or questions like what you have going on right now.

 

[Formidilosus]

Maybe the wrong term. I was shooting under 6” groups at 600 many 3” groups or less, two of us shooting the same gun during load development also.

When I say MOA I’m thinking in my head 1” at 100, 10” at 1000.

As @WKR stated, you in all probability do not have a “sub MOA” at 600 yard rifle or load. You have small sample size bias.

Bet money if you shoot a couple 10 round groups at 100 yards they will be 2’ish inches, and if you do the same with no wind at 600 yards the 10 round groups will be 12-15 inches.

 

[Tmac]

Odds are it’s small group sample size issues.

But, if you have adjustable parallax, is it possible your scope parallax is set for longer distances, possibly inducing aiming error up close?

 

[eric1115]

100 yards just isn't far enough for the bullet to go to sleep.

Seriously though, what Form, wrench, and wkr said above is very likely the case.

Some guys do, I think, shoot poorly at 100 if they have a high magnification scope and can see every little tremor in the reticle, they subconsciously try to time their shot break with the reticle crossing center and shoot far worse groups. Less magnification calms everything down and allows a better trigger press.

 

[Lawnboi]

High magnification and inherent shooter error when you can see every motion, parralax and mirage likely account for a lot of the issues most see at 100 that they don’t further out.

 

[wapitibob]

Sitting at the range as I type, scope on 22x as usual, shooting at 100 because I just screwed on a new can. Dot in the reticle sits on a bullet hole.
Higher mag might be an issue if you shoot freehand or 50x, it isn’t if you’re on a bipod and bags and reasonable magnification.

 

[greyghostnw]

If it dosnt shoot at 100 yards it wont at 1000.