Is it me or what?

B

badshooter

Sergeant
Full Member
Minuteman
Feb 5, 2008
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South Arkansas
#1
I was at the range(as I call it) today. I fired some 175 SMK's at 300 yds and got this group below
175smk-1.jpg


Shots #1 and #2 was me shooting, shots #3, #4, and #5 was my dad shooting. What causes the bullets to ping pong back and forth like this? What are the chances we both pull a shot to the same point? I don't think it is the scope since it dialed up and down as I estimated and shoots this at 100yds
IMG_0589.jpg


5 shots 100yds. This group had a called flyer low as my footing slipped as I pulled the trigger.
 
#3
Re: Is it me or what?

Cold bore shot. Your first shot in a series heats the barrel and changes your point of impact.

Do a series of 5 shot groups letting the barrel cool between shot strings then note the POI change.
 
#5
Re: Is it me or what?

Are those 1 inch squares? Did you make a note of wind conditions before each shot (not saying that's the entire reason, but could be contributing factor)? In any case, looks like some good shooting.
Also, any sight adjustments in that string? I've had quite a few errant shots due to "chasing the spotter"
 
#6
Re: Is it me or what?

1 inch squares. zero wind. no adjustments. They are all low because the scope is dialed for my 155SMK load. I knew they would be low, I just wanted to get a idea on the grouping of the 175's so I didn't move the scope at all.
 
#8
Re: Is it me or what?

At 300 wind can be hard to see. Are you using any flags? Remember, due to the spin of the bullet a left to right wind can push the bullet right and down a bit. A right to left will go left and up a bit. Also if you have any 1/4 values or no value winds they can be very tricky if there is any elevation changes.
 
#13
Re: Is it me or what?

Two different shooters, two different cheek welds. It isn't uncommon for two people to shoot the same rifle/scope combo to different poi. Matter of fact it is uncommon for them to shoot to same poi from my experience.
 
#14
Re: Is it me or what?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bronco</div><div class="ubbcode-body">Two different shooters, two different cheek welds. It isn't uncommon for two people to shoot the same rifle/scope combo to different poi. Matter of fact it is uncommon for them to shoot to same poi from my experience. </div></div>

This
 
#15
Re: Is it me or what?

There is no visible problem.

I think we all may have missed the part about these two groups being fired by two different shooters. Each group, in fact, represents literally outstanding shooting by two different individuals.

It is not only common, but to be expected, that a single rifle and load combination will shoot to different POIs in the hands of different individuals. That's because the rifle and shooter form unique systems, whose recoil characteristics during the bullet's bore transit are by definition bound to be different for each shooter.

If the difference between the zero for 100yd and 1000yd is but 30MOA (that's half a degree, folks), then the difference in recoil response during bore transit resulting in a POI difference of about 10% of that is actually amazingly small.

What would be truly odd would be if they both shot to the exact same POI.

Greg
 
#16
Re: Is it me or what?

+1 with what Greg and bronco said ^^ they nailed it! Also, how can you start making assumptions about if there is something wrong with a rifle from one 2-shot, and one 3-shot group made by two different shooters. This is exactly what I would expect to happen from evaluating this target. Go back and shoot more groups with ONE shooter and if you still see a problem come back and post the targets so we can have a look at them. However, both of the 2 separate groups are MOA or better so whats the issue?
 
#17
Re: Is it me or what?

I think you guys need to read the numbers on the target, he is saying that it split the group when he shot and when his dad shot, those aren't two differant groups their one group with two shooters, and what are the odds that it will throw flyers that close with two shooters unless it is a prob with the setup, maybe he inherited the same exact shooting flaws as his dad, i think i'd look to the setup for the prob..
jmo..
 
#18
Re: Is it me or what?

Thanks for finally noting the group numbers MT300RUM. I had a hard time believing both of us pulled to the same point. It is correct that my group and my dads group was split. I shot a 1.5 inch group at the same distane just minutes before using 155SMK's instead of 175's. I'm just trying to figure out if it is the load or the gun setup. This was the only group that had a hint of a problem, all other shots were a lot tighter.
 
#19
Re: Is it me or what?

I've seen two rifles "two group" like that. Same shooter, but both were similarly though not so consistently the same when I shot them.

Possible bedding issue.

If a shooter issue, it would STILL happen with a "control" rifle. The best and most reliable approach requires changing only one variable at a time. One way to check for shooter effect is a good log which notes what shot number it happens on (the Grendel that did it was NOT consistent--odd shots from the magazine were at one spot for one group, then traded places with the even shots for another group). The next test I would recommend is a 2:1 ball and dummy exercise, with the shooter getting out of position and then rebuilding it for every shot. The rebuild prevents digging in variables, and the ball-and-dummy can isolate minute trigger/flinch effects of the tiniest sort.

Or you could buy a machine rest for the rig, which uses the same contact points as your firing position.
 
#22
Re: Is it me or what?

Badshoter, Did you use the same brass? I have LC Match and F.G.M.M. and with the same powder charge,primer,bullet They will shoot different points of impact. Also I agree with Vikings post too. Cold Barrel or clean barrel shoot different also.
 
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