• Please consider adding your "Event" to the Calendar located on our Home page!

Weird groupings, 2+2

Deja

Member
Jul 16, 2016
702
17
Vasa
Hi so this is a problem I get quite a lot. With all guns i have, my Vulcan does it and yesterday my rim fire. Has to be 50 +meters yards camels. Shooter error or parallax? 

I get 2 different groups that looks the same next to each other, lower target on the picture. 
2167cedb6d5407ef28b12b71d4fe12c5.jpg
 
I guess the trouble shooting methods used where I work might help.

Since it happens with multiple guns, I'm assuming it's not the guns, must be other factors.

How many shots in each group? Do you change magazines between side by side groups?

Can you identify any action between the groups, even something that shouldn't throw off aim? Do you load the bipod more on the second group than the first? Something else that simple?

Looks like you don't rest the gun no anything but the bipod, so bags under the stock or barrel shouldn't be the difference. Do you use bipods for all rifles that do this?

It comes down to identifying the things that are the same, and identifying what might be different on the second group. Sorry to stretch so far here, but trouble shooting from a distance is really difficult.

and no, I've never seen this before. Looks interesting though.
 
5 shot groups, single load

Hard to say about the load on the bipod. Im using the same one on the vulcan and on the rimfire. 

Yea your right bi pod might be the common thing here, tomorrow ill go out and try my benchrest. see if i can get the same thing, if not then I guess we know.

Check weld is another thing im kinda looking into, stock isnt quite high enough but next week ill have a riser to try.
 
Cheek weld - good catch. Is your scope a fixed parallax or adjustable? If it's fixed, are you shooting at the same distance that it's fixed at? Most (from what I've read) are fixed at 50 or 100 yards, and slight difference in cheek weld could be the issue.

There's a whole thread on parallax around here somewhere, so no need to rehash the subject, but could produce results like you displayed.

Now comes the fun part, testing (that means shooting), after all, isn't that why we are all here?
 
adjustable its a kahles target scope 10-50 usually keep it at 40. Main things to look into is parallax / cheek weld and the bipod.

Hynzie i got it right the first time but got unsure and changed it. back to the right form now. English is only my 3rd language so i get unsure at times. 

Sadly the rug isnt mine or the range i was shooting at. its the local shooting clubs 150 meter range because the ipsc muppets stole my 50 meter br range. 
 
Sad about the IPSC and the 50 meter range.

I think you are correct, look at parallax and cheek weld as most likely culprit. By the way for a third language, you do quite well. (I have no second or third language unless you consider Australian and British English as different :))

If you usually keep the parallax at 40, and are shooting at 50 or further, that could easily be the problem. Good luck in figuring it out.
 
If it were not for the fact that it seems to be happening on two different guns, and I ASSUME two different scopes, I would have shared my story about a scope............OK I'll share anyway. I had a scope once, no names mentioned to protect the Innocent, but this scope had a "loose" internal part that would literally shift internally from one position to the next, very seldom anything in between. Hence I would get the "double" grouping like you show in your pic. I found it by simply turning the scope to one side shaking slightly, then shooting. Then turning the gun and scope to the other side and tapping it, very slowly returning to the upright position and then shooting....and wahla, I would get two different groups. I no longer have that scope.

What scopes are you using? I assume you have double checked all the scope ring screws? (that happened to me once too, loose screw)
 
Could be any number of things. Ammo, the silencer, inconsistency in trigger control, hold, breathing, bad (or dirty) barrel, scope related, pulling the trigger (on a heart beat, or you just pull it), platform (which in all honesty doesn't look like a stable one), maybe your rifles need to be bedded, your barrel is touching the stock, regulator problems, not the right pressure (on a PCP), shooting unregulated, and so on... These groupings aren't that bad to be honest, especially for such a budget rifle. But if the results are the same with your rimfire and PCP, you might want to consider shooter error or platform related issues.