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View Full Version : WTF happened to my groupings?


diego-ted
05-07-2011, 5:28 AM
I had a rude awaking on my 2nd time out with the Tikka. As I reported the first time out the rifle was flawless shooting less than MOA groups with Federal American Eagle and PPU match ammo. I had bought a couple of boxes just to try out the rifle. The ammo worked so well I bought a dozen boxes of each to better familiarize myself with the rifle.

On my first trip out, I discovered three busted screws on my scope rings. I got a new set of rings in, mounted the scope and headed out to the range with my newly acquired ammo. When I got to the range, I discovered they were reconfiguring the 100 yard range. It turns out the previous range was about 110 yards so they moved the firing line up ten yards. As I was honing in on my Zero with the AE ammo I could not hit the bulls my shots would wonder 1-3 inches. Before I attributed the problem to my newly mounted scope I switched over to the PPU match ammo. Although my groups shrank, they were still 1.5 apart and wandering. By now I was moving my scopes adjustment 1 click per shot but could not zero. I was frustrated to say the least. I let the barrel cool down and loaded up 5 rounds of Federal Match. I let the first shot go and it was in the grid. I loaded round # 2 and fired this shot was 2 to the left and 1 down from the first. I aimed again and fired this shot was a duplicate of shot #2. I fired three more shots and they were within .75 of each other. From here on out my groups were at least MOA.

So now, I am a believer that ammo is EVERYTHING almost. I could not believe the same ammo I was shooting MOA with last week, now would not shoot patterns? Did I just get some good ammo my first round out, and got junk the 2nd time I bought. Secondly, My cold barrel shot was 2 apart from subsequent groupings, is this common? Lastly, for consistent grouping what is the most efficient way to shoot, IE time between rounds fired? For accuracy with a bolt gun, is the only way to get accurate feedback, is to shoot match ammo all the time?

Thx Ted

rsrocket1
05-07-2011, 5:51 AM
Not to insult you or anything, but are you trying to adjust the scope with each shot or do you aim for the bullseye, firing 3-5 shots, then adjusting for the center of the group?

Secondly, ammo and your gun can be temperature sensitive. Was the first outing at a significantly different temperature than the 2nd time. It could be that the AE was on the edge of being consistent on the first day and in a "bad spot" or out of the accuracy node on the 2nd while the PPU was in the middle of the node and is more temperature tolerant.

When trying something new, whether its loading for accuracy or buying for accuracy, the more samples you take at different conditions gives you a better confidence level. I would recommend you keep trying the AE under different conditions to see what conditions it likes.

If your AE is really only 3 MOA under those conditions, then you can either sell it, trade it or simply use it for plinking or off hand practice with torso-sized targets. I don't expect any better with my Saiga using Wolf or Brown Bear so when I can keep my shots on an 8-1/2"x11" paper at 100 yards while standing, I'm happy.

At least you found one type of ammo your Tikka likes under both conditions.

Flouncer
05-07-2011, 6:32 AM
Something has gotta be loose.

17+1
05-07-2011, 7:15 AM
So now, I am a believer that ammo is EVERYTHING almost. I could not believe the same ammo I was shooting MOA with last week, now would not shoot patterns? Did I just get some good ammo my first round out, and got junk the 2nd time I bought. Secondly, My cold barrel shot was 2” apart from subsequent groupings, is this common? Lastly, for consistent grouping what is the most efficient way to shoot, IE time between rounds fired? For accuracy with a bolt gun, is the only way to get accurate feedback, is to shoot match ammo all the time?

Thx Ted

It happens man, some days the gun and you shoot really well. Others, not so well. Don't let it get you down. You're on the right track though, ammunition is more important that most realize. Don't let the barrel get hot to the point where you can't grab it.

I found that when shooting my Mauser, I like to fire 5-10 rounds during sight in period, even though I know my come-ups. This allows the barrel to foul slightly and brings the groups down to size. Match ammo is expensive, I have to reload to feed it to mine. It's the way to go though, especially at longer ranges where light loads fall apart, the heavy weight bullets are much more consistent.

CK_32
05-07-2011, 7:45 AM
I agree with all 3 above....

We all have bad days...

If not... I think you should shoot 3 and see a group and the middle of the 3 is your shooting spot... And adjust from there..

If that's not working make sure your gun and ammo aren't sitting in the sun or if they are make sure they are always in the sun. That will change POI.

If none of that then I say something must be loose or your scope is moving. Check and make sure your rigs are right. Last time out my badger rings came loose.. Didn't realize it until the last shot of the day because I couldn't hit a box at 200 yards...... After 10 shots I lifted my rifle in shame and felt the scope slide over on the base... Was depraved to see something was lose rather than me or my rifle not being able to hit a 10"x 5" bos at 200 yards.

wooger
05-07-2011, 7:49 AM
Depraved?

trashman
05-07-2011, 7:51 AM
Depraved?

LOL autocorrect I bet...

diego-ted
05-07-2011, 8:56 AM
LOL autocorrect I bet...

LOL, now back on topic!!

I do not think anything was loose, I will re-check. I did notice going from one set of rings to the other, which are the same height, my POI was 10" diffrent and I had to adjust the scope accordingly.

Diego

Mute
05-07-2011, 9:37 AM
There are too many factors that could have been an issue. However, Federal AE isn't exactly match ammo. On a factory gun, if you're even close to 1 MOA with the stuff, it's really not that bad.

I suggest that you first make sure your scope is properly mounted and secure. Don't worry about the change in POI between the current rings and the previous set. It's a moot point. After doing this, shoot more groups with quality match ammo like Federal Gold Medal Match to get a baseline on what your rifle is capable of.

I generally don't shoot on a bench unless I'm testing loads, trying to sight in a scope or trying to determine the capabilities of a rifle. When I'm doing any of the above, I'll use a good benchrest or at the very least a sandbag to put the rifle in a solid position and remove myself from the equation.

Lastly, regarding the impact shift between a warm and cold barrel you noticed isn't unusual with a factory gun. Even a custom gun will have a small shift, but on the best rifles I've had, that shift isn't much more than 1/2 MOA. Most of the time it's less. Good luck and hope you work it all out.

diego-ted
05-07-2011, 4:29 PM
Thx guys, I checked the rifle and all is tight. I am going to head out in the morning to shoot some rounds. Hopefully I will get a handle on it.

Diego

mattt
05-07-2011, 4:42 PM
When trying different ammo dont move scope until you find load you will use.A group is a group no matter where it is in relation to center of target. When you decide what ammo you are staying with then zero that ammo in.Any other scope adj is a waste of time and ammo

goodlookin1
05-07-2011, 5:07 PM
1) Reload

2) Every time you switch to a different ammo, your POI will probably be off target from your last zero

3) AE/Federal is at best, 1 MOA. Gold Match may be better, but nothing like reloading

4) If you've verified your scope mount is sturdy, may wanna look into your scope. It could be the reticle is floating around a bit. What kind of scope is it? Maybe it got damaged when you shot it while the scope mount was loose?

5) Reload. Yes, It's THAT important for high accuracy.


Good luck

22popnsplat
05-07-2011, 5:08 PM
When you cleaned your rifle did you remove it from the stock ? I have seen the torque on the action screws have a large affect on both group size and location . A consistan hold on the stock will affect things greatly also , everything must be the same every time .

RugerNo1
05-07-2011, 5:29 PM
There is also one more point to make. From your story you are saying that your last groups of the day were the best?

If so, it could be that the shooter was "warming up". Next time out, stick with the same ammo the whole time and see if your groups shrink the more you shoot.

You may notice that they will get better (warming up) then start to fall off again (starting to flinch).

Sounds to me like the you just need more time behind the rifle. Don't we all? :D

bruce_ventura
05-07-2011, 5:50 PM
Lots of good suggestions. I would add that it's difficult to draw solid conclusions from three-shot groups. There is too much variation in extreme spread from one group to the next. Its just statistics. I always test dispersion with five-shot groups.

diego-ted
05-08-2011, 6:24 AM
There is also one more point to make. From your story you are saying that your last groups of the day were the best?

If so, it could be that the shooter was "warming up". Next time out, stick with the same ammo the whole time and see if your groups shrink the more you shoot.

You may notice that they will get better (warming up) then start to fall off again (starting to flinch).

Sounds to me like the you just need more time behind the rifle. Don't we all? :D

Lots of valid points, I think this post is the most valid. The rifle lived up to my highest expectations, as did my shooting on my first outing. So I expected the same on my second. I was probably frustrated from sighting in and never fully relaxed afterwards, which affected my shooting. I need more time behind the rifle so I can become familiar with its patterns.

Diego

glockwise2000
05-08-2011, 6:58 AM
First of all, how do you do your groupings? Is it one shot then adjust or 3-5 shots then adjust. I highly suggest do the latter.

Or maybe, it could be just a bad day. Try another day with different weather condition.

CK_32
05-08-2011, 9:29 AM
LOL autocorrect I bet...

Yea......... That's an I phone for ya... :kest: