One 3" group or two .5" groups?

[93trojan]

I have a Dakota in 338 win mag driving me batty. I don't reload so I've bought a crap load of different ammo...could take on the Chinese army if I have to! Funny thing is, it has shot good groups with all the ammo...210-225 grain. Here's the problem. A typical 5 shot group could have 3 shots in .75-1" and 2 other shots in a .5" or smaller group....in two different places 3" apart It is random which shots go into the "right" group and which I considered fliers before. Couldn't help but notice that too many "fliers" ended up touching each other. Most of the time, they are high and to the right. At least 4 times I've thought, "Finally, found the right load!". Just in time for the same scenario to take place over and over.

Gun is fired about 5 times in 10-12 minutes...then a 10 minute break. Start session with a clean barrel and shoot about 15-20 shots overall.

Dakotas don't come with a free floated barrel. Since it seems to "wants" to shoot well, I think this might be the problem. What do you guys think?

 

[WildRose]

3" tells me something is really wrong!

Pull your action out and look at the stock. See if there is any indication it has been shifting inside the stock.

Reinstall and torque the action screws evenly.

Give it a whirl.

If that's not it, then my bet is there's something loose with the scope mounts or something inside the scope has broken loose.

If it were me, I'd do a good pillar and scim bedding job and make sure it's completely free floated before I put it back together.

You can waste a tremendous amount of time screwing with things that don't matter and in the end find out that floating and bedding was the problem all along.

 

[Alan Griffith]

Trojan,

I feel ya man! I too JUST had the similar thing happen to me. Several shots would make a very nice sub moa or even sub 1/2 moa group and the 1-2 would open it way up. I had it checked by our own 7mmrhb and he discovered.

1. Bad bedding job.
2. loose base screws
3. Bad crown job.

He fixed them all and it now shoots all in sub moa with good loads/components and if I do my part.

Alan

 

[J E Custom]

Not all rifles will shoot 5 shots in the same hole/group because there are so many varibles
that can cause fliers.

If it is a hunting rifle the need is for the first couple of cold bore shots to be on target.

if it is for targets there is no limit for the number of good hits.

So try to find out how many shots the rifle will place where you want it to and you will
know its limits.

Rifles with tip pressure(Not floated) typically respond this way because as the barrel warms up
the tip pressure changes or forces the action or barrel to move changing the POI.

Sometimes floating the barrel will stop the fliers but may open up the group s a little.

The fact that you don't reload is another possibility, Especially if the fliers come at different
times in the firing sequence.

In truth, If the rifle will hit your aiming point every time on the first cold bore shot and follow
up with another in 1/2 '' of the first you have a winner.

All of us would like our rifles to shoot sub 1/2 MOA groups until we run out of ammo but it is
not possible 100% of the time.

Look at the intended use of the rifle and if it will do what you need then be happy. I you want
it to do better than is needed then be prepared to get into reloading and spend time tuning
the rifle with bedding,floating,trigger improvements, Etc.

There is one final factor that we all have to face. Some days/times we just dont do as well
as we can at other times.

Don't be two hard on your rifle. It may be doing its intended job very well. you just may want
more like many of us.

J E CUSTOM

 

[rscott5028]

You've got plenty of good advice to think about from the previous responses.

If you're not well versed in rifle accurizing, (even if you are) I'd establish a good baseline before making any changes.

You have a lot of variables (rifle, ammo, scope, shooter) and possibly unrealistic expectations.

Stop shooting 5 shot groups with that rifle.

You need to work around 2 or 3 shots and then 15 minutes of cooling. Whatever you get for those 2 or 3 shots, see if it's repeatable.

-- richard

 

[dragman]

so many reason for this that it could be. One that it might be is paralax in the scope and how your holding the gun. paralax usually doesn't make that much of a difference at 100 but I know holding your gun different does. I have a gun that shifts POI 4" depending on how you hold it.

 

[Scot E]

You have received some good advice and the problem may well lie within those comments but the most common issue that describes your problem is shooter caused. Not trying to ruffle any feathers and I know everyone wants to blame the gun first but make sure you don't overlook form, specifically trigger pull, how the stock rides the rear bag, and consistent stock placement into the shoulder pocket.

Scot E.