New rifle problems

[idaho 6.5 x 47]

A friend bought a cooper long range model 52 26 nosler.
only have shot box and half of nosler accubond factory a129 gr because he hasn't received his dies yet.
it will shoot a couple about 1 inch at 100 yards sometimes
then suddenly it will shoot two to 3 inches and usually to the right and low but not always
we Changed the entire set up , different bases , rings and different scope no change

3 different rests off the bench. 2 different shooters. Proper torque on all the screws
it's free floated , stock not touching barrel.
we will be working on reloading some 140 Berger's when his dies get here.

what do you guys think about this? I have 2 coopers they shoot great.
could it not like the factory load that bad?

i shot my 6.5-284 3 shots touching, swapped to his 26 nosler and shot 2 shots about 3 1/2 inches apart perfectly level with each other. I think that eliminated the rest. I was totally comfortable with the shots that it wasn't me.
we will be checking the seating depth with a modified case
what else should we look for? I'll post some pictures tomorrow of the groups

 

[B-LOT Banga]

Does it have a brake or suppressor? But it is still strange it will do 1" then jump to 2"-3" groups.

 

[wasskeet]

Inconsistent factory ammo? Or brake issue per B-LOT? Seems you've covered most typical issues well, but I might try screwing the brake off and shoot a couple groups. Unlike a Cooper for sure. Good luck with it!

 

[idaho 6.5 x 47]

It has brake

 

[ZAK13]

If it has a brake, that could be an issue. Or how long between shots? One right after another, or is there time given to let the barrel cool. Could be fouling as well, especially because the 26 Nosler is overbore. A friend of mine has a 300WBY, that after 5-10 shots needs to be cleaned, (most of the time a Boresnake will do the job), because accuracy just drops off.

 

[idaho 6.5 x 47]

Thats good thinking on the cleaning
Im going to guess 15 shots since cleaning
And it was getting worse by the shot.
thank you
I never thought that few of shots could potentially cause that.

 

[Bravo 4]

You have tried exactly 1 load in this rifle, and it doesn't care for it. You are waisting your time, energy, and money. Try a different type of ammo, clean the barrel to bare metal first. Doesn't Cooper send a proof target with the rifle? What ammo was used?

 

[idaho 6.5 x 47]

We are waiting on dies. I listed the ammo above
Nosler factory 129 accubond

 

[Hondo64d]

A friend bought a cooper long range model 52 26 nosler.
only have shot box and half of nosler accubond factory a129 gr because he hasn't received his dies yet.
it will shoot a couple about 1 inch at 100 yards sometimes
then suddenly it will shoot two to 3 inches and usually to the right and low but not always
we Changed the entire set up , different bases , rings and different scope no change

3 different rests off the bench. 2 different shooters. Proper torque on all the screws
it's free floated , stock not touching barrel.
we will be working on reloading some 140 Berger's when his dies get here.

what do you guys think about this? I have 2 coopers they shoot great.
could it not like the factory load that bad?

i shot my 6.5-284 3 shots touching, swapped to his 26 nosler and shot 2 shots about 3 1/2 inches apart perfectly level with each other. I think that eliminated the rest. I was totally comfortable with the shots that it wasn't me.
we will be checking the seating depth with a modified case
what else should we look for? I'll post some pictures tomorrow of the groups

A flyer of that magnitude says it's something mechanical to me. You could shoot the same load that Cooper shot their factory target with to verify, but my bet is there is something not ammo related going on there. I'd call Cooper.

John

 

[Bob Wright]

Check action screws while you're at it, if you were talking just scope mounting torque in your 1st post.

 

[26Reload]

I'd be more concerned about the fps for initial problems....even nosler hot loads could be shooting 'faster or slower' then printed...
My 26nosler shoots the factory 129 at 3200..not the advertised 3400..scattered also....
But my handloaded 142lrab shoot good at 3200fps....
Do a component check...pull a few bullets and check powder weight..see how much is stuffed in there....might scare you...
Had some federal blues for a 7wsm that were screaming and shooting allover the target....pulled bullets..weighed powder and about choked...called federal about it..he said that they loaded rounds to 'cup' and couldn't tell me which powder was used because they used whatever they had available.....
Haven't shot federal ever again....
But took reloading a lot more seriously......

 

[Veteran]

Yes, you can get a better handle on any ammo problems if you get the Chrongraph out, and check your velocities, to see if that helps diagnose the flier group disease. If its all same or close velocity without much ES or SD, then its the rifle somewhere somehow.

 

[dogz]

Midway has dies, over night them and get to it.....

Scope a proven honest scope?

Not using a bipod on the bench correct?

And like others before have mentioned, you've only shot one load I'd not get my boxers too tight at this time. The flyer would have my attention though

 

[Dosh]

Agreed with others, one load out of a new rifle tested isn't of any concern. Repost after the dies arrive and several loads tested.
Good Luck