25.06 losing accuracy??

[Bull Nutria]

My new weatherby Venture 2 sporter 25.06 groups have grown from 1 in to 2in with same load. what should i try? i have scrubbed barrel with bore tech eliminator. i previously found 50.0 g imr 4350 to group best with 117g hornady RN and 120 g Nosler Partition bullets.

should i start over and work up?
has this ever happened to your rifles?
what say you?
Bull

 

[Blue68f100]

Yes.

Several different ways a group opens up. One is when you have reached end of life of the barrel, aka barrel shot out. Copper Fouling can also cause this to happen. Most gun solvents do not remove copper. A look with a bore scope can show this. Throat erosion is another cause if your loads are tuned to a short jump.

Now if if this is a new load, it could have not been in the node. A change of components/lot numbers can shift a node. If a new gun you may have worked up your load before the barrel was broken in. If this is the case it can normally be recovered by minor changes.

A action screw has loosed up. This changes the tuning of the barrel harmonics.

 

[Captcurt]

I would check the action screws first with a torque screwdriver. You can google the correct specs online. Then the scope mounts. Then use a good copper solvent but be careful. Some of them are pretty stout and can cause damage if left in the barrel too long.

 

[Kaldor]

Assuming the barrel isn't shot out...

Check the screws, make sure they are all torqued to spec as others have said.

And buy a bore scope. They are inexpensive enough and can help clue you in what might be wrong.

The BoreTech copper remover works great if you need it. Not the biggest fan their carbon remover though.

 

[JDeere]

I would check the action screws first with a torque screwdriver. You can google the correct specs online. Then the scope mounts. Then use a good copper solvent but be careful. Some of them are pretty stout and can cause damage if left in the barrel too long.

This and Sweets works wonders on copper fouling when used correctly. Follow up with JB Bore Shine followed by Kroil patches. And last but not least the scope itself or the operator could be at fault. I have been known to have a bad day at the bench...

 

[dh1633pm]

Don't forget to check scope mounts and rings. Did anything loosen up? Scope still working like it should?

 

[tominboise]

You say it's a new rifle, so how many shots, roughly, through the barrel? How many 1" groups did it shoot before shooting the 2" group? Did it consistently shoot 1" groups over a period of range sessions, and now it's consistently shooting 2" groups over a period of range sessions? Did you change lots on bullets, cases or powder on the reloads used?

 

[Laphroaig]

My new weatherby Venture 2 sporter 25.06 groups have grown from 1 in to 2in with same load. what should i try? i have scrubbed barrel with bore tech eliminator. i previously found 50.0 g imr 4350 to group best with 117g hornady RN and 120 g Nosler Partition bullets.

I worked up a load similar to yours in my M700 that I thought shot about an inch at 100, 51.0 IMR4350 under a Sierra 117 PH. Last time I shot it it was bigger than that too. Scratched my head and promptly forgot about it. I still have a doe tag and the entire month of January to shoot one. Maybe I'll pick her to get the job done.

 

[1948CJ2A]

If the rifle is new like you mentioned, Weatherby does sub-MOA accuracy guarantees, I believe, so you could always engage them as a last resort. Although they will probably make you prove the accuracy issues with factory ammo and not hand-loads (that's what I would do if I were Weatherby).

I agree with what others have said so far. Check the action screws, scope mounts, etc for anything obvious or lose. How long are you letting the barrel cool between shots and what is the barrel contour? Pencil-thin lightweight barrels require more cooling time between shots for best accuracy.

Trying a new load altogether or factory ammo is probably something I would do anyways just to get more data accumulated.

 

[longdayjake]

I used to think that my guns were wearing out. Then I realized I'm getting old and my eyes are wearing out. My heartbeat is different. My muscles are weak. I just suck.

 

[Bull Nutria]

Update:
approximately 300 rds firwd thru rifle.

I looked up torque for rifle.removed rifle action from wood stock.applied grease to bottom of barrel etc. retorqued bolts to 35 in lbs.alplied blue locktite.
reloaded new rds starting at48.5g every half grain to 50 g.. see photo

note most all hits about 1 in high. yesterday 120 partions were 4 in high.no real good groups.

photo 2 is 117 g hornady RN.THESE MADE BEST GROUP WITH 49.5g squares i adjusted scope 4 clicks left before shooting the 50 g load circles.
there was a 10 -12 mph left to right crosswind range. evidently action bolts caused rifle to shoot 3-4 inches high

yesterday.
i cleaned barrel with boretech eliminator prior to shooting today.
What say you

 

[rg1]

Wood stock? If so check the stock to see if it’s touching the barrel at any place. Take a dollar bill and slide it up or down between the barrel and wood. Warpage can move your impacts 2-4”. Had a Weatherby Mkv that warped and scraping the wood where it touched the right side put groups back in the 1/2” range. Don’t go scraping any wood before you know for sure what you’re doing. Can ruin your stock! Weatherby stocks can have pads that the barrel is supposed to touch! But if the barrel is touching on the right and not the left it could be warped?

 

[1948CJ2A]

Do you have any other bullets to try? Seems like the 120 partitions and 117 RNs were what you were using when you originally reported the accuracy issue.

I've used 100gr Nosler Ballistic Tips and 110gr Nosler Accubonds in my 25-06 with success in the past.

 

[AJC1]

Don't forget to check scope mounts and rings. Did anything loosen up? Scope still working like it should?

Running a quick scope box test tells a lot...

 

[Bull Nutria]

I did the dollar bill test . good clearance between stock and barrel. i didnt mention that i sbot some 100 g Hornady SP yesterday.they grouped about 1 in. with 53g Imr 4350.i dont like light 100g bullets for deer.

i am disapointed in 120g Nosler partitions i paid high for them as they are hard to find .may need to try different powder??

what say you?

Bull

 

[AJC1]

I did the dollar bill test . good clearance between stock and barrel. i didnt mention that i sbot some 100 g Hornady SP yesterday.they grouped about 1 in. with 53g Imr 4350.i dont like light 100g bullets for deer.

i am disapointed in 120g Nosler partitions i paid high for them as they are hard to find .may need to try different powder??

what say you?

Bull

Isn't 4831 a good powder for that chambering. Never loaded it, but making a significant change may make a bigger difference...

 

[tominboise]

I used to think that my guns were wearing out. Then I realized I'm getting old and my eyes are wearing out. My heartbeat is different. My muscles are weak. I just suck.

Yes, I shot some off hand practice today with a 22 rifle. Practicing for chickens at 50 yards. Shooting at a 2" adhesive dot. It was quite an eye opener. Left arm muscles just seem to twitch a lot, and movement of the cross hairs all over the target.

I used to be able to run the chickens at will. Sucks to get old, I guess. But I am still vertical and pulling a trigger, so it isn't all bad.

 

[AJC1]

Yes, I shot some off hand practice today with a 22 rifle. Practicing for chickens at 50 yards. Shooting at a 2" adhesive dot. It was quite an eye opener. Left arm muscles just seem to twitch a lot, and movement of the cross hairs all over the target.

I used to be able to run the chickens at will. Sucks to get old, I guess. But I am still vertical and pulling a trigger, so it isn't all bad.

Are you bracing your arm on your body for maximum support?

 

[Blue68f100]

Are you bracing your arm on your body for maximum support?
View attachment 1185584

After 4 back surgeries by back does not bend like that anymore. Most all my shooting these days are off a bench/rest. I cans shoot pretty decent sitting down on the ground, just may have problem getting back up..

 

[tominboise]

Are you bracing your arm on your body for maximum support?
View attachment 1185584

I try. I seem to switch back and forth between the standard silhouette hold and the standard off hand hold. Not sure why. I've shot most of my life using the standard offhand stance, so it's hard to teach the old dog new tricks. But I am working at it.

 

[troy fairweather]

Barrel has stopped speeding up after that many shots, your load may have been just on the edge of a accurate node and now it maybe on the other side. So after checking what others have posted and a good clean I'd work up a new load, also how many shots on the brass maybe time to anneal it could be inconsistent neck Tension.

 

[AJC1]

Barrel has stopped speeding up after that many shots, your load may have been just on the edge of a accurate node and now it maybe on the other side. So after checking what others have posted and a good clean I'd work up a new load, also how many shots on the brass maybe time to anneal it could be inconsistent neck Tension.

Probably the same with seating depth.... throat now stabilized.