Gun Re-barrel Accuracy Issue

[Ramem7mm]

Back story: My dad’s rifle is the gun with the issue and I am trying to help him figure it out. The original rifle is probably a 1980’s era Vanguard Weatherby chambered in 7mm Rem Mag. Last year when at the range the gun would not shoot consistently and have fliers opening the group to 1-3 MOA, Scope rings, and base all Nightforce (scope was also removed from the gun, put on a verified gun and confirmed not a scope problem). Factory ammo was also being used. Hornady Precision Hunter 162 ELDX and also Nosler 150 Gr E-Tips. Through a bore scope analysis the rifle had significant wear with what appeared to be pitting and erosion on the rifling and significant fire cracking through most of the barrel. He chose to have a local smith re-barrel (Hart Barrel) with a similar to factory contour to keep the nostalgic look. The smith also installed action pillars and bedded the receiver.

After receiving the gun from the work being completed and scope reinstalled the accuracy has not improved and at 100 yards the factory ammo (Hornady Precision Hunter 162 ELDX (40 rounds fired) and Nosler 150 E Tip (50-60 rounds fired)) is greater than +2”. The barrel has been cleaned several times as well to keep the copper fouling out between the two types of ammo. Barrel is not being over heated when sighting in. Bore scope inspection shows no visible issues at the throat, rifling, or the crown. No residual copper or carbon fouling is left either. Scope torque has been reverified, action screws are at 45 lbs, barrel is floating and not touching the stock.

At this point looking for advice on where else to look for a solution to fix the problem.

Its assumed that factory ammo of this choice should produce far better groups than what is being reflected on target and that reloading would not remedy what is happening.

Coincidentally I have a 243 Winchester Vanguard Weatherby with factory barrel that does the same thing. That will be for a separate day to fix that one.

 

[ResearchinStuff]

Are you shooting off a lead sled?

 

[LeftyWilbury]

I love my tikka 7 mags and if I limit shot count to under 5 shots I could possibly say I shoot under 1MOA at 100 yards off of a solid rest...but 2 MOA is more realistic. I'd venture a guess that 2+ is just what that rifle with that stock and in that caliber are going to shoot.

I'd be definitely disappointed if my 243 was doing that.

 

[Wrench]

Have you verified that the base screws and front action screw do not touch the bolt?

 

[SDHNTR]

You only shot two types of factory ammo. You cannot yet conclusively state the barrel is inaccurate.

 

[Ramem7mm]

I have also shot his gun and when I have shot it I am not shooting off a lead sled(nor is he), those things are terrible. Mainly shooting off bipod and rear sand bag.

I personally have 2 each 7 mags and both shoot exceptionally well with my reloads in sub MOA off bipods and rear sand bag. Other guns I own I can obtain sub MOA as well so the shooter can be removed form the equation.

Bolt does not touch screws. verified looking through bore scope.

Thanks for the replies

 

[Ramem7mm]

You only shot two types of factory ammo. You cannot yet conclusively state the barrel is inaccurate.

This has been taken into consideration and not yet overlooked that factory ammo testing has been limited. Both boxes have a proven aspect from using in other personal rifles so they seem to hold a little bit of weight. Reloading has been considered but like I mentioned I would expect better accuracy from new equipment with as much advancements that have changed from over the years.

 

[SDHNTR]

This has been taken into consideration and not yet overlooked that factory ammo testing has been limited. Both boxes have a proven aspect from using in other personal rifles so they seem to hold a little bit of weight. Reloading has been considered but like I mentioned I would expect better accuracy from new equipment with as much advancements that have changed from over the years.

Unfortunately, your assumptions are incorrect. Accurate ammo in one rifle is completely meaningless to another. Advanments in technology are irrelevant too. Either the ammo jives with your chamber and barrel or it doesn’t. I could load you up some ammo that is concentric to .001” TIR, powder charge weighed to within .02 gr accuracy, shoulder to base length and seating depth all within .001”, with the best and latest and greatest components available. Then you could feed that ammo into a rifle built with the best custom action and barrel available, and it could still shoot like chit if your barrel doesn’t like it. Just how it is. Barrels all have their own unique preferences and you need to find what it likes.

 

[Dmoua]

How heavy is the trigger? How light is the rifle?

I have never owned a Hart barrel but all my Bartleins and Proof barrels have shot great with ammo that I threw together just to season the barrel.

 

[Ramem7mm]

How heavy is the trigger? How light is the rifle?

I have never owned a Hart barrel but all my Bartleins and Proof barrels have shot great with ammo that I threw together just to season the barrel.

The trigger is a Timney set around 2.5 lbs. I haven’t actually weighed the rifle but it weighs as much as a couple of my other guns that are in the 10-11 pound range.

 

[Ramem7mm]

Unfortunately, your assumptions are incorrect. Accurate ammo in one rifle is completely meaningless to another. Advanments in technology are irrelevant too. Either the ammo jives with your chamber and barrel or it doesn’t. I could load you up some ammo that is concentric to .001” TIR, powder charge weighed to within .02 gr accuracy, shoulder to base length and seating depth all within .001”, with the best and latest and greatest components available. Then you could feed that ammo into a rifle built with the best custom action and barrel available, and it could still shoot like chit if your barrel doesn’t like it. Just how it is. Barrels all have their own unique preferences and you need to find what it likes.

Got it. I’m not discounting the limited testing of the selected ammo. Thank you

 

[Dmoua]

The trigger is a Timney set around 2.5 lbs. I haven’t actually weighed the rifle but it weighs as much as a couple of my other guns that are in the 10-11 pound range.

Gotcha. I’m just wondering if it’s something else besides the barrel since it shot poorly before the barrel work and still shooting bad after.

 

[TaperPin]

The gun may have a week firing pin spring, or junk inside the bolt causing erratic ignition and bad accuracy.

 

[yfarm]

Go to Copper Creeks website, read about chamber measurement. Rather than blindly cast about for a different ammo buy a load development pack. My son and I don’t reload, some of our rifles shoot anything well(RPR given to him from a friend) others Barrett and Weatherby. are very finicky down to one load. Keep ruminating about measuring the chambers and ammo.

 

[Wrench]

At this point, I'd blue the lugs....sharpie (back side and edges) smoke....something you'll see and put a piece of scotch tape on a fired unsized case and close the bolt. Pull the bolt and look at contact pattern. If it's touching both lugs and not on the outside of the bolt.....you can suspect the barrel.

Have you verified it's not some super slow twist?

 

[blairmckenzie1]

im fairly certain that era weatherby action is made from a casting. a gunsmith i learned from was super leery to rebarrel those.

have you talked to the gunsmith?

 

[Ramem7mm]

At this point, I'd blue the lugs....sharpie (back side and edges) smoke....something you'll see and put a piece of scotch tape on a fired unsized case and close the bolt. Pull the bolt and look at contact pattern. If it's touching both lugs and not on the outside of the bolt.....you can suspect the barrel.

Have you verified it's not some super slow twist?

I will check lug contact as recommended as soon as I can. Just checked twist and it measured 8.5” twice, so not too slow. Thank you

 

[SloppyJ]

Have you brought this up to the gunsmith? At this point I think it's time you take it to him. It could be something inherent with the action or it could be something he didn't do right that just manifests itself similar to the bad barrel. At least give him a chance to make it right?

 

[Ramem7mm]

im fairly certain that era weatherby action is made from a casting. a gunsmith i learned from was super leery to rebarrel those.

have you talked to the gunsmith?

I haven’t talked to the gunsmith yet. The guy wasn’t hesitant to work on it because of the challenges to get the barrel off and the metric threads from what he explained.

I did also notice this evening that the rear action screw was making a lot of contact with the pillar wall and after looking at it the pillar was not centered. I was able to open the hole up just enough to alleviate the screw from hitting the sidewall and going into the action a lot easier. Not sure how much that will change things but maybe alleviate undue stress in n the action.

 

[Wrench]

I was just coming back to mention that pillar contact can affect accuracy. You can run a drill through the pillar and see if it helps.