WTF is this on rifling?

[Durable Gun]

Hello everyone, I went with my friend to the range. He has a Tikka CTR chambered in .308. He is not the best of shots but he isn't bad. I was watching his groups land and they where terrible. Like 6 + inches in sporadic patterns. I checked his action and scope ring screws and his action screws needed a bit of torquing to spec. He proceeded and his groups did not improve. I asked if he ever cleaned his bore and how many shots down the tube? His reply was 200 or so rounds fired and never cleaned. I originally suspected that his gun needed a good clean and that his gun didn't like the ammo he has been using. (The only factory ammo he has tried) . He did say that it used to shoot well when it was new. How well? I can't tell you myself. I took his gun home with me to inspect his bore and I found 2 concerning things that I haven't seen in bores. 1 - deep marring at the beginning of rifling at end of chamber. 2 - many what appear to be very fine circumferential hairline fractures along his bore. Any help would be appreciated. Thx

 

[grfox92]

Ive seen barrels with insane tooling marks way worse than that shoot legit 3/4" 10 shot groups.

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[Durable Gun]

If seen barrels with insane tooling marks way worse than that shoot legit 3/4" 10 shot groups.

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Have you seen them with marks that can't shoot?

 

[grfox92]

Have you seen them with marks that can't shoot?

Personally no.

Im not saying it doesnt happen, but I havent personally seen where a rifle was a bad shooter and tooling marks in a barrel wound up being the issue.

There are plenty of other guys on here with more extensive gunsmithing knowledge on here. Im sure some will chime in.

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[RockAndSage]

Real talk: There's about a 90% chance that it "not shooting as well as it used to" after only 200rds has more to do with fasteners coming loose somewhere, than it does with those tooling marks.

 

[Durable Gun]

Real talk: There's about a 90% chance that it "not shooting as well as it used to" after only 200rds has more to do with fasteners coming loose somewhere, than it does with those tooling marks.

Thank you.

 

[mt100gr.]

That CTR should drive tacks. Did you shoot it? What scope and mounts?

 

[Durable Gun]

I did shoot it. My groups where better. But not by much. Arken scope and mounts. Cheap shit. I did torque everything down to specs. Maybe the scope is crapping out and not holding zero.

That CTR should drive tacks. Did you shoot it? What scope and mounts?

 

[BBob]

The chambering reamer that was used was toast or it grabbed a few chips and chewed up the throat. Are those marks on only one land or all of them? The rest of the bore looks fine. The throat is the issue.

 

[Durable Gun]

The chambering reamer that was used was toast or it grabbed a few chips and chewed up the throat. Are those marks on only one land or all of them? The rest of the bore looks fine. The throat is the issue.

All but 3 lands. Thanks for the feedback.

 

[huntnful]

Not ideal but I wouldn't attribute 6" groups to those small tooling marks. Seen a few amount of them on random barrels and the guns all still shot plenty well.

 

[Durable Gun]

Not ideal but I wouldn't attribute 6" groups to those small tooling marks. Seen a few amount of them on random barrels and the guns all still shot plenty well.

Thank you. I'm currently accessing this thing.