I have one rifle that just wouldn't group with anything. So, I ran the borescope down it and here are just a few pics:


this one is just down the barrel from the chamber



This one about halfway down the barrel.



And this one is just inside the muzzle (look in the lower right-hand corner and you can see a bit of the muzzle)

Rebarrel or try some of the Tubbs bullets?

What's the cartridge and round count?

^ this

That doesn't look all that bad....I've seen worse shoot well and I've seen not near as bad shoot bad. They are all different. Odds are if you think you need a new barrel, you do....in my experience, because we don't know that barrel or the previous accuracy like you do.

Tubbs bullets are never the right answer.

The first picture is the fire cracking near the chamber area, which is normal. The fire cracking will become bigger the more you shoot it. That looks fine.

On the other 2 pictures, especially the one about half way down the barrel, that is pitting from rust. That is what your problem is. The fire cracking is 100% normal and not that bad. But the pitting seen throughout the barrel, that's your issue. The rifling edges are pitted and rusted out. Tubb bullets won't help you. That barrel is rusted and pitted out. If you've tried some hand loads and are getting open and random patterns, then a new barrel would be your answer.

Thanks for sharing the photos, never played with a bore scope but the pitting sure looks a lot worse than what I would figure was "ok".

Cartridge is a .256 Newton. Rifle made in 1915-16 on a Mauser action. Round count is unknown.
I couldn't figure out why it wouldn't group. I've shot shotgun reloads that patterned better.
Finally ran the borescope and took about 20 pictures. The one showing mid-way down the barrel is fairly common, in short, it's like that most of the way down the bore.

Best pattern I've gotten has been in the 4-5" range at 100 yards.

Time to save some $$ up and see about a new tube on the old lady.

What bullet weights have you tried. With a factory 1:10 and that much wear you may have to stick to 120s. If those don’t fly then I’d say new barrel time for sure.

That was a hot cartridge for its time if I remember correctly. You got 103 years out of the barrel though.

If you went with a short bullet,(dropped bullet weight) and tried something easier to spin, it might help. But when you get that kind of rifling damage, it will chew up the bullet also and be difficult to shoot well.

I've tried:
123 Scenar
125 Partition
130 AB
129 ABLR

I'm betting whoever put it up for auction either knew the barrel was in this condition or didn't want to mess with making brass or, just wanted the $$$.

dang, that barrel looks trashed to me, Intergranular corrosion, black rust and heavy pitting is not normal to me

As others have stated it looks bad.
If it was a common rifle of the last half century I would say replace the barrel.
But it's a 100+ year old custom.
I would leave as is and use it at locations where close enough the poor accuracy is not a problem.

If it was an inherited family rifle, I wouldn’t rebarrel it. But, if you bought it to shoot and hunt and it has no family history or serious value as an antique, rebarrel it.

I would want to keep it as original as possible. I would think you can have the original barrel bored and sleeved to the original caliber. This is probably more expensive than a new barrel but a new barrel would in my opinion defeat the purpose of owning the rifle. I remember when you got that rifle, if I remember correctly you had wanted one for a while.

Bet TDK on here can do it for a small fortune. It would be correct and good for a lifetime of enjoyment.

Anyway, that’s my opinion.