Hello all and happy new year! I am calling out to those of you with barrel life experience. I recently aquired a savage 340 chambered in .222 the gun is in rough shape and shot poorly. The last inch or so of the muzzle looked sandblasted inside? So I have trimmed and recrowned the barrel with excellent results until my old steel tube weaver took a dump or so I thought. I swapped over to a NIB classic series and the gun is shooting patterns still I've retorqed the mount changed rings and scopes to no avail along with multiple ammunitions. Is my barrel toast ?

Possibly

Have you checked the headspace?

Not yet dont have any gauges to do so I could try tape method as a rough idea I suppose

With a piece of factory ammunition it will close on one piece of masking tape easily but not on two

Might try some copper remover in the bore.

That was my thought as well could be fouled very hard to see.

I too would give the barrel a deep cleaning. Note also it wouldn't be the first time a fella was unlucky enough to have two bum scopes in a row. Any way to try a third one?

Don't set your accuracy goals too high. I've had experience with two 340 .222's and neither one shot better than around 1.5 MOA.

Are you shooting factory loads? If handloads maybe it's also time to check concentricity of the rounds. Badly out of whack bullets will yield results much like you describe.

Nib scope is a unknown. Now you have increased the possibilities . Try a proven scope. But first....
Check the goofy barrel band for tightness. If the last guy was misguided enough to toss it and try "free floating" the barrel go to gunpartscorp and get one.
These 340's need it for accuracy.
Also what weight bullet you using? The 340 in 222 uses a 1-14 twist. It needs light or short for weight bullets.

I have scrubbed the guts out of this barrel, using factory ammunition and have tried 3 different brands the gun shot beautiful groups after I trimmed and recrowned. Ran several boxes through it over a period of a couple months and then next time out it started shooting everywhere like a bad scope. Barrel band is on it, what should it be torqued to? 50gr bullets btw

I would try some different torque settings to see which worked best. I doubt those figures have ever been published.

Frankly I'm stumped. But also in similar circumstances I found the scope(s) to be the culprit. Crazy idea: try it with the iron sights. It won't deliver the accuracy that a scope will of course, but it'll tell you if the scope(s) are at fault if it shoots consistently with the irons.

The headspace is gone, now I need to find a barrel. Nunrich doesn't list any in stock besides a .223 anyone got parts for one of these they'd sell ?

The headspace is gone, now I need to find a barrel. Nunrich doesn't list any in stock besides a .223 anyone got parts for one of these they'd sell ?

Uh huh....

I could transform it into a .223 fairly easily I suppose, just hate to let the triple deuce thing go it's a sweet deal when it all goes right

Have you tried reloading that fired brass with only neck-sizing?

How would headspace cause an abrupt loss of accuracy? Excessive headspace doesn't happen abruptly, it's a gradual thing. (Unless of course a handful of particularly nasty high pressure cartridges are fired, but even still...)

Excessive headspace is certainly a detriment to the shooter's safety (if egregious enough), and a detriment to case life, but effecting accuracy especially in this manner? I dunno....

I am only running factory ammo I cant understand why it just went crazy one day either. The muzzle end looks terrible inside just eyeballing it and from what I can see the throat isn't great but according to a headspace gauge this thing is toast

The increased end-play in the chamber, causes the cartridge to not be positioned uniformly in the chamber from shot to shot. So the bullet wouldn't contact the rifling in exactly the same position every time one left a case..

Actually there are probably more contributing factors piled on. The 340 isn't the strongest action in the world. Some previous owner probably roached the barrel with hand loads thinking they were shooting a Winchester model 70 or otherwise similar.

Yes, to a degree, but I still don't think it would explain the thing going whacky all of a sudden. Besides the extractor would tend to hold the case head back against the bolt face - it's when the case stretches forward to fill the chamber that separations and such occur. I'm not saying that ultimately the blame for inaccuracy can't be laid at the feet of excess headspace, I'm merely saying that it wouldn't happen all at once. And the barrel being toast inside ditto, but that too evidently didn't happen all at once either. In fact if I read this right it was shooting ok even in its roached out state. Something egregious happened all of a sudden that has me stumped. A perfect storm of failures like Randy is alluding to I think.

Did the OP ever try shooting it with just iron sights to confirm that the scope(s) weren't at fault?

Sounds like a new barrel is in order, but I wouldn't install one without first closely examining the bolt with its single locking lug- stretching or god forbid cracking to the point of almost shearing off. The 340 has a lot of limitations, and one must ask oneself if it's worth it to spend a bunch of money, time, and labor resurrecting one.

I do not see any evidence of cracking on the locking lug but I can understand its weakness I have tried multiple new and used scopes the stock iron sight up front is gone because the barrel has been cut and recrowned. Before trimming and recrown it was keyholing the last 2in. Of the muzzle burned out.