Update: Resolution...

As I had suspected a little, and hoped a little, the issue required only simple fitting.


I cleaned the barrel and bolt, applied DyKem and re-assembled the gun... I cycled the slide and let it jam up good a couple of times. I then removed the bolt from the slide and was presented with only two contact points, but they were substantial. A close look with a magnifier showed tiny metal shavings on the bolt. These shavings were left there by the barrel lug tips, and there is almost no gouging or damage to the bolt. The barrel material is a good bit softer than the bolt, so all is ok.


An important note... this post is referencing the replacement barrel. In the pictures above, of the bolt, you can see two places where the FIRST barrel gouged/scraped the barrel lugs... the new barrel hit EXACTLY the same. This could mean that other barrels from this batch might only need this tiny bit of fitting to work perfectly. This entire process took about an hour... except for pouring ammo through it for testing after the first and only adjustment... that took another hour.


In the image above, you can deduct which lugs were trimmed and re-polished... but here is an image marking where I removed a small amount of material.





Basically I rounded these sharp corners with a diamond bit, then polished them smooth. I didn't remove much material really... for reference I maybe made roughly a .020 radius on the marked corners. This made 100% clearance to the bolt.


One thing I did that I do on all my barrels that this barrel did need... I used a round brush in a Dremel tool to reach behind the barrels locking lugs and polished the inside of them. They needed it. This would probably correct after a good number of rounds is run through the gun, but why not just polish them? I do this to almost all my new barrels, but the used barrels (with the exception of one) don't seem to need it.


So I took it outside, did a 9+1 and slowly fired the rounds (Winchester Super-X)... then I put 100 rounds of Aguilla through it. Flawless... and you can not limp-wrist this barrel... and I have not custom fit a gas piston for this barrel, as it didn't need it. The gas cylinder is absolutely perfect in dimension to my other Israeli made barrels.
While 110 rounds isn't a thorough test by any means, I am confident all is well with this barrel.


In with the Devils Advocate...
I am happy right now that my barrel was easy to repair. I am NOT happy about paying $500 for a barrel that first was cosmetically unacceptable, and not functional as well. Magnum Research DID apologize and took full responsibility for the barrel and offered a refund or replacement at my discretion. They even tested the replacement barrel for fit on a gun... and it didn't work... but I asked for the barrel anyway, as I was confident I could fix it.

Anyway...
Now I have what is probably the final barrel for my collection and it seems to work better than the American, current production barrels also.

So if you get one of these 10" .357 barrels and have bolt jamming issues, and don't want to sent your gun back, it might be as easy to fix as mine was... did I mention I couldn't limp wrist this barrel at all? Excellent. I will be putting some rounds through this barrel in the next few weeks, and will report back if any issues come up with function.

MrBlackCat