I have only a very limited amount of machining experience, garnered 20-plus years ago in college. I have not made a chip since then.

I have this 300WSM rifle in a long action. I have been trying to come up with a wildcat for it that will save the barrel, but the cases available are not helping. The 300WSM is .555 at the lower datum diameter; the only good candidate, the 300RUM, is .550 there. So I thought: Is it possible to move the shoulder of the barrel forward by half an inch or so and cut the new thread to match the existing? If I can, I can use the original barrel, enjoy the accuracy benefits in cutting a new, tight chamber (has a SAAMI chamber now) and keep my muzzle brake. Is it possible? I am thinking getting the new thread timed to exactly match the existing is where the problem may lie. I know if it's even half a red hair off, the job is trash. Good thing I had Krieger put a four-inch breech length on the blank...

The job you describe is relatively easy and can be done by any experienced smith. The operation of 'picking up the thread' is a basic one and can be done by any good machinist.

What's wrong with the chambering as-is? Just curious.
Regards, Joe

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What's wrong with the chambering as-is? Just curious.

Feeding is erratic. I have to give the bolt a sharp slap forward to pick up the cartridge and chamber it. I might get 80% to chamber on the first attempt. What it will do is put any flinching on display for all to see when you pull the trigger and get just that deafening click...

Sounds like it needs feeding work instead of a rechamber. If you rechamber with another fat cartridge that'll clean up that WSM chamber, you'll have the same issues. If I understand you right, the case diameter is larger that the rails are opened up for. Thus the cartridge sits too low in the mag for the bolt to pick it up properly. If you like the cartridge just fine and it sounds like it is accurate, take it to a compotent smith and get him to make it feed. Shouldn't be that difficult. And much cheaper than the rechamber and still having to work out the feeding.

David

Opening up the feed rails a bit might do it. The 'smith who built it had a 300WSM of his own on a long action M70. I figured the only way to get the extractor to grab the rim was to convert the thing to a longer cartridge. Too bad any gunsmith work at all takes eons...

The rifle is a Montana Rifle Company M1999-- part of the charter run. The action was delivered in November of 2004. The rifle has shot a .154 at 100 yards and will generally shoot a sub-half MOA group of five at 300 yards.

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Originally posted by homebrewer:
...The rifle has shot a .154 at 100 yards and will generally shoot a sub-half MOA group of five at 300 yards.

I'm being completely serious here...If it's that accurate, why not just load single shot?

quote:

why not just load single shot?

Because I want the ability to throw 'em downrange faster than one at a time. Loading singles requires me to come completely off the rifle, screwing up my stance and everything that goes into making the shot. The gun has a magazine that will hold at least three, so I want it to do what it is supposed to do...