20140120

a chamber cast of Anduril

I took a chamber casting of the Remington 600 known as Anduril.


At the neck of the cartridge case, diameter is .348".  At the freebore, it is .312".  After the rifling has begun, it's .310"

that sounds a bit over.  Any ideas, readers?  Is this barrel d00med?

Update:  using my l33t Bene Gesserit training, I managed to slip the caliper on the cast just forward of the freebore, between the lands, and it's really .308" in there, and I'm not scraping Cerrosafe off of the casting.  Maybe not d00med.  But the very short magazine box plus the approximately .225" of freebore really limits bullets that will touch the rifling.  Would almost rather have the barrel pulled, lop off one or two threads of barrel shank, twist it back in and have a new chamber cut with less freebore.  

Update 2:  gotta keep in mind that Cerrosafe expands to .0025" oversize after it has done cooling, in another 7 days or so; this cast was taken Monday afternoon.  That expansion is on the same scale as my measurements tell me the chamber is oversize in diameter.

And we found SAAMI specification drawings.  The freebore is supposed to be only about .08" long.  That may be the only problem with this chamber. 

4 comments:

jed said...

Uh, whatever you say, Reverend Mother Antelope.

Not being familiar with the 600, I did a search, and came up with a bolt-lock Safety Modification Program. Well, I suppose you're up on that. Just thought I'd mention it.

And your link to Anduril is a 404.

Can't help you with the d00med thing. Other than hey, if you're not happy with it, why not have it re-cut?

Fûz said...

404!??!
some guy on a board said that Remington chambers tend to have far too much freebore. I agree in this case. The chamber is also so loose that a case fired from it will not grip a new bullet, even if neck-sized. Also, I'd have to seat bullets so far forward in the case, to touch the rifling when chambered, that they'd be too long for the Rem 600's cheesy bent-sheet-steel magazine. I want the rifling starting closer to the bolt face, that means shorten the barrel from the chamber end, and cut a new chamber.
Should be cheaper than a new barrel, since a new barrel would require a lot of the same work.

jed said...

Yeah, I always listen to that some guy. ;-)

Well, if you can't reload your empties, I'd agree that it needs fixed for that reason alone. Can't speak to the freebore issue in general, because I haven't taken castings of either of my M700s.

Can't imagine any scenario where getting a new barrel would be less expensive, and get you where you want to be. As long as the rifling has enough life left in it, that is.

Fûz said...

"rifling . . life left in it" my micrometer sees about .002" difference between land and groove, less than a caliber in front of the freebore. It's just that chamber.

Taking castings is straightforward. The Cerrosafe is handy but you could use paraffin instead.

We'll be talking to a couple of shops this weekend.