Bolt Action .450 Bushmaster

[Dixiejack]

This topic has probably been discussed before, but I did a search and didn't find any reference to my idea.
Thinking about taking a Remington 700 SPS Varmint left hand action rifle in .308 Winchester and having it rebored/chambered to .450 Bushmaster. Have the barrel cut down to 20". My major concerns are finding a gunsmith to do the work of reboring/chambering and shortening the magazine by putting a block in the existing magazine box or replacing with a .223 magazine. The case rim on both (.308 & .450) are .730" so bolt and extractor should not be a problem. 
Any and all feedback would be greatly appreciated. 

[Bigeasy]

Looking at the 450 Bushmaster cartridge specs, it should work using a .308 win action and barrel.  BUT, how about a .450 Marlin?  More potential when loaded up, and still can be loaded down for plinking loads.
 
Max. OAL on a 308 is 2.810.  OAL on a 450 marlin is 2.550, so magazine length should be good to go.  Rim on the Bushmaster is .473, and is .532 on the Marlin.  The rim on a 416 Remington, for example, is also .532, so I am guessing the bolt face of your 308 bolt could be opened up, though I am not familiar enough with the Rem. 700 to say for shure.. Still, it might be an alternative to look at.
 
Larry

[Dixiejack]

Maximum OAL of .450 is 2.26, the same as a .223.  That's why I'm thinking that the magazine on the 700 .308 would need to be shorten or replaced. Also, I really don't want to get back into handloading. You do have some good suggestions. Thanks.

[Bigeasy]

Was just thinking out loud...  As far as the magazine on your 308 model 700 (I am assuming blind or hinged floor plate, not detachable), it should work fine as is.  I believe they share the same magazine in the short action line (223, 7mm/08, 260, 308, etc)
 
Larry

[Dixiejack]

If they do, it would be a pretty straight forward modify.  The diameter of the barrel is .82, so there is plenty of steel for a larger rebore.  Now to find a gunsmith.  Years ago, Cliff LaBounty did a rebore/chamber for me, but I hear he has retired.  I'll start doing an internet search.

[Flynmoose]

You might give Wayne York at oregongunsmithing.com, located in Pendleton, Oregon a call. He does rebores and has a good reputation. His phone number is 541-278-4177.
FM
 

[Dixiejack]

Thanks, Flynmoose.  I appreciate the information.  I will call him.  Let you know what he said. Larry, thanks for your input and putting me on the right track.