7mm-08 to .284 Winchester?

[AR Shooter]

Am building a .284Win for long-range work and am wondering if it as simple as having the 'smith who is building my .284 rifle run the same reamer into my Rem 700 7mm-08 to convert it to .284, as well. In for a penny, in for a pound.

 

[TonyR]

Am building a .284Win for long-range work and am wondering if it as simple as having the 'smith who is building my .284 rifle run the same reamer into my Rem 700 7mm-08 to convert it to .284, as well. In for a penny, in for a pound.

I think you should be fine as long as the 284 chamber neck is larger than the 7-08 chamber neck. All of the other cartridge dimensions of the 284 are larger than the 308 Win, at least according to QuickDesign. If you have a "no-turn" 308, there may or not be a problem with the 284 Win. According to QD, the 284 SAMMI neck is begger than the 7-08 but it would depend on the reamer used to cut each chamber.

 

[Preacher]

That is not a problem at all, you'll enjoy both of them I'm sure....

 

[338 Mollett]

Cut off an inch and re chamber no problem.If you have a long barrel to start with.Other wise you might want to get a new barrel for the planned long range work.Also have your smith look to see how far the checkering has gone down the barrel that might make your choice for you.

 

[AR Shooter]

Thanks, all. That's pretty much what I was hoping for.
With only ~300 rounds through my hunting rifle, I'll risk just a re-chamber. Maybe set the barrel back one turn, at most. Let the 'smith decide. That's why we pay them the big bucks.

 

[338 Mollett]

You're gonna have to take off enough so the pilot on the reamer can enter the bore deep enough to provide a true guide of the reamer.

 

[idahoorion]

Check to see how the empty 284 cases load from the mag. maybe some alterations in store cause of that fat 284 case.

Idahoorion

 

[338 Mollett]

I was wrong it can be bored out ,that's why I don't smith my own guns,never could figure out where the spark plug went.

 

[Erik Cortina]

You have to set it back .165" at least so the 284 neck will clean up the entire 7mm-08 neck. I would personally set it back .200" - .250" after borescope inspection of throat.

 

[XTR]

You're gonna have to take off enough so the pilot on the reamer can enter the bore deep enough to provide a true guide of the reamer.

That's the one my smith was telling me can be a PITA when you get into re-chambering stuff.

 

[Kings X]

Trying to open the chamber is a lot harder than just lengthing it. Say for 7-08 to 280 or 280 Improved is not a big deal.
But going fatter can cause the reamer to chatter. I have never had good luck trying to go fatter. You almost have to bore about the shoulder diameter and then chamber. Do this in many steps - like bore .200" deep and ream, bore .200" deep and ream.
Good luck.