Some years ago I had a gunsmith build a .300 WMR on a Sako AV action. I would now like to re-chamber the rifle to a non-belted caliber (6.5-.284). Can I buy a non-belted bolt and simply replace the belted one?

quote:

Originally posted by Roaddog:
Some years ago I had a gunsmith build a .300 WMR on a Sako AV action. I would now like to re-chamber the rifle to a non-belted caliber (6.5-.284). Can I buy a non-belted bolt and simply replace the belted one?

First, what is a .300 WMR? I'm not familiar with it and with all of the new and wildcat rounds out there I hesitate to guess which case this is on.

Second, if it uses a .530" bolt face (for a belted magnum or RUM-head case), then your chamber will be far too large to rechamber for a cartridge based on a .284 case. You'll have to rebarrel.

Then you'll need a new .473" bolt face which you could achieve if you could locate a bolt for your Sako (not easy!). Or, a skilled gunsmith might be able to bush your magnum bolt face down, but this is a bit dicey.

But your ultimate problem might be that your magazine feed rails are too wide for the (perhaps) smaller .284 case, allowing the .284 case to pop out of the magazine prematurely.

You would be far better off finding an action for a .473 bolt face and working with it.

The cartridge is a .300 Win Mag...sorry for the confusion. I was planning to re-barrel to 6.5-.284 but I wasn't sure about the bolt. I thought maybe I could just replace the existing magnum bolt for the smaller one. I think I understand what you are saying about the magazine. Oh well.

Actually, the "magnum" size magazine rails of your A-5 will probably hold the .284 case just fine. The .284 case is .500" in diameter, which compares to about .510" for the body of a belted magnum. I was originally a bit worried that your rifle was currently chambered for something like the .300 WSM with its somewhat larger body (.550") and might have had the feed rails slightly widened.

At any rate, it is simple enough to test by placing some .284 or 6.5-284 ammunition in the magazine and seeing if they feed okay.

I still think that the challenge might be finding a .473" bolt for your A-5, but maybe you have one spotted. In my experience, Sako's tight manufacturing tolerances make exchanging bolts between actions very little problem.

save yourself ALOT of trouble .. 6.5 rem or 264 win .. the latter being the best drop in replacment.. if you just want 6.5x284 performance, use rel25

Jeffeosso... I might be interested in a 6.5 Rem conversion. What would you use for brass?

not being a smart alec here, i'd use remington 6.5 remmag brass, available at midway
https://www.midwayusa.com/view...uctNumber=1601110222

The 6.5 Rem Magnum is so close in shape and case capacity to the 6.5-284 that any difference in performance would be negligible.

As Jeff suggests, 6.5 Rem brass is still cataloged (although sometimes it is "seasonally unavailable").

I owned a 6.5 RM years ago and used cut down .264 WM brass in it, but any belted magnum case will serve as feedstock. Perhaps 7mm RM would be the most avaialble and least expensive. Or hell, if you've got a supply of the .300 Win Mag brass and you're about to ditch the barrel, just use that. Judicious annealing may be useful if the brass has been fired more than once or twice.

I hadn't tried Midway. I couldn't find the 6.5 Rem brass anywhere else I looked.