converting 7mm Rem Mag

[IdahoCTD]

The 26/28 Nosler cases are based on the 404 Jeffrey but the case head is .534 much like the RUM and SAUM based cases. So you don't have to do anything when converting to them from a belted magnum (.532). As has been said....the feeding is another story.

Here is the 26 Nosler SAAMI sheet
http://static.squarespace.com/stati...e6f5ea59cc6/1392421251029/26_Nosler_SAAMI.pdf

 

[shortgrass]

28 Nosler is based on the 404.

I based my idea on the winchester 7mm mag that I have, it is more work than I want to deal with. I decided to scrap the idea all together.

Your 'research' was incomplete. The body of the .260/280 Nosler case might be based on the Jeffery, but the rim is that of the std. magnums. You might want to take a look at www.saami.org for industry stds. Industry standard drawings of MAX cartridge and MINIMUM chamber dimensions are there. The .260 Nosler is listed under "New Cartridges", the 7mm Rem Mag is in the "rifle" list. Reliable feeding would be the main challenge. Mag boxes for the RUMs/WSMs/RSAUMs have that diamond shaped notch in the mag box wall for that large diameter shoulder to fit into. It can be done, but it's a PIA! Conversions like this are for the hobbyists, where time isn't a concern. Many don't have the fortitude to follow it through. Lots of unexpected 'hic-ups" and challenges to be met with, along they way. One might try shortening the extended Wyatts box, that has the cut outs, but that's a lot of work for little gain other than to say you have rifle chambered for the "new" Nosler cartridge.

 

[Punisher]

Your 'research' was incomplete. The body of the .260/280 Nosler case might be based on the Jeffery, but the rim is that of the std. magnums. You might want to take a look at www.saami.org for industry stds. Industry standard drawings of MAX cartridge and MINIMUM chamber dimensions are there. The .260 Nosler is listed under "New Cartridges", the 7mm Rem Mag is in the "rifle" list. Reliable feeding would be the main challenge. Mag boxes for the RUMs/WSMs/RSAUMs have that diamond shaped notch in the mag box wall for that large diameter shoulder to fit into. It can be done, but it's a PIA! Conversions like this are for the hobbyists, where time isn't a concern. Many don't have the fortitude to follow it through. Lots of unexpected 'hic-ups" and challenges to be met with, along they way. One might try shortening the extended Wyatts box, that has the cut outs, but that's a lot of work for little gain other than to say you have rifle chambered for the "new" Nosler cartridge.

I actually didn't check SAAMI website. I took the info from Wikipedia which says see 404 Jeffries.

 

[Edd]

One might try shortening the extended Wyatts box, that has the cut outs, but that's a lot of work for little gain other than to say you have rifle chambered for the "new" Nosler cartridge.

Why would you need to shorten it?

 

[shortgrass]

Why would you need to shorten it?

Shorten it if milling the feed port would be needed,,, block it if it will fit in the existing 'hole'. The Wyatts box with the diamond shaped cut-outs , that I've seen, are for the RUMs. That would be 'more box than needed. The shoulder of the cartridge needs to be where the diamond shaped cut-outs are in the mag box wall for proper 'stacking' and feed. SAAMI spec trump Wikipedia every time.

 

[mountainman56]

If you're dead set on a change there's always the 7mm-300 Win mag. Get the chamber reamed, acquire some 300 brass and a set of dies and you're ready to go.

JM2C

 

[pig ranch deadeye]

If you're dead set on a change there's always the 7mm-300 Win mag. Get the chamber reamed, acquire some 300 brass and a set of dies and you're ready to go.

JM2C

Don't overlook the all-time classic, the 7mm Mashburn Magnum. Give the .300 win mag case one pass through the sizing die, and PRESTO! It holds maybe 6-8 grains more powder than the 7 Rem Mag. Not ridiculously over-bore. "Not to big. Not too small." The 7mm Masnburn has plenty of neck length, another advantage.