converting 7mm Rem Mag

[degreen]

My dad has a Winchester model 70 in 7mm Rem Mag that the stock has been busted on. I was wondering if it could be re chambered in .28 Nosler?

 

[gohring3006]

Barrel length?

 

[Deleted member 46119]

Yes it can be rechambered to 28 Nosler.

Some magazine work may be required.

As gohring3006 intimates, barrel length may be something to consider.

If it is less than 24" IMO keep it a 7RM.

If 24 or longer, you can gain some from a 7RM.

If 26 or longer, you're golden.

 

[specweldtom]

Barrel length is a factor. If it's 24" it's marginal on any cartridge that will clean up the 7 mag chamber. The 7 STW is a possibility and will just barely clean up the Rem mag chamber (at the original shoulder).

One caution; The longer cartridges may not leave enough barrel thickness out in front of the original chamber.

Tom

 

[degreen]

Confused? 28 Nosler is the same length as the 7rm only bigger in diameter. .550 verses .532 at the belt. So reamer should clean up the chamber. I'm not sure of barrel length. I am sure that it is the standard length. 22" or 24" what ever Winchester put on their magnum rifles.

 

[IdahoCTD]

The 28 Nosler is a bit longer at 2.59" versus 2.50" for the 7RM. Your biggest concern would be if the 28 Nosler reamer has a neck diameter larger than the factory chamber so you don't have a stepped neck from the old 7RM chamber to the new 28 Nosler chamber. A call to a reamer maker should give you this info.

 

[Garycrow]

I'm not sure of barrel length. I am sure that it is the standard length. 22" or 24" what ever Winchester put on their magnum rifles.

Winchester puts 26" barrels on their 7mm rem mags unless it's a featherweight which gets 24".

 

[Deleted member 46119]

I looked at the chamber of the 28-Nosler rechambered from 7RM. No issiues with the SAMMI reamer spec.

 

[degreen]

Thanks for the info. guys. Looks like another project is in the making.

 

[Punisher]

This will be possible, but not easy. Is it a push feed or CRF?

You need to open bolt face and do extractor work.

 

[shortgrass]

Why change the cartridge on a factory barrel? If it shoots now, leave it alone. If it's not shooting up to std., just changing the chambering won't help. .002" difference in bolt face dia. shouldn't matter,,,,, but the magazine box sure might!

 

[Punisher]

Why change the cartridge on a factory barrel? If it shoots now, leave it alone. If it's not shooting up to std., just changing the chambering won't help. .002" difference in bolt face dia. shouldn't matter,,,,, but the magazine box sure might!

This is a winchester. Not a Remington with .543 mag bolt face.

 

[shortgrass]

This is a Winchester. Not a Remington with .543 mag bolt face.

Makes NO difference, a magnum bolt face is a magnum bolt face (and thats .532"- .534" not .543). Measure a few, most magnum bolt faces are in the .540+" range for clearance, regardless of manufacture. The PF or CRF extractor might need attention, though,,,,, but , then again, maybe not! Magazine box, feed rails and ramp would be the major issue. I've done a couple of RUMs on Win. 70s that were oriinally .300 Win. Mag./7mm Rem Mag,, no bolt face work required, lots of milling for the longer mag box and a "loaded round extraction notch", but NO bolt face enlargement. The .260/.280 Noslers are the same on the head end as the RUMs. And I do the work, I don't off it send off to someone else.

 

[Punisher]

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.